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Uplink Single-Snapshot Frugal SLAM in Phase-Coherent Distributed MIMO Systems
Authors:
Yu Ge,
Xin Tong,
Nenad Vukmirović,
Musa Furkan Keskin,
Miljko Erić,
Petar Djurić,
Henk Wymeersch
Abstract:
We consider uplink frugal simultaneous localization and mapping (SLAM) in phase-coherent distributed MIMO (D-MIMO) systems, where a network of spatially separated single-antenna access points (APs) coherently receives narrowband, single-snapshot pilot signals from a single-antenna user equipment (UE). In contrast to existing phase-coherent localization and SLAM methods that rely on wideband measur…
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We consider uplink frugal simultaneous localization and mapping (SLAM) in phase-coherent distributed MIMO (D-MIMO) systems, where a network of spatially separated single-antenna access points (APs) coherently receives narrowband, single-snapshot pilot signals from a single-antenna user equipment (UE). In contrast to existing phase-coherent localization and SLAM methods that rely on wideband measurements and/or multi-antenna APs, the proposed frugal setting operates with the minimum possible localization resources: a single subcarrier and a single snapshot at each single-antenna AP. In this paper, we formulate phase-coherent frugal SLAM as a coherent imaging problem, constructing a spatial image over a region of interest by treating the distributed AP observations as coming from a large synthetic aperture. Based on the coherent image, we develop a detection and localization framework that jointly identifies the UE, reflective surfaces, and scatterers. Simulation results validate the proposed framework and provide insights into the impact of grid resolution and off-grid error on detection and localization performance.
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Submitted 15 April, 2026;
originally announced April 2026.
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Critical regularity and dissipativity for stochastic reaction-diffusion equations in Bochner spaces over spaces of continuous functions
Authors:
Xuewei Ju,
Xiaoting Tong
Abstract:
In this paper, we consider the stochastic reaction-diffusion equation $\mathrm{d}u = (\mathcal{A} u + f(u))\mathrm{d}t + σ(u)\mathrm{d}W$ on a smooth bounded domain $\mathcal{O}$ with homogeneous Dirichlet boundary conditions. We investigate the long-time behavior of solutions with a strongly dissipative drift nonlinearity and superlinear multiplicative noise in the Bochner space…
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In this paper, we consider the stochastic reaction-diffusion equation $\mathrm{d}u = (\mathcal{A} u + f(u))\mathrm{d}t + σ(u)\mathrm{d}W$ on a smooth bounded domain $\mathcal{O}$ with homogeneous Dirichlet boundary conditions. We investigate the long-time behavior of solutions with a strongly dissipative drift nonlinearity and superlinear multiplicative noise in the Bochner space $L^q(Ω; C_0(\overline{\mathcal{O}}))$, $q \ge 2$. Here $\mathcal{A}$ is a second-order self-adjoint elliptic operator and $W$ is a two-sided trace-class Wiener process. The standard Galerkin method fails to yield energy estimates in $L^q(Ω; L^q(\mathcal{O}))$ via the Itô formula for $q > 2$, owing to the interference of projection operators when dealing with nonlinear terms; meanwhile, the classical theory of mild solutions lacks sufficient spatial regularity to apply the Itô formula directly. To overcome these difficulties, we consider mild solutions and establish a critical regularity estimate for the corresponding stopped process $u_n(t)$ in $W_0^{1,q}(\mathcal{O})$, which rigorously justifies the use of the Itô formula in the non-Hilbert space $L^q(Ω; L^q(\mathcal{O}))$. As a result, we derive explicit moment energy estimates and quantitative dissipativity bounds, yielding global existence, uniqueness, and exponential asymptotic decay of solutions in $L^q(Ω; C_0(\overline{\mathcal{O}}))$. Unlike previous qualitative results in continuous function spaces, our framework provides a fully quantitative theory of global dissipativity.
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Submitted 15 April, 2026;
originally announced April 2026.
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Measurement of the $W$-boson production cross-sections in $pp$ collisions at $\sqrt{s}$ = 13 TeV in the forward region
Authors:
LHCb collaboration,
R. Aaij,
M. Abdelfatah,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis
, et al. (1112 additional authors not shown)
Abstract:
A precision measurement of the $W$-boson production cross-section is performed using the $W \to μν$ decay channel, based on a sample of proton-proton collision data collected by the LHCb experiment at $\sqrt{s}$ = 13 TeV and corresponding to an integrated luminosity of 5.1 $fb^{-1}$. The cross-section is measured for muons with transverse momentum between 25 and 55 GeV and pseudorapidity between 2…
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A precision measurement of the $W$-boson production cross-section is performed using the $W \to μν$ decay channel, based on a sample of proton-proton collision data collected by the LHCb experiment at $\sqrt{s}$ = 13 TeV and corresponding to an integrated luminosity of 5.1 $fb^{-1}$. The cross-section is measured for muons with transverse momentum between 25 and 55 GeV and pseudorapidity between 2.0 and 4.5. The integrated production cross-sections of $W$ bosons are measured to be $$ \begin{array}{lcl} σ_{W^+ \to μ^+ν} &=& 1754.2 \pm 1.5 \pm 11.9 \pm 35.1\text{ pb} \\ σ_{W^- \to μ^-\barν} &=& 1178.1 \pm 1.3 \pm 9.7 \pm 23.6\text{ pb} \end{array} $$ where uncertainties are statistical, systematic, and due to the luminosity determination, respectively. Results are in good agreement with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. This measurement is significantly more precise than previous results in this kinematic regime.
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Submitted 14 April, 2026;
originally announced April 2026.
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Precision measurement of the muon charge asymmetry from $W$-boson decays in $pp$ collisions at $\sqrt{s}$ = 13 TeV in the forward region
Authors:
LHCb collaboration,
R. Aaij,
M. Abdelfatah,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis
, et al. (1112 additional authors not shown)
Abstract:
A precision measurement of the muon charge asymmetry from $W$-boson decays in proton-proton collisions at $\sqrt{s}$ = 13 TeV is presented. The analysis utilizes data corresponding to an integrated luminosity of 5.1 $fb^{-1}$, recorded by the LHCb detector during 2016, 2017 and 2018. The asymmetry is measured for muons with transverse momentum between 25 and 55 GeV and pseudorapidity between 2.0 a…
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A precision measurement of the muon charge asymmetry from $W$-boson decays in proton-proton collisions at $\sqrt{s}$ = 13 TeV is presented. The analysis utilizes data corresponding to an integrated luminosity of 5.1 $fb^{-1}$, recorded by the LHCb detector during 2016, 2017 and 2018. The asymmetry is measured for muons with transverse momentum between 25 and 55 GeV and pseudorapidity between 2.0 and 4.5. This result represents the most precise determination of the muon charge asymmetry in the forward region to date, exhibiting excellent agreement with next-to-next-to-leading-order predictions in perturbative quantum chromodynamics.
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Submitted 14 April, 2026;
originally announced April 2026.
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Measurement of inclusive production of charmonium states in $b$-hadron decays via their decay into $φφ$
Authors:
LHCb collaboration,
R. Aaij,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis,
L. An
, et al. (1173 additional authors not shown)
Abstract:
The inclusive production of the $η_c(1S)$, $η_c(2S)$ and $χ_{c}$ charmonium states in $b$-hadron decays is studied with LHCb Run~2 data, corresponding to an integrated luminosity of $5.9~\text{fb}^{-1}$, using charmonia decays to $φφ$ pairs. The production branching fractions of the $χ_{c}(1P)$ states in $b$-hadron decays are measured, using $b \to η_c(1S) (\to φφ) X$ as a normalisation channel, w…
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The inclusive production of the $η_c(1S)$, $η_c(2S)$ and $χ_{c}$ charmonium states in $b$-hadron decays is studied with LHCb Run~2 data, corresponding to an integrated luminosity of $5.9~\text{fb}^{-1}$, using charmonia decays to $φφ$ pairs. The production branching fractions of the $χ_{c}(1P)$ states in $b$-hadron decays are measured, using $b \to η_c(1S) (\to φφ) X$ as a normalisation channel, with $X$ indicating any additional particles. The results are \begin{align*}
&{\cal{B}} (b \to χ_{c0} X) = (1.34 \pm 0.13 \pm 0.06 \pm 0.37) \times 10^{-3},
&{\cal{B}} (b \to χ_{c1} X) = (1.58 \pm 0.12 \pm 0.09 \pm 0.44) \times 10^{-3},
&{\cal{B}} (b \to χ_{c2} X) = (0.55 \pm 0.08 \pm 0.05 \pm 0.15) \times 10^{-3}, \end{align*} where the first uncertainty is statistical, the second systematic and the last is due to the limited knowledge of externally measured branching fractions. The production branching fraction of $η_c(2S)$ times the branching fraction of its decay into $φφ$ is measured as ${\cal{B}} (b \to η_c(2S) X) \times {\cal{B}} (η_c(2S) \to φφ) = (4.0 \pm 0.6 \pm 0.6 \pm 1.1) \times 10^{-7}$. Furthermore, the mass of the $η_c(1S)$ state is measured to be $M_{η_c(1S)} = 2984.1 \pm 0.5 \pm 0.5$ MeV with the best precision to date.
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Submitted 13 April, 2026;
originally announced April 2026.
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CogInstrument: Modeling Cognitive Processes for Bidirectional Human-LLM Alignment in Planning Tasks
Authors:
Anqi Wang,
Dongyijie Pan,
Xin Tong,
Pan Hui
Abstract:
Although Large Language Models (LLMs) demonstrate proficiency in knowledge-intensive tasks, current interfaces frequently precipitate cognitive misalignment by failing to externalize users' underlying reasoning structures. Existing tools typically represent intent as "flat lists," thereby disregarding the causal dependencies and revisable assumptions inherent in human decision-making. We introduce…
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Although Large Language Models (LLMs) demonstrate proficiency in knowledge-intensive tasks, current interfaces frequently precipitate cognitive misalignment by failing to externalize users' underlying reasoning structures. Existing tools typically represent intent as "flat lists," thereby disregarding the causal dependencies and revisable assumptions inherent in human decision-making. We introduce CogInstrument, a system that represents user reasoning through cognitive motifs-compositional, revisable units comprising concepts linked by causal dependencies. CogInstrument extracts these motifs from natural language interactions and renders them as editable graphical structures to facilitate bidirectional alignment. This structural externalization enables both the user and the LLM to inspect, negotiate, and reconcile reasoning processes iteratively. A within-subjects study (N=12) demonstrates that CogInstrument explicitly surfaces implicit reasoning structures, facilitating more targeted revision and reusability over conventional LLM-based dialogue interfaces. By enabling users to verify the logical grounding of LLM outputs, CogInstrument significantly enhances user agency, trust, and structural control over the collaboration. This work formalizes cognitive motifs as a fundamental unit for human-LLM alignment, providing a novel framework for achieving structured, reasoning-based human-AI collaboration.
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Submitted 12 April, 2026;
originally announced April 2026.
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NexusAI: Enabling Design Space Exploration of Ideas through Cognitive Abstraction and Functional Decomposition
Authors:
Anqi Wang,
Bingqian Wang,
Huiyang Chen,
Keqing Jiao,
Lei Han,
Xin Tong,
Pan Hui
Abstract:
Large Language Models (LLMs) offer vast potential for creative ideation; however, their standard interaction paradigm often produces unstructured textual outputs that lead users to prematurely converge on sub-optimal ideas-a phenomenon known as fixation. While recent creativity tools have begun to structure these outputs, they remain compositionally opaque: ideas are organized as monolithic units…
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Large Language Models (LLMs) offer vast potential for creative ideation; however, their standard interaction paradigm often produces unstructured textual outputs that lead users to prematurely converge on sub-optimal ideas-a phenomenon known as fixation. While recent creativity tools have begun to structure these outputs, they remain compositionally opaque: ideas are organized as monolithic units that cannot be decomposed, abstracted, or recombinable at a sub-idea level. To address this, we propose Cognitive Abstraction (CA), a computational pipeline that transforms raw LLM-generated inspiration into a navigable and transformable design space. We implement this pipeline in NexusAI, a prototype diagramming system that supports (I) decomposition of inspiration into typed functional fragments, (II) multi-level abstraction to externalize mental scaling, and (III) cross-dimensional recombination to spark novel design directions. A within-subject user study (N=14) demonstrates that NexusAI significantly improves design space exploration, reduces cognitive overhead, and facilitates perspective reframing compared to a baseline. Our work contributes: (1) a characterization of "compositional opacity" as a barrier in human-AI co-creation; (2) the CA pipeline for operationalizing creative cognitive primitives at scale; and (3) empirical evidence that structured, multi-level representations can effectively mitigate fixation and support divergent exploration.
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Submitted 12 April, 2026;
originally announced April 2026.
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Test of lepton flavour universality with $B^0\to K^{*0}\ell^+\ell^-$ decays at large dilepton invariant mass
Authors:
LHCb collaboration,
R. Aaij,
M. Abdelfatah,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis
, et al. (1113 additional authors not shown)
Abstract:
Muon-electron universality is tested in $B^0 \to K^{*0} \ \ell^+ \ell^-$ decays, in the dilepton-invariant-mass region above the $ψ(2S)$ resonance. The analysis uses beauty mesons produced in proton-proton collisions recorded by the LHCb detector at center-of-mass energies of 7, 8, and 13 $\text{TeV}$, corresponding to an integrated luminosity of 9 $\text{fb}^{-1}$. The ratio of branching fraction…
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Muon-electron universality is tested in $B^0 \to K^{*0} \ \ell^+ \ell^-$ decays, in the dilepton-invariant-mass region above the $ψ(2S)$ resonance. The analysis uses beauty mesons produced in proton-proton collisions recorded by the LHCb detector at center-of-mass energies of 7, 8, and 13 $\text{TeV}$, corresponding to an integrated luminosity of 9 $\text{fb}^{-1}$. The ratio of branching fractions between the muon and electron channels, $R_{K^{*0}}$, is measured to be $1.08\,^{+0.14}_{-0.12}\text{(stat)} \ \pm 0.07\text{(syst)}$ for a dilepton-invariant-mass squared above 14.0 $\text{GeV}^{2}/\text{c}^{4}$, consistent with the Standard Model prediction. This result represents the most precise measurement of $R_{K^{*0}}$ in this region and the first such measurement performed at a hadron collider.
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Submitted 9 April, 2026;
originally announced April 2026.
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Search for the lepton-flavour violating decays $B^+ \to π^+ μ^\pm e^\mp$
Authors:
LHCb collaboration,
R. Aaij,
M. Abdelfatah,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
S. Amato,
J. L. Amey,
Y. Amhis,
L. An,
L. Anderlini
, et al. (1105 additional authors not shown)
Abstract:
The first search for the lepton-flavour violating decays $B^+ \to π^+ μ^{\pm} e^{\mp}$ in proton-proton collisions is presented, using data collected by the LHCb experiment between 2011 and 2018, corresponding to an integrated luminosity of 9 fb$^{-1}$. No significant signal is observed and an upper limit on the branching fraction is set at…
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The first search for the lepton-flavour violating decays $B^+ \to π^+ μ^{\pm} e^{\mp}$ in proton-proton collisions is presented, using data collected by the LHCb experiment between 2011 and 2018, corresponding to an integrated luminosity of 9 fb$^{-1}$. No significant signal is observed and an upper limit on the branching fraction is set at $\mathcal{B}(B^+ \to π^+ μ^{\pm} e^{\mp}) < 1.8 \times 10^{-9}$ at the $90\%$ confidence level, two orders of magnitude more restrictive than the current world average. This is the first constraint on lepton-flavour violating $b \to d$ quark transitions at the LHC and also sets the most stringent upper limits to date on $b \to d μ^{\pm} e^{\mp}$ transitions. Limits on left-handed and scalar scenarios beyond the Standard Model are also reported.
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Submitted 9 April, 2026;
originally announced April 2026.
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LPM 1.0: Video-based Character Performance Model
Authors:
Ailing Zeng,
Casper Yang,
Chauncey Ge,
Eddie Zhang,
Garvey Xu,
Gavin Lin,
Gilbert Gu,
Jeremy Pi,
Leo Li,
Mingyi Shi,
Shawn Wang,
Sheng Bi,
Steven Tang,
Thorn Hang,
Tobey Guo,
Vincent Li,
Xin Tong,
Yikang Li,
Yuchen Sun,
Yue Zhao,
Yuhan Lu,
Yuwei Li,
Zane Zhang,
Zeshi Yang,
Zi Ye
Abstract:
Performance, the externalization of intent, emotion, and personality through visual, vocal, and temporal behavior, is what makes a character alive. Learning such performance from video is a promising alternative to traditional 3D pipelines. However, existing video models struggle to jointly achieve high expressiveness, real-time inference, and long-horizon identity stability, a tension we call the…
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Performance, the externalization of intent, emotion, and personality through visual, vocal, and temporal behavior, is what makes a character alive. Learning such performance from video is a promising alternative to traditional 3D pipelines. However, existing video models struggle to jointly achieve high expressiveness, real-time inference, and long-horizon identity stability, a tension we call the performance trilemma. Conversation is the most comprehensive performance scenario, as characters simultaneously speak, listen, react, and emote while maintaining identity over time. To address this, we present LPM 1.0 (Large Performance Model), focusing on single-person full-duplex audio-visual conversational performance. Concretely, we build a multimodal human-centric dataset through strict filtering, speaking-listening audio-video pairing, performance understanding, and identity-aware multi-reference extraction; train a 17B-parameter Diffusion Transformer (Base LPM) for highly controllable, identity-consistent performance through multimodal conditioning; and distill it into a causal streaming generator (Online LPM) for low-latency, infinite-length interaction. At inference, given a character image with identity-aware references, LPM 1.0 generates listening videos from user audio and speaking videos from synthesized audio, with text prompts for motion control, all at real-time speed with identity-stable, infinite-length generation. LPM 1.0 thus serves as a visual engine for conversational agents, live streaming characters, and game NPCs. To systematically evaluate this setting, we propose LPM-Bench, the first benchmark for interactive character performance. LPM 1.0 achieves state-of-the-art results across all evaluated dimensions while maintaining real-time inference.
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Submitted 14 April, 2026; v1 submitted 9 April, 2026;
originally announced April 2026.
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Precise measurement of the CKM angle $γ$ with a novel approach
Authors:
The BESIII,
LHCb Collaborations,
:,
M. Ablikim,
M. N. Achasov,
P. Adlarson,
X. C. Ai,
C. S. Akondi,
R. Aliberti,
A. Amoroso,
Q. An,
Y. H. An,
Y. Bai,
O. Bakina,
H. R. Bao,
X. L. Bao,
M. Barbagiovanni,
V. Batozskaya,
K. Begzsuren,
N. Berger,
M. Berlowski,
M. B. Bertani,
D. Bettoni,
F. Bianchi,
E. Bianco
, et al. (1936 additional authors not shown)
Abstract:
A measurement of the CKM angle $γ$ is performed by applying a novel, unbinned, model-independent approach to datasets of electron-positron collisions collected by the BESIII experiment and proton-proton collisions by the LHCb experiment, corresponding to integrated luminosities of 8 fb$^{-1}$ and 9 fb$^{-1}$, respectively. The $C\!P$-violating phase $γ$ is determined from…
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A measurement of the CKM angle $γ$ is performed by applying a novel, unbinned, model-independent approach to datasets of electron-positron collisions collected by the BESIII experiment and proton-proton collisions by the LHCb experiment, corresponding to integrated luminosities of 8 fb$^{-1}$ and 9 fb$^{-1}$, respectively. The $C\!P$-violating phase $γ$ is determined from ${B^{\pm}\rightarrow D(\rightarrow K_{\rm S}^{0} h^{\prime+}h^{\prime-}) h^{\pm}}$ decays in LHCb data, where $h^{(\prime)}$ is either a pion or kaon, while the corresponding strong-phase parameters are measured using doubly tagged ${D\rightarrow K_{\rm S/L}^0 h^{\prime+} h^{\prime-}}$ decays in the quantum-correlated $D\overline{D}$ system present in BESIII data. A joint fit to both datasets, which allows for a simultaneous determination of the associated $C\!P$-violating observables and strong-phase parameters, yields ${γ= (71.3\pm 5.0)^{\circ}}$. The result is the most precise to date and consistent with previous measurements and world averages.
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Submitted 7 April, 2026;
originally announced April 2026.
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Measurement of the CKM angle $γ$ in $B^{\pm} \rightarrow D(\rightarrow K^{0}_{\rm S} h^{\prime+}h^{\prime-})h^{\pm}$ decays with a novel approach
Authors:
The BESIII,
LHCb Collaborations,
:,
M. Ablikim,
M. N. Achasov,
P. Adlarson,
X. C. Ai,
C. S. Akondi,
R. Aliberti,
A. Amoroso,
Q. An,
Y. H. An,
Y. Bai,
O. Bakina,
H. R. Bao,
X. L. Bao,
M. Barbagiovanni,
V. Batozskaya,
K. Begzsuren,
N. Berger,
M. Berlowski,
M. B. Bertani,
D. Bettoni,
F. Bianchi,
E. Bianco
, et al. (1936 additional authors not shown)
Abstract:
A measurement of the CKM angle $γ$ and related strong-phase parameters is performed using a novel, model-independent approach in ${B^{\pm}\rightarrow D(\rightarrow K^{0}_{\rm S} h^{\prime+}h^{\prime-}) h^{\pm}}$ decays, where $h^{(\prime)} \equiv π, K$. The analysis uses a joint data sample of electron-positron collisions collected by the BESIII experiment at the Beijing Electron-Positron Collider…
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A measurement of the CKM angle $γ$ and related strong-phase parameters is performed using a novel, model-independent approach in ${B^{\pm}\rightarrow D(\rightarrow K^{0}_{\rm S} h^{\prime+}h^{\prime-}) h^{\pm}}$ decays, where $h^{(\prime)} \equiv π, K$. The analysis uses a joint data sample of electron-positron collisions collected by the BESIII experiment at the Beijing Electron-Positron Collider II during 2010--2011 and 2021--2022, corresponding to an integrated luminosity of 8 fb$^{-1}$, and proton-proton collisions collected by the LHCb experiment at the Large Hadron Collider during 2011--2018, corresponding to an integrated luminosity of 9 fb$^{-1}$. The two datasets are analyzed simultaneously by applying per-event weights based on the amplitude variation over the $D$-decay phase space to enhance the sensitivity to $C\!P$-violating observables. The CKM angle $γ$ is determined to be $γ= (71.3\pm 5.0)^{\circ}$, which constitutes the most precise single measurement to date.
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Submitted 7 April, 2026;
originally announced April 2026.
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Search for the decays $B_{(s)}^0\to J/ψγ$ at LHCb
Authors:
LHCb collaboration,
R. Aaij,
M. Abdelfatah,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis
, et al. (1114 additional authors not shown)
Abstract:
A search for the rare decays $B_{(s)}^0\to J/ψγ$ is performed with proton-proton collision data collected by the LHCb experiment, corresponding to integrated luminosities of $3~\rm{fb}^{-1}$ at centre-of-mass energies of 7 and 8 TeV, and $6~\rm{fb}^{-1}$ at 13 TeV. Assuming no contribution from $B^0\to J/ψγ$ decay, an upper limit is set on the branching fraction…
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A search for the rare decays $B_{(s)}^0\to J/ψγ$ is performed with proton-proton collision data collected by the LHCb experiment, corresponding to integrated luminosities of $3~\rm{fb}^{-1}$ at centre-of-mass energies of 7 and 8 TeV, and $6~\rm{fb}^{-1}$ at 13 TeV. Assuming no contribution from $B^0\to J/ψγ$ decay, an upper limit is set on the branching fraction $\mathcal{B}(B_{s}^0\to J/ψγ)<2.9\times10^{-6}$ at the 90% confidence level. If instead no contribution from $B_{s}^0\to J/ψγ$ decay is assumed, the limit is $\mathcal{B}(B^0\to J/ψγ)<2.5\times10^{-6}$ at the 90% confidence level. These results supersede the previous LHCb results, with the limit for $B_{s}^0\to J/ψγ$ improved by a factor of 2.5.
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Submitted 3 April, 2026;
originally announced April 2026.
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Horizontal-Component Prior-based Framework for Adaptive Shear-wave Leakage Suppression in OBC Data
Authors:
Zheng Cong,
Shiqi Dong,
Xintong Dong,
Xunqian Tong
Abstract:
Shear-wave leakage in the vertical (Z) component of ocean-bottom cable (OBC) seismic data commonly results from the receiver tilt and poor seafloor coupling, introducing unwanted coherent noise that impacts the subsequent data processing and imaging. Traditional denoising methods are limited by manual parameter tuning and idealized model assumptions, while deep-learning (DL) approaches have shown…
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Shear-wave leakage in the vertical (Z) component of ocean-bottom cable (OBC) seismic data commonly results from the receiver tilt and poor seafloor coupling, introducing unwanted coherent noise that impacts the subsequent data processing and imaging. Traditional denoising methods are limited by manual parameter tuning and idealized model assumptions, while deep-learning (DL) approaches have shown significant potential in suppressing shear-wave leakage. However, supervised learning requires clean primary waves (P waves) as the label, which is generally impractical to obtain for field data. To address these challenges, we propose a framework based on horizontal-component priors for adaptive shear-wave leakage suppression (HPAS). Instead of relying on clean primary-wave (P-wave) data, HPAS generates input-label pairs directly from raw multi-component field data using an additive-subtractive noise strategy. Specifically, we extract shear-wave (S-wave) noise from the horizontal components and apply a linear transformation to match its first and second order moments with the S-wave leakage in the Z-component, and the statistically matched noise is then added to and subtracted from the original Z-component to create the input and label pairs. By allowing the denoising model to learn the S-wave features present in the differences between the input and the label, the adaptive denoising process approximates supervised learning. Evaluations on both synthetic and field data demonstrate that the proposed HPAS framework effectively and adaptively suppresses S-wave leakage while preserving the amplitude of the P-wave signals in the Z-component, offering a robust solution with strong generalization capabilities.
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Submitted 7 April, 2026; v1 submitted 1 April, 2026;
originally announced April 2026.
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Observation of the doubly charmed baryon $\itΞ_{cc}^+$ with the LHCb Run 3 detector
Authors:
LHCb collaboration,
R. Aaij,
M. Abdelfatah,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
S. Amato,
J. L. Amey,
Y. Amhis,
L. An,
L. Anderlini
, et al. (1107 additional authors not shown)
Abstract:
The first observation of the doubly charmed baryon $\itΞ_{cc}^+$ is reported through its decay to the $\itΛ_c^+ K^-π^+$ final state, with a statistical significance exceeding seven standard deviations. The observation is made using proton-proton collision data collected in 2024 with the LHCb Run 3 detector at a center-of-mass energy of 13.6 TeV, corresponding to a total integrated luminosity of…
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The first observation of the doubly charmed baryon $\itΞ_{cc}^+$ is reported through its decay to the $\itΛ_c^+ K^-π^+$ final state, with a statistical significance exceeding seven standard deviations. The observation is made using proton-proton collision data collected in 2024 with the LHCb Run 3 detector at a center-of-mass energy of 13.6 TeV, corresponding to a total integrated luminosity of $6.9\,\mathrm{fb}^{-1}$. The $\itΞ_{cc}^+$ mass is measured to be $3619.97 \pm 0.83 \pm 0.26 \,^{+1.90}_{-1.30}\,\mathrm{MeV}/c^2$, where the first uncertainty is statistical, the second is systematic, and the third is due to the unknown $\itΞ_{cc}^+$ lifetime, which is assumed to lie in the range 15-160 fs with a baseline value of 45 fs. The difference between the masses of the $\itΞ_{cc}^+$ and $\itΞ_{cc}^{++}$ baryons is determined to be $-1.77 \pm 0.84 \pm 0.15 \,^{+1.90}_{-1.30}\,\mathrm{MeV}/c^2$. This is the first observation of a new particle made with the LHCb Run 3 detector.
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Submitted 30 March, 2026;
originally announced March 2026.
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Measurement of CP asymmetries in $\kern 0.18em\overline{\kern -0.18em B}^0 \to D_s^- D^+$ and $\kern 0.18em\overline{\kern -0.18em B}_s^0 \to D_s^+ D^-$ decays
Authors:
LHCb collaboration,
R. Aaij,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
M. Akthar,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis
, et al. (1188 additional authors not shown)
Abstract:
Measurements of the combined CP asymmetries in $\kern 0.18em\overline{\kern -0.18em B}^0 \to D_s^- D^+$ and $\kern 0.18em\overline{\kern -0.18em B}_s^0 \to D_s^+ D^-$ decays are made using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9fb$^{-1}$. The measurements are found to be \begin{aligned} A_{CP}(\kern 0.18em\overline{\kern -0.18em…
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Measurements of the combined CP asymmetries in $\kern 0.18em\overline{\kern -0.18em B}^0 \to D_s^- D^+$ and $\kern 0.18em\overline{\kern -0.18em B}_s^0 \to D_s^+ D^-$ decays are made using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9fb$^{-1}$. The measurements are found to be \begin{aligned} A_{CP}(\kern 0.18em\overline{\kern -0.18em B}^0 \to D_s^- D^+) &= 0.0009 \pm 0.0053 \pm 0.0040, \\ A_{CP}(\kern 0.18em\overline{\kern -0.18em B}_s^0 \to D_s^+ D^-) &= 0.103\phantom{0} \pm 0.053\phantom{0} \pm 0.010, \end{aligned} where the first and second uncertainties are statistical and systematic, respectively. This is the first measurement of this asymmetry in $\kern 0.18em\overline{\kern -0.18em B}_s^0$ decays, and the most precise measurement to date for $\kern 0.18em\overline{\kern -0.18em B}^0$ decays. Both measurements are found to be consistent with CP symmetry.
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Submitted 30 March, 2026;
originally announced March 2026.
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$B$-jet fragmentation with $B^{\pm} \to J/ψK^{\pm}$ decays in $\sqrt{s} = 13$ TeV $pp$ collisions at LHCb
Authors:
LHCb collaboration,
R. Aaij,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis,
L. An
, et al. (1164 additional authors not shown)
Abstract:
The collinear and transverse-momentum-dependent jet fragmentation function and the radial profile for $B^{\pm}$ mesons in jets are measured. The $B^{\pm}$ mesons are reconstructed through the $J/ψ(\to μ^{+} μ^{-}) K^{\pm}$ decay channel using proton-proton collision data collected during 2016-2018 with the LHCb detector at a center-of-mass energy of $\sqrt{s}=13$ TeV, corresponding to an integrate…
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The collinear and transverse-momentum-dependent jet fragmentation function and the radial profile for $B^{\pm}$ mesons in jets are measured. The $B^{\pm}$ mesons are reconstructed through the $J/ψ(\to μ^{+} μ^{-}) K^{\pm}$ decay channel using proton-proton collision data collected during 2016-2018 with the LHCb detector at a center-of-mass energy of $\sqrt{s}=13$ TeV, corresponding to an integrated luminosity of $5.4$ fb$^{-1}$. The results complement recent measurements of jet fragmentation functions for heavy-flavor hadrons and suggest a growing contribution of gluon fragmentation to $B^{\pm}$ mesons as the jet transverse momentum increases.
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Submitted 24 March, 2026;
originally announced March 2026.
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Non-Hermitian Mosaic Maryland model
Authors:
Zhenning Wang,
Ni Lu,
Dan Liu,
Xiaosen Yang,
Xianqi Tong
Abstract:
We introduce the non-Hermitian mosaic Maryland model, where a discrete modulation period and a non-Hermitian phase are incorporated into the potential, rendering the originally exactly solvable system generally non-integrable. This model provides a unique platform to investigate how structural modulation governs localization in complex quasiperiodic potentials. Using Avila's global theory, we anal…
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We introduce the non-Hermitian mosaic Maryland model, where a discrete modulation period and a non-Hermitian phase are incorporated into the potential, rendering the originally exactly solvable system generally non-integrable. This model provides a unique platform to investigate how structural modulation governs localization in complex quasiperiodic potentials. Using Avila's global theory, we analytically derive the exact Lyapunov exponent and obtain explicit formulas for the complex mobility edges. Remarkably, for modulation periods kappa >= 2, the system intrinsically hosts kappa-1 robust extended bands that persist independently of the potential strength and non-Hermiticity. We further characterize the topological nature of these phases via the spectral winding number. Unlike the standard Maryland model, the mosaic modulation induces mobility edges, and the resulting phase transitions are continuous, reflecting the non-integrable nature of the system. Numerical calculations of the inverse participation ratio and fractal dimension confirm the analytical predictions for the asymptotic form of the mobility edges in the large non-Hermiticity limit. This work establishes structural design as a powerful degree of freedom for engineering wave transport and enhancing the robustness of extended states in non-Hermitian systems.
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Submitted 25 March, 2026; v1 submitted 23 March, 2026;
originally announced March 2026.
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Demonstrations, CoT, and Prompting: A Theoretical Analysis of ICL
Authors:
Xuhan Tong,
Yuchen Zeng,
Jiawei Zhang
Abstract:
In-Context Learning (ICL) enables pretrained LLMs to adapt to downstream tasks by conditioning on a small set of input-output demonstrations, without any parameter updates. Although there have been many theoretical efforts to explain how ICL works, most either rely on strong architectural or data assumptions, or fail to capture the impact of key practical factors such as demonstration selection, C…
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In-Context Learning (ICL) enables pretrained LLMs to adapt to downstream tasks by conditioning on a small set of input-output demonstrations, without any parameter updates. Although there have been many theoretical efforts to explain how ICL works, most either rely on strong architectural or data assumptions, or fail to capture the impact of key practical factors such as demonstration selection, Chain-of-Thought (CoT) prompting, the number of demonstrations, and prompt templates. We address this gap by establishing a theoretical analysis of ICL under mild assumptions that links these design choices to generalization behavior. We derive an upper bound on the ICL test loss, showing that performance is governed by (i) the quality of selected demonstrations, quantified by Lipschitz constants of the ICL loss along paths connecting test prompts to pretraining samples, (ii) an intrinsic ICL capability of the pretrained model, and (iii) the degree of distribution shift. Within the same framework, we analyze CoT prompting as inducing a task decomposition and show that it is beneficial when demonstrations are well chosen at each substep and the resulting subtasks are easier to learn. Finally, we characterize how ICL performance sensitivity to prompt templates varies with the number of demonstrations. Together, our study shows that pretraining equips the model with the ability to generalize beyond observed tasks, while CoT enables the model to compose simpler subtasks into more complex ones, and demonstrations and instructions enable it to retrieve similar or complex tasks, including those that can be composed into more complex ones, jointly supporting generalization to unseen tasks. All theoretical insights are corroborated by experiments.
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Submitted 19 March, 2026;
originally announced March 2026.
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NLOS-Aided Joint OTA Synchronization and Off-Grid Imaging for Distributed MIMO Systems
Authors:
Xin Tong,
Lechen Zhang,
Yu Ge,
Dario Tagliaferri,
Henk Wymeersch
Abstract:
Distributed multiple-input multiple-output (MIMO) architectures enable large-scale integrated sensing and communication (ISAC) by providing high spatial resolution and robustness through spatial diversity. However, practical phase-coherent sensing is challenged by phase synchronization errors and modeling mismatch caused by grid discretization. Existing over-the-air (OTA) synchronization methods t…
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Distributed multiple-input multiple-output (MIMO) architectures enable large-scale integrated sensing and communication (ISAC) by providing high spatial resolution and robustness through spatial diversity. However, practical phase-coherent sensing is challenged by phase synchronization errors and modeling mismatch caused by grid discretization. Existing over-the-air (OTA) synchronization methods typically treat synchronization and sensing tasks separately, which may lead to inaccurate phase alignment when multipath components are used for imaging. In this paper, we propose a non-line-of-sight (NLOS)-aided joint OTA synchronization and off-grid imaging framework for distributed MIMO ISAC systems. First, a line-of-sight (LOS)-assisted coarse synchronization is performed to establish initial phase coherence across distributed links. Subsequently, an iterative refinement stage exploits reconstructed NLOS components obtained from imaging results. By modeling off-grid effects via a first-order Taylor expansion, we transform measurements with nonlinear off-grid offset into an augmented linear model with jointly sparse reflectivity and off-set variables. The imaging problem is reformulated as a structured sparse recovery task and solved using a tailored off-grid approximate message passing (OG-AMP) algorithm. The imaging and synchronization modules are coupled within a closed-loop alternative optimization framework, where improved imaging enables more accurate phase refinement, and vice versa. Numerical results show that the proposed framework achieves accurate synchronization and imaging under phase errors. Compared with conventional approaches, it shows superior robustness and accuracy.
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Submitted 14 March, 2026;
originally announced March 2026.
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First measurement of time-dependent $CP$ violation in the flavor-changing neutral-current decay $B^{0}\rightarrow K_{S}^{0}μ^{+}μ^{-}$
Authors:
LHCb collaboration,
R. Aaij,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis,
L. An
, et al. (1163 additional authors not shown)
Abstract:
A flavor-tagged time-dependent analysis of $B^{0}\rightarrow K_{S}^{0}μ^{+}μ^{-}$ decays is performed across the full dimuon mass range excluding the $J/ψ$ and $ψ(2S)$ resonance regions. The analysis uses proton-proton collision data collected by the LHCb experiment in 2011--2018 at center-of-mass energies of 7, 8 and 13TeV, corresponding to an integrated luminosity of 9$fb^{-1}$. The CP violation…
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A flavor-tagged time-dependent analysis of $B^{0}\rightarrow K_{S}^{0}μ^{+}μ^{-}$ decays is performed across the full dimuon mass range excluding the $J/ψ$ and $ψ(2S)$ resonance regions. The analysis uses proton-proton collision data collected by the LHCb experiment in 2011--2018 at center-of-mass energies of 7, 8 and 13TeV, corresponding to an integrated luminosity of 9$fb^{-1}$. The CP violation parameters are determined to be $C=-0.13 \pm 0.32 \pm 0.04$ and $S= +0.82\pm 0.29 \pm 0.05$, where the first uncertainties are statistical and the second are systematic. The results are consistent with the Standard Model prediction. This is the first experimental study of time-dependent CP violation in $b\rightarrow sl^{+}l^{-}$ processes.
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Submitted 17 March, 2026; v1 submitted 13 March, 2026;
originally announced March 2026.
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Measurement of the local and nonlocal amplitudes in $B^{+}\to K^{+}μ^{+}μ^{-}$ decays
Authors:
LHCb collaboration,
R. Aaij,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis,
L. An
, et al. (1184 additional authors not shown)
Abstract:
This paper presents a thorough study of the local and nonlocal amplitudes in $B^+ \to K^+μ^+μ^-$ transitions through an amplitude analysis of the dimuon mass spectrum of the decay. The analysis is based on $pp$ collision data corresponding to an integrated luminosity of 8.4fb$^{-1}$ collected by the LHCb experiment. This measurement employs a model that describes both one-particle and two-particle…
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This paper presents a thorough study of the local and nonlocal amplitudes in $B^+ \to K^+μ^+μ^-$ transitions through an amplitude analysis of the dimuon mass spectrum of the decay. The analysis is based on $pp$ collision data corresponding to an integrated luminosity of 8.4fb$^{-1}$ collected by the LHCb experiment. This measurement employs a model that describes both one-particle and two-particle nonlocal amplitudes across the entirety of the dimuon mass spectrum, enabling the determination of both short- and long-distance contributions to the decay. The compatibility of the Wilson coefficient combinations $C_9+C_9'$ and $C_{10}+C_{10}'$ with the Standard Model prediction is found to vary between $1.6\,σ$ and $4\,σ$, depending on the choice of local form factors.
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Submitted 12 March, 2026;
originally announced March 2026.
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From Pets to Robots: MojiKit as a Data-Informed Toolkit for Affective HRI Design
Authors:
Liwen He,
Pingting Chen,
Ziheng Tang,
Yixiao Liu,
Jihong Jeung,
Teng Han,
Xin Tong
Abstract:
Designing affective behaviors for animal-inspired social robots often relies on intuition and personal experience, leading to fragmented outcomes. To provide more systematic guidance, we first coded and analyzed human-pet interaction videos, validated insights through literature and interviews, and created structured reference cards that map the design space of pet-inspired affective interactions.…
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Designing affective behaviors for animal-inspired social robots often relies on intuition and personal experience, leading to fragmented outcomes. To provide more systematic guidance, we first coded and analyzed human-pet interaction videos, validated insights through literature and interviews, and created structured reference cards that map the design space of pet-inspired affective interactions. Building on this, we developed MojiKit, a toolkit combining reference cards, a zoomorphic robot prototype (MomoBot), and a behavior control studio. We evaluated MojiKit in co-creation workshops with 18 participants, finding that MojiKit helped them design 35 affective interaction patterns beyond their own pet experiences, while the code-free studio lowered the technical barrier and enhanced creative agency. Our contributions include the data-informed structured resource for pet-inspired affective HRI design, an integrated toolkit that bridges reference materials with hands-on prototyping, and empirical evidence showing how MojiKit empowers users to systematically create richer, more diverse affective robot behaviors.
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Submitted 12 March, 2026;
originally announced March 2026.
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Electronic Coherence Evolution at the Nearly Commensurate Incommensurate CDW Boundary of 1T-TaS2
Authors:
Turgut Yilmaz,
Yi Sheng Ng,
Menka Jain,
Xiao Tong,
Thipusa Wongpinij,
Pat Photongkam,
Anil Rajapitamahuni,
Asish K. Kundu,
Jin-Cheng Zheng,
Elio Vescovo
Abstract:
Transition metal dichalcogenides host a variety of charge density wave phases that couple lattice, charge, and correlation effects. In 1T-TaS2, the commensurate and nearly commensurate states are well characterized, yet the transition near 350 K into the incommensurate phase has lacked direct momentum resolved insight. Here we use temperature dependent angle resolved photoemission spectroscopy to…
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Transition metal dichalcogenides host a variety of charge density wave phases that couple lattice, charge, and correlation effects. In 1T-TaS2, the commensurate and nearly commensurate states are well characterized, yet the transition near 350 K into the incommensurate phase has lacked direct momentum resolved insight. Here we use temperature dependent angle resolved photoemission spectroscopy to track the electronic structure across this transition. We observe a suppression of quasiparticle spectral weight at the Brillouin zone center, coincident with the transport anomaly, but without clear evidence of a full band gap opening. The transition appears to involve momentum dependent redistribution of spectral weight, consistent with a loss of coherence that reshapes the Fermi surface while leaving conduction dispersions largely intact. These results suggest that the nearly commensurate incommensurate transition may not align with a conventional metal insulator transition picture, but rather as an electronic reconstruction driven by loss of coherence. Our work provides new microscopic insight into the resistivity anomaly near room temperature and may guide design principles for collective electronic switching in Transition metal dichalcogenides.
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Submitted 11 March, 2026;
originally announced March 2026.
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First measurement of the decay-time-integrated $C\!P$ asymmetry in $B_s^0 \to D_s^- π^+$ decays
Authors:
LHCb collaboration,
R. Aaij,
M. Abdelfatah,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis
, et al. (1112 additional authors not shown)
Abstract:
A measurement of the flavour-untagged decay-time-integrated ${C\!P}$ asymmetry in the flavour-specific decay ${B_s^0 \to D_s^-π^+}$, ${\langle A^s_{\rm untagged}\rangle}$, is performed using proton-proton collision data collected by the LHCb experiment between 2016 and 2018 at a center-of-mass energy of ${13\,{\rm TeV}}$, corresponding to a total integrated luminosity of ${5.4\,{\rm fb}^{-1}}$. Th…
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A measurement of the flavour-untagged decay-time-integrated ${C\!P}$ asymmetry in the flavour-specific decay ${B_s^0 \to D_s^-π^+}$, ${\langle A^s_{\rm untagged}\rangle}$, is performed using proton-proton collision data collected by the LHCb experiment between 2016 and 2018 at a center-of-mass energy of ${13\,{\rm TeV}}$, corresponding to a total integrated luminosity of ${5.4\,{\rm fb}^{-1}}$. The ${C\!P}$ asymmetry is measured in two $D_s^-$ meson decay modes, ${D_s^- \to K^-K^+π^-}$ and ${D_s^- \to π^-π^+π^-}$. The combined result, $\langle A^s_{\rm untagged}\rangle = ( -1.4 \pm 5.9\,\rm{(stat)} \pm 1.1\,\rm{(syst)}) \times 10^{-3}$, is consistent with the Standard Model expectation and provides a direct constraint on new physics in tree-level $b$-hadron decays.
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Submitted 17 March, 2026; v1 submitted 11 March, 2026;
originally announced March 2026.
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CLoE: Expert Consistency Learning for Missing Modality Segmentation
Authors:
Xinyu Tong,
Meihua Zhou,
Bowu Fan,
Haitao Li
Abstract:
Multimodal medical image segmentation often faces missing modalities at inference, which induces disagreement among modality experts and makes fusion unstable, particularly on small foreground structures. We propose Consistency Learning of Experts (CLoE), a consistency-driven framework for missing-modality segmentation that preserves strong performance when all modalities are available. CLoE formu…
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Multimodal medical image segmentation often faces missing modalities at inference, which induces disagreement among modality experts and makes fusion unstable, particularly on small foreground structures. We propose Consistency Learning of Experts (CLoE), a consistency-driven framework for missing-modality segmentation that preserves strong performance when all modalities are available. CLoE formulates robustness as decision-level expert consistency control and introduces a dual-branch Expert Consistency Learning objective. Modality Expert Consistency enforces global agreement among expert predictions to reduce case-wise drift under partial inputs, while Region Expert Consistency emphasizes agreement on clinically critical foreground regions to avoid background-dominated regularization. We further map consistency scores to modality reliability weights using a lightweight gating network, enabling reliability-aware feature recalibration before fusion. Extensive experiments on BraTS 2020 and MSD Prostate demonstrate that CLoE outperforms state-of-the-art methods in incomplete multimodal segmentation, while exhibiting strong cross-dataset generalization and improving robustness on clinically critical structures.
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Submitted 10 March, 2026;
originally announced March 2026.
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All-Loop Renormalization and the Phase of the de Sitter Wavefunction
Authors:
Alexander Farren,
Ciaran McCulloch,
Enrico Pajer,
Xi Tong
Abstract:
Cosmological observables of the primordial universe are encoded in the late-time field-theoretic wavefunction. For shift-symmetric scalars in de Sitter, a good approximation for many inflationary models, the wavefunction must be purely real at tree-level. This property is violated by a quantum anomaly in the process of renormalization. As a result, we show that the imaginary part of the wavefuncti…
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Cosmological observables of the primordial universe are encoded in the late-time field-theoretic wavefunction. For shift-symmetric scalars in de Sitter, a good approximation for many inflationary models, the wavefunction must be purely real at tree-level. This property is violated by a quantum anomaly in the process of renormalization. As a result, we show that the imaginary part of the wavefunction is fixed by its dependence on the renormalization scale to all loop orders in perturbation theory. This follows from unitarity, locality, dilation isometry and a Bunch-Davies state. The compact relation we uncover for the wavefunction implies an infinite set of relations among correlators of massless fields and their conjugate momenta, which we exemplify at one-loop order.
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Submitted 9 March, 2026;
originally announced March 2026.
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Improved branching-fraction measurements of $B^0_{(s)} \to K_S^0 h^+ h^{'-}$ decays and first observation of $B^0_{s} \to K_S^0 K^+ K^-$
Authors:
LHCb collaboration,
R. Aaij,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
H. Afsharnia,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
F. Alessio,
Z. Aliouche,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis
, et al. (1118 additional authors not shown)
Abstract:
This paper presents a study of the charmless three-body decays ${B^0_{(s)} \to K_{\mathrm{S}}^0 h^+ h^{\prime -}}$ (where $h^{(\prime)} = π, K$), using a sample of $pp$ collision data collected by the LHCb experiment, corresponding to an integrated luminosity of $9\mbox{\,fb}^{-1}$. The decay ${B^0_s \to K_{\mathrm{S}}^0 K^+ K^-}$ is observed for the first time, and the following ratios of branchi…
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This paper presents a study of the charmless three-body decays ${B^0_{(s)} \to K_{\mathrm{S}}^0 h^+ h^{\prime -}}$ (where $h^{(\prime)} = π, K$), using a sample of $pp$ collision data collected by the LHCb experiment, corresponding to an integrated luminosity of $9\mbox{\,fb}^{-1}$. The decay ${B^0_s \to K_{\mathrm{S}}^0 K^+ K^-}$ is observed for the first time, and the following ratios of branching fractions are measured: \begin{alignat*}{6}
&\frac{{\cal B}(B^0 \to K^0_{\mathrm{S}} K^+ K^-)}{{\cal B}(B^0 \to K^0_{\mathrm{S}} π^+π^-)} &&= 0.578 &&\pm 0.007 &&\pm 0.017\,,
&\frac{{\cal B}(B^0 \to K^0_{\mathrm{S}} K^\pmπ^\mp)}{{\cal B}(B^0 \to K^0_{\mathrm{S}} π^+π^-)} &&= 0.1363 &&\pm 0.0035 &&\pm 0.0051\,,
&\frac{{\cal B}(B^0_s \to K^0_{\mathrm{S}} π^+π^-)}{{\cal B}(B^0 \to K^0_{\mathrm{S}} π^+π^-)} &&= 0.269 &&\pm 0.011 &&\pm 0.015 && \pm 0.008\,,
&\frac{{\cal B}(B^0_s \to K^0_{\mathrm{S}} K^+ K^-)}{{\cal B}(B^0 \to K^0_{\mathrm{S}} π^+π^-)} &&= 0.0303 &&\pm 0.0041 &&\pm 0.0025 && \pm 0.0009\,,
&\frac{{\cal B}(B^0_s \to K^0_{\mathrm{S}} K^\pmπ^\mp)}{{\cal B}(B^0 \to K^0_{\mathrm{S}} π^+π^-)} &&= 1.818 &&\pm 0.021 &&\pm 0.031 && \pm 0.056\,, \end{alignat*} where the uncertainties are statistical, systematic, and due to knowledge of the ratio of hadronisation fractions of the $B^0_s$ and $B^0$ mesons, respectively.
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Submitted 9 March, 2026;
originally announced March 2026.
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Disentangled Textual Priors for Diffusion-based Image Super-Resolution
Authors:
Lei Jiang,
Xin Liu,
Xinze Tong,
Zhiliang Li,
Jie Liu,
Jie Tang,
Gangshan Wu
Abstract:
Image Super-Resolution (SR) aims to reconstruct high-resolution images from degraded low-resolution inputs. While diffusion-based SR methods offer powerful generative capabilities, their performance heavily depends on how semantic priors are structured and integrated into the generation process. Existing approaches often rely on entangled or coarse-grained priors that mix global layout with local…
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Image Super-Resolution (SR) aims to reconstruct high-resolution images from degraded low-resolution inputs. While diffusion-based SR methods offer powerful generative capabilities, their performance heavily depends on how semantic priors are structured and integrated into the generation process. Existing approaches often rely on entangled or coarse-grained priors that mix global layout with local details, or conflate structural and textural cues, thereby limiting semantic controllability and interpretability. In this work, we propose DTPSR, a novel diffusion-based SR framework that introduces disentangled textual priors along two complementary dimensions: spatial hierarchy (global vs. local) and frequency semantics (low- vs. high-frequency). By explicitly separating these priors, DTPSR enables the model to simultaneously capture scene-level structure and object-specific details with frequency-aware semantic guidance. The corresponding embeddings are injected via specialized cross-attention modules, forming a progressive generation pipeline that reflects the semantic granularity of visual content, from global layout to fine-grained textures. To support this paradigm, we construct DisText-SR, a large-scale dataset containing approximately 95,000 image-text pairs with carefully disentangled global, low-frequency, and high-frequency descriptions. To further enhance controllability and consistency, we adopt a multi-branch classifier-free guidance strategy with frequency-aware negative prompts to suppress hallucinations and semantic drift. Extensive experiments on synthetic and real-world benchmarks show that DTPSR achieves high perceptual quality, competitive fidelity, and strong generalization across diverse degradation scenarios.
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Submitted 7 March, 2026;
originally announced March 2026.
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Latent Autoencoder Ensemble Kalman Filter for Data assimilation
Authors:
Xin T. Tong,
Yanyan Wang,
Liang Yan
Abstract:
The ensemble Kalman filter (EnKF) is widely used for data assimilation in high-dimensional systems, but its performance often deteriorates for strongly nonlinear dynamics due to the structural mismatch between the Kalman update and the underlying system behavior. In this work, we propose a latent autoencoder ensemble Kalman filter (LAE-EnKF) that addresses this limitation by reformulating the assi…
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The ensemble Kalman filter (EnKF) is widely used for data assimilation in high-dimensional systems, but its performance often deteriorates for strongly nonlinear dynamics due to the structural mismatch between the Kalman update and the underlying system behavior. In this work, we propose a latent autoencoder ensemble Kalman filter (LAE-EnKF) that addresses this limitation by reformulating the assimilation problem in a learned latent space with linear and stable dynamics. The proposed method learns a nonlinear encoder--decoder together with a stable linear latent evolution operator and a consistent latent observation mapping, yielding a closed linear state-space model in the latent coordinates. This construction restores compatibility with the Kalman filtering framework and allows both forecast and analysis steps to be carried out entirely in the latent space. Compared with existing autoencoder-based and latent assimilation approaches that rely on unconstrained nonlinear latent dynamics, the proposed formulation emphasizes structural consistency, stability, and interpretability. We provide a theoretical analysis of learning linear dynamics on low-dimensional manifolds and establish generalization error bounds for the proposed latent model. Numerical experiments on representative nonlinear and chaotic systems demonstrate that the LAE-EnKF yields more accurate and stable assimilation than the standard EnKF and related latent-space methods, while maintaining comparable computational cost and data-driven.
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Submitted 6 March, 2026;
originally announced March 2026.
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Hierarchical Industrial Demand Forecasting with Temporal and Uncertainty Explanations
Authors:
Harshavardhan Kamarthi,
Shangqing Xu,
Xinjie Tong,
Xingyu Zhou,
James Peters,
Joseph Czyzyk,
B. Aditya Prakash
Abstract:
Hierarchical time-series forecasting is essential for demand prediction across various industries. While machine learning models have obtained significant accuracy and scalability on such forecasting tasks, the interpretability of their predictions, informed by application, is still largely unexplored. To bridge this gap, we introduce a novel interpretability method for large hierarchical probabil…
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Hierarchical time-series forecasting is essential for demand prediction across various industries. While machine learning models have obtained significant accuracy and scalability on such forecasting tasks, the interpretability of their predictions, informed by application, is still largely unexplored. To bridge this gap, we introduce a novel interpretability method for large hierarchical probabilistic time-series forecasting, adapting generic interpretability techniques while addressing challenges associated with hierarchical structures and uncertainty. Our approach offers valuable interpretative insights in response to real-world industrial supply chain scenarios, including 1) the significance of various time-series within the hierarchy and external variables at specific time points, 2) the impact of different variables on forecast uncertainty, and 3) explanations for forecast changes in response to modifications in the training dataset. To evaluate the explainability method, we generate semi-synthetic datasets based on real-world scenarios of explaining hierarchical demands for over ten thousand products at a large chemical company. The experiments showed that our explainability method successfully explained state-of-the-art industrial forecasting methods with significantly higher explainability accuracy. Furthermore, we provide multiple real-world case studies that show the efficacy of our approach in identifying important patterns and explanations that help stakeholders better understand the forecasts. Additionally, our method facilitates the identification of key drivers behind forecasted demand, enabling more informed decision-making and strategic planning. Our approach helps build trust and confidence among users, ultimately leading to better adoption and utilization of hierarchical forecasting models in practice.
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Submitted 6 March, 2026;
originally announced March 2026.
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Expert Divergence Learning for MoE-based Language Models
Authors:
Jiaang Li,
Haibin Chen,
Langming Liu,
Yujin Yuan,
Yadao Wang,
Yizhen Zhang,
Chengting Yu,
Xin Tong,
Weidong Zhang,
Shilei Liu,
Wenbo Su,
Bo Zheng
Abstract:
The Mixture-of-Experts (MoE) architecture is a powerful technique for scaling language models, yet it often suffers from expert homogenization, where experts learn redundant functionalities, thereby limiting MoE's full potential. To address this, we introduce Expert Divergence Learning, a novel pre-training strategy that explicitly encourages functional specialization among experts. Our method inc…
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The Mixture-of-Experts (MoE) architecture is a powerful technique for scaling language models, yet it often suffers from expert homogenization, where experts learn redundant functionalities, thereby limiting MoE's full potential. To address this, we introduce Expert Divergence Learning, a novel pre-training strategy that explicitly encourages functional specialization among experts. Our method incorporates a label-driven auxiliary loss that leverages domain labels inherent in pre-training corpora to maximize the Jensen-Shannon Divergence between the expert routing distributions of different data domains. This optimization objective guides the model to develop diverged routing policies for varied domains and closer routing policies for the same domain, which leads to emergent and organized expert specialization. We validate our approach by pre-training MoE models of up to 15 billion parameters from scratch. Experimental results demonstrate that models trained with Expert Divergence Learning not only achieve a lower language modeling loss but also exhibit significant performance improvements across a diverse range of downstream benchmarks. Further analysis confirms that our method effectively mitigates expert homogenization and brings greater functional specialization, all with negligible computational overhead during training.
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Submitted 10 February, 2026;
originally announced March 2026.
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Development and Application of an eV Neutron Polarization for Parity Violation Studies at CSNS Back-n Beamline
Authors:
Xu Qin,
Tianhao Wang,
Xuanbo Chen,
Changdong Deng,
Yongce Gong,
Zenghang Huang,
Wei Jiang,
Zhengquan Liu,
Guangyuan Luan,
Haotian Luo,
Qiuyue Luo,
Yongjia Lv,
You Lv,
Nikolaos Vassilopoulos,
Xichao Ruan,
William Michael Snow,
Kang Sun,
Sepehr Samiei,
Jian Tang,
Shilin Wang,
Hongyi Wu,
Xiaomin Xiong,
Xinyu Yuan,
Junpei Zhang,
Mofan Zhang
, et al. (4 additional authors not shown)
Abstract:
The dynamic enhancement of symmetry-breaking effects in neutron-nucleus resonances provides a sensitive testing ground for Time-Reversal Invariance Violation (TRIV). Exploiting this mechanism, the Neutron Optics Parity and Time Reversal Experiment (NOPTREX) seeks to elucidate the origin of the universe's baryon asymmetry. Critical to this effort is the precise measurement of Parity Violation (PV)…
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The dynamic enhancement of symmetry-breaking effects in neutron-nucleus resonances provides a sensitive testing ground for Time-Reversal Invariance Violation (TRIV). Exploiting this mechanism, the Neutron Optics Parity and Time Reversal Experiment (NOPTREX) seeks to elucidate the origin of the universe's baryon asymmetry. Critical to this effort is the precise measurement of Parity Violation (PV) asymmetries, which is essential to calibrate the nuclear parameters required for future TRIV experiments. To facilitate these studies, we developed an eV polarized neutron at the Back-n white neutron beamline of the China Spallation Neutron Source (CSNS). Neutron polarization is generated by an in-situ Spin-Exchange Optical Pumping (SEOP) $^3$He filter. Spin manipulation is performed by an adiabatic spin flipper, while spin polarization is preserved over the flight path by a vacuum transport system equipped with a solenoidal guide field. Experiments successfully measured an asymmetry of approximately $7.8 \pm 2.4$ (stat.) $\pm 0.3$ (sys.) % at the 0.747 eV p-wave resonance of $^{139}$La. These results are in agreement with previous results on this resonance and validate the system's capability for PV measurements.
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Submitted 19 February, 2026;
originally announced February 2026.
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Tree crop mapping of South America reveals links to deforestation and conservation
Authors:
Yuchang Jiang,
Anton Raichuk,
Xiaoye Tong,
Vivien Sainte Fare Garnot,
Daniel Ortiz-Gonzalo,
Dan Morris,
Konrad Schindler,
Jan Dirk Wegner,
Maxim Neumann
Abstract:
Monitoring tree crop expansion is vital for zero-deforestation policies like the European Union's Regulation on Deforestation-free Products (EUDR). However, these efforts are hindered by a lack of highresolution data distinguishing diverse agricultural systems from forests. Here, we present the first 10m-resolution tree crop map for South America, generated using a multi-modal, spatio-temporal dee…
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Monitoring tree crop expansion is vital for zero-deforestation policies like the European Union's Regulation on Deforestation-free Products (EUDR). However, these efforts are hindered by a lack of highresolution data distinguishing diverse agricultural systems from forests. Here, we present the first 10m-resolution tree crop map for South America, generated using a multi-modal, spatio-temporal deep learning model trained on Sentinel-1 and Sentinel-2 satellite imagery time series. The map identifies approximately 11 million hectares of tree crops, 23% of which is linked to 2000-2020 forest cover loss. Critically, our analysis reveals that existing regulatory maps supporting the EUDR often classify established agriculture, particularly smallholder agroforestry, as "forest". This discrepancy risks false deforestation alerts and unfair penalties for small-scale farmers. Our work mitigates this risk by providing a high-resolution baseline, supporting conservation policies that are effective, inclusive, and equitable.
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Submitted 24 February, 2026; v1 submitted 19 February, 2026;
originally announced February 2026.
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Polarization measurement of $Λ^+_c$ and $\overlineΛ{}^-_c$ baryons in $p$Ne collisions at $\sqrt{s_{NN}} = 68.6$ GeV
Authors:
LHCb collaboration,
R. Aaij,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis,
L. An
, et al. (1171 additional authors not shown)
Abstract:
The first measurement of the polarization of charm baryons by the LHCb experiment recorded in fixed-target mode is presented. The polarization of $Λ_c$ baryons is studied in collisions of protons, at an energy of 2.51 TeV, incident on a gaseous target of neon, at a nucleon-nucleon center-of-mass energy of $68.6$ GeV. The world's first measurement of separate-charge polarizations for $Λ^+_c$ and…
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The first measurement of the polarization of charm baryons by the LHCb experiment recorded in fixed-target mode is presented. The polarization of $Λ_c$ baryons is studied in collisions of protons, at an energy of 2.51 TeV, incident on a gaseous target of neon, at a nucleon-nucleon center-of-mass energy of $68.6$ GeV. The world's first measurement of separate-charge polarizations for $Λ^+_c$ and $\overlineΛ{}^-_c$ baryons is performed, determining $$ P_{Λ^+_c} = ( 24 \pm 9 \pm 2 \, )\% , $$ $$ P_{\overlineΛ{}^-_c} = (-8 \pm 12 \pm 3 \, ) \% , $$ where the first uncertainty is statistical and the second systematic. The polarization is also measured in intervals of baryon transverse momentum and the Feynman-$x$ variable.
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Submitted 19 February, 2026;
originally announced February 2026.
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How Do We Research Human-Robot Interaction in the Age of Large Language Models? A Systematic Review
Authors:
Yufeng Wang,
Yuan Xu,
Anastasia Nikolova,
Yuxuan Wang,
Jianyu Wang,
Chongyang Wang,
Xin Tong
Abstract:
Advances in large language models (LLMs) are profoundly reshaping the field of human-robot interaction (HRI). While prior work has highlighted the technical potential of LLMs, few studies have systematically examined their human-centered impact (e.g., human-oriented understanding, user modeling, and levels of autonomy), making it difficult to consolidate emerging challenges in LLM-driven HRI syste…
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Advances in large language models (LLMs) are profoundly reshaping the field of human-robot interaction (HRI). While prior work has highlighted the technical potential of LLMs, few studies have systematically examined their human-centered impact (e.g., human-oriented understanding, user modeling, and levels of autonomy), making it difficult to consolidate emerging challenges in LLM-driven HRI systems. Therefore, we conducted a systematic literature search following the PRISMA guideline, identifying 86 articles that met our inclusion criteria. Our findings reveal that: (1) LLMs are transforming the fundamentals of HRI by reshaping how robots sense context, generate socially grounded interactions, and maintain continuous alignment with human needs in embodied settings; and (2) current research is largely exploratory, with different studies focusing on different facets of LLM-driven HRI, resulting in wide-ranging choices of experimental setups, study methods, and evaluation metrics. Finally, we identify key design considerations and challenges, offering a coherent overview and guidelines for future research at the intersection of LLMs and HRI.
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Submitted 13 February, 2026;
originally announced February 2026.
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A method for luminosity determination based on real-time hit reconstruction with the LHCb silicon pixel detector
Authors:
LHCb collaboration,
R. Aaij,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis,
L. An
, et al. (1175 additional authors not shown)
Abstract:
The data acquisition system of the upgraded LHCb experiment includes the fast reconstruction of all hits in the vertex locator (VELO) pixel detector at the beam-crossing rate of 40 MHz, implemented as on-the-fly clustering embedded in the firmware of the readout board FPGAs. The availability of a high rate of reconstructed clusters in real time enables a new fast approach for measuring luminosity…
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The data acquisition system of the upgraded LHCb experiment includes the fast reconstruction of all hits in the vertex locator (VELO) pixel detector at the beam-crossing rate of 40 MHz, implemented as on-the-fly clustering embedded in the firmware of the readout board FPGAs. The availability of a high rate of reconstructed clusters in real time enables a new fast approach for measuring luminosity and monitoring the LHCb luminous region, directly at the detector readout level. This methodology has been implemented as an array of real-time cluster counters in the VELO readout FPGAs and has been in operation since the start of the 2024 physics run of LHCb. This paper describes the methodology and its features and performance, both on proton-proton and lead-lead collision data. The method shows a statistical resolution better than the percent level, and a sensitivity to variable running conditions of the same level. This is achieved with an intrinsic time granularity better than 100 ms , undersampled to 3 s for analysis purposes. Nonlinear behaviour is compatible with zero in a luminosity range including the LHCb Run 3 operating point.
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Submitted 15 February, 2026;
originally announced February 2026.
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Denoise Stepwise Signals by Diffusion Model Based Approach
Authors:
Xingdi Tong,
Chenyu Wen
Abstract:
Stepwise signals are ubiquitous in single-molecule detections, where abrupt changes in signal levels typically correspond to molecular conformational changes or state transitions. However, these features are inevitably obscured by noise, leading to uncertainty in estimating both signal levels and transition points. Traditional frequency-domain filtering is ineffective for denoising stepwise signal…
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Stepwise signals are ubiquitous in single-molecule detections, where abrupt changes in signal levels typically correspond to molecular conformational changes or state transitions. However, these features are inevitably obscured by noise, leading to uncertainty in estimating both signal levels and transition points. Traditional frequency-domain filtering is ineffective for denoising stepwise signals, as edge-related high-frequency components strongly overlap with noise. Although Hidden Markov Model-based approaches are widely used, they rely on stationarity assumptions and are not specifically designed for signal denoising. Here, we propose a diffusion model-based algorithm for stepwise signal denoising, named the Stepwise Signal Diffusion Model (SSDM). During training, SSDM learns the statistical structure of stepwise signals via a forward diffusion process that progressively adds noise. In the following reverse process, the model reconstructs clean signals from noisy observations, integrating a multi-scale convolutional network with an attention mechanism. Training data are generated by simulating stepwise signals through a Markov process with additive Gaussian noise. Across a broad range of signal-to-noise ratios, SSDM consistently outperforms traditional methods in both signal level reconstruction and transition point detection. Its effectiveness is further demonstrated on experimental data from single-molecule Forster Resonance Energy Transfer and nanopore DNA translocation measurements. Overall, SSDM provides a general and robust framework for recovering stepwise signals in various single-molecule detections and other physical systems exhibiting discrete state transitions.
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Submitted 9 February, 2026;
originally announced February 2026.
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Physics-Inspired Target Shape Detection and Reconstruction in mmWave Communication Systems
Authors:
Ziqing Xing,
Zhaoyang Zhang,
Xin Tong,
Zhaohui Yang,
Chongwen Huang
Abstract:
The integration of sensing and communication (ISAC) is an essential function of future wireless systems. Due to its large available bandwidth, millimeter-wave (mmWave) ISAC systems are able to achieve high sensing accuracy. In this paper, we consider the multiple base-station (BS) collaborative sensing problem in a multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) m…
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The integration of sensing and communication (ISAC) is an essential function of future wireless systems. Due to its large available bandwidth, millimeter-wave (mmWave) ISAC systems are able to achieve high sensing accuracy. In this paper, we consider the multiple base-station (BS) collaborative sensing problem in a multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) mmWave communication system. Our aim is to sense a remote target shape with the collected signals which consist of both the reflection and scattering signals. We first characterize the mmWave's scattering and reflection effects based on the Lambertian scattering model. Then we apply the periodogram technique to obtain rough scattering point detection, and further incorporate the subspace method to achieve more precise scattering and reflection point detection. Based on these, a reconstruction algorithm based on Hough Transform and principal component analysis (PCA) is designed for a single convex polygon target scenario. To improve the accuracy and completeness of the reconstruction results, we propose a method to further fuse the scattering and reflection points. Extensive simulation results validate the effectiveness of the proposed algorithms.
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Submitted 5 February, 2026;
originally announced February 2026.
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PretrainRL: Alleviating Factuality Hallucination of Large Language Models at the Beginning
Authors:
Langming Liu,
Kangtao Lv,
Haibin Chen,
Weidong Zhang,
Yejing Wang,
Shilei Liu,
Xin Tong,
Yujin Yuan,
Yongwei Wang,
Wenbo Su,
Bo Zheng
Abstract:
Large language models (LLMs), despite their powerful capabilities, suffer from factual hallucinations where they generate verifiable falsehoods. We identify a root of this issue: the imbalanced data distribution in the pretraining corpus, which leads to a state of "low-probability truth" and "high-probability falsehood". Recent approaches, such as teaching models to say "I don't know" or post-hoc…
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Large language models (LLMs), despite their powerful capabilities, suffer from factual hallucinations where they generate verifiable falsehoods. We identify a root of this issue: the imbalanced data distribution in the pretraining corpus, which leads to a state of "low-probability truth" and "high-probability falsehood". Recent approaches, such as teaching models to say "I don't know" or post-hoc knowledge editing, either evade the problem or face catastrophic forgetting. To address this issue from its root, we propose \textbf{PretrainRL}, a novel framework that integrates reinforcement learning into the pretraining phase to consolidate factual knowledge. The core principle of PretrainRL is "\textbf{debiasing then learning}." It actively reshapes the model's probability distribution by down-weighting high-probability falsehoods, thereby making "room" for low-probability truths to be learned effectively. To enable this, we design an efficient negative sampling strategy to discover these high-probability falsehoods and introduce novel metrics to evaluate the model's probabilistic state concerning factual knowledge. Extensive experiments on three public benchmarks demonstrate that PretrainRL significantly alleviates factual hallucinations and outperforms state-of-the-art methods.
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Submitted 2 February, 2026;
originally announced February 2026.
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Quasiperiodic Skin Criticality in an Exactly Solvable Non-Hermitian Quasicrystal
Authors:
Zhangyuan Chen,
Muhammad Idrees,
Ying Yang,
Xianqi Tong,
Xiaosen Yang
Abstract:
Critical states in quasiperiodic systems defy the conventional dichotomy between extended and localized states. In this work, we demonstrate that non-Hermiticity fundamentally reshapes this paradigm by giving rise to an exactly solvable quasiperiodic critical phase with no energy selectivity. We introduce a non-Hermitian quasiperiodic lattice based on a modulated Hatano-Nelson model and uncover a…
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Critical states in quasiperiodic systems defy the conventional dichotomy between extended and localized states. In this work, we demonstrate that non-Hermiticity fundamentally reshapes this paradigm by giving rise to an exactly solvable quasiperiodic critical phase with no energy selectivity. We introduce a non-Hermitian quasiperiodic lattice based on a modulated Hatano-Nelson model and uncover a new universality class of quasiperiodic skin criticality, in which all eigenstates share an identical multifractal spatial structure. Through a nonunitary gauge transformation, the system is mapped onto a disorder-free lattice, enabling exact analytical solutions for the full spectrum and eigenstates. As a consequence, the inverse participation ratio is strictly energy-independent and controlled solely by a global phase. We further show that this criticality persists in multiband lattices, establishing a general and analytically controlled framework for non-Hermitian quasiperiodic critical phenomena.
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Submitted 30 January, 2026;
originally announced January 2026.
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Spectral Gap of Metropolis Algorithms for Non-smooth Distributions under Isoperimetry
Authors:
Shuigen Liu,
Xin T. Tong
Abstract:
Metropolis algorithms are classical tools for sampling from target distributions, with broad applications in statistics and scientific computing. Their convergence speed is governed by the spectral gap of the associated Markov operator. Recently, Andrieu et al. (2024) derived the first explicit bounds for the spectral gap of Random--Walk Metropolis when the target distribution is smooth and strong…
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Metropolis algorithms are classical tools for sampling from target distributions, with broad applications in statistics and scientific computing. Their convergence speed is governed by the spectral gap of the associated Markov operator. Recently, Andrieu et al. (2024) derived the first explicit bounds for the spectral gap of Random--Walk Metropolis when the target distribution is smooth and strongly log-concave. However, existing literature rarely discusses non-smooth targets. In this work, we derive explicit spectral gap bounds for the random-walk Metropolis and Metropolis--adjusted Langevin algorithms over a broad class of non-smooth distributions. Moreover, combining our analysis with a recent result in Goyal et al. (2025), we extend these bounds to targets satisfying a Poincare or log-Sobolev inequality, beyond the strongly log-concave setting. Our theoretical results are further supported by numerical experiments.
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Submitted 10 April, 2026; v1 submitted 29 January, 2026;
originally announced January 2026.
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Why Attention Patterns Exist: A Unifying Temporal Perspective Analysis
Authors:
Qingyue Yang,
Jie Wang,
Xing Li,
Yinqi Bai,
Xialiang Tong,
Huiling Zhen,
Jianye Hao,
Mingxuan Yuan,
Bin Li
Abstract:
Attention patterns play a crucial role in both training and inference of large language models (LLMs). Prior works have identified individual patterns such as retrieval heads, sink heads, and diagonal traces, yet these observations remain fragmented and lack a unifying explanation. To bridge this gap, we introduce \textbf{Temporal Attention Pattern Predictability Analysis (TAPPA), a unifying frame…
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Attention patterns play a crucial role in both training and inference of large language models (LLMs). Prior works have identified individual patterns such as retrieval heads, sink heads, and diagonal traces, yet these observations remain fragmented and lack a unifying explanation. To bridge this gap, we introduce \textbf{Temporal Attention Pattern Predictability Analysis (TAPPA), a unifying framework that explains diverse attention patterns by analyzing their underlying mathematical formulations} from a temporally continuous perspective. TAPPA both deepens the understanding of attention behavior and guides inference acceleration approaches. Specifically, TAPPA characterizes attention patterns as predictable patterns with clear regularities and unpredictable patterns that appear effectively random. Our analysis further reveals that this distinction can be explained by the degree of query self-similarity along the temporal dimension. Focusing on the predictable patterns, we further provide a detailed mathematical analysis of three representative cases through the joint effect of queries, keys, and Rotary Positional Embeddings (RoPE). We validate TAPPA by applying its insights to KV cache compression and LLM pruning tasks. Across these tasks, a simple metric motivated by TAPPA consistently improves performance over baseline methods. The code is available at https://github.com/MIRALab-USTC/LLM-TAPPA.
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Submitted 29 January, 2026;
originally announced January 2026.
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Observation of the decay $χ_{c1}(3872)\rightarrow J\mskip -3mu/\mskip -2muψμ^+μ^-$
Authors:
LHCb collaboration,
R. Aaij,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
M. Akthar,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis
, et al. (1181 additional authors not shown)
Abstract:
The first observation of the $χ_{c1}(3872)\rightarrow J\mskip -3mu/\mskip -2muψμ^+μ^-$ decay is reported using proton-proton collision data recorded with the LHCb detector corresponding to an integrated luminosity of $9fb^{-1}$. The decay mode is observed for the first time, with a significance of $6.5σ$. Its branching fraction is measured relative to the…
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The first observation of the $χ_{c1}(3872)\rightarrow J\mskip -3mu/\mskip -2muψμ^+μ^-$ decay is reported using proton-proton collision data recorded with the LHCb detector corresponding to an integrated luminosity of $9fb^{-1}$. The decay mode is observed for the first time, with a significance of $6.5σ$. Its branching fraction is measured relative to the $χ_{c1}(3872)\rightarrow J\mskip -3mu/\mskip -2muψπ^+π^-$ decay mode \begin{align*} \frac{\cal{BF}(χ_{c1}(3872)\rightarrow J\mskip -3mu/\mskip -2muψμ^+μ^-)}{\cal{BF}(χ_{c1}(3872)\rightarrow J\mskip -3mu/\mskip -2muψπ^+π^-)} = \left(1.64\pm 0.32\pm 0.05\right)\times10^{-3}, \end{align*} where the first uncertainty includes both statistical contributions and systematic contributions which are uncorrelated between data-taking periods, and the second represents the systematic contributions that are correlated between data-taking periods.
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Submitted 28 January, 2026;
originally announced January 2026.
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Search for $τ^-\to μ^-μ^+μ^-$ decays at the LHCb experiment with Run 2 data
Authors:
LHCb collaboration,
R. Aaij,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
M. Akthar,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis
, et al. (1185 additional authors not shown)
Abstract:
A search for the lepton-flavour-violating decay $τ^-\to μ^-μ^+μ^-$ is carried out using data collected by the LHCb experiment between 2016 and 2018 in proton-proton collisions at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb$^{-1}$. An upper limit of $1.9\,(2.3)\times 10^{-8}$ is set at the 90% (95%) confidence level on the branching fraction of…
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A search for the lepton-flavour-violating decay $τ^-\to μ^-μ^+μ^-$ is carried out using data collected by the LHCb experiment between 2016 and 2018 in proton-proton collisions at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb$^{-1}$. An upper limit of $1.9\,(2.3)\times 10^{-8}$ is set at the 90% (95%) confidence level on the branching fraction of the decay.
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Submitted 28 January, 2026;
originally announced January 2026.
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Energy shift of Fe-K fluorescence lines due to low ionization demonstrated with XRISM in Centaurus X-3
Authors:
Yutaro Nagai,
Teruaki Enoto,
Masahiro Tsujimoto,
Hiroya Yamaguchi,
Yuto Mochizuki,
Ehud Behar,
Lia Corrales,
Paul A. Draghis,
Ken Ebisawa,
Natalie Hell,
Timothy R. Kallman,
Richard L. Kelley,
Pragati Pradhan,
Shinya Yamada,
Toshiyuki Azuma,
Xiao-Min Tong
Abstract:
The Fe K$α$ fluorescence line at 6.4 keV is a powerful probe of cold matter surrounding X-ray sources and has been widely used in various astrophysical contexts. The X-ray microcalorimeter spectrometer onboard XRISM can measure line shifts with unprecedented precision of $\sim$0.2 eV, equivalent to a line-of-sight velocity of $\sim$10 km s$^{-1}$. At this level of accuracy, however, several factor…
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The Fe K$α$ fluorescence line at 6.4 keV is a powerful probe of cold matter surrounding X-ray sources and has been widely used in various astrophysical contexts. The X-ray microcalorimeter spectrometer onboard XRISM can measure line shifts with unprecedented precision of $\sim$0.2 eV, equivalent to a line-of-sight velocity of $\sim$10 km s$^{-1}$. At this level of accuracy, however, several factors that influence the line energy must be carefully considered prior to astrophysical interpretation. One such important factor is the ionization degree, Fe$^{q+}$. The K$α$ line shifts redward by $\sim$4 eV as $q$ increases from 0 (neutral) to 8 (Ar-like). Additionally, the accompanying Fe K$β$ line at 7.06 keV shifts blueward by $\sim$30 eV from $q=0$ to 8. We demonstrate that this effect is actually observable in the XRISM data of the high-mass X-ray binary Centaurus X-3 (Cen X-3). We advocate that the differential energy shift between the K$α$ and K$β$ line provides a robust estimate of $q$ by decoupling from other effects that shift the two lines in the same direction. We derived $q \sim 5$ (Sc-like) for the fluorescing matter by comparing the observation with atomic structure calculations of our own and in the literature. By accounting for the derived charge state and the corresponding shift in the rest-frame line energy, we made corrections for this effect and reached a consistent residual shift among the K$α$, K$β$, and the optical measurement attributable to the systemic velocity of the system. Consequently, we obtained a new constraint on the location of the cold matter. This ionization effect needs to be assessed in all use cases of the Fe K$α$ line shift beyond Cen X-3, and the proposed metric is generally applicable to all of them.
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Submitted 25 January, 2026;
originally announced January 2026.
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Reflexa: Uncovering How LLM-Supported Reflection Scaffolding Reshapes Creativity in Creative Coding
Authors:
Anqi Wang,
Zhengyi Li,
Lan Luo,
Xin Tong,
Pan Hui
Abstract:
Creative coding requires continuous translation between evolving concepts and computational artifacts, making reflection essential yet difficult to sustain. Creators often struggle to manage ambiguous intentions, emergent outputs, and complex code, limiting depth of exploration. This work examines how large language models (LLMs) can scaffold reflection not as isolated prompts, but as a system-lev…
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Creative coding requires continuous translation between evolving concepts and computational artifacts, making reflection essential yet difficult to sustain. Creators often struggle to manage ambiguous intentions, emergent outputs, and complex code, limiting depth of exploration. This work examines how large language models (LLMs) can scaffold reflection not as isolated prompts, but as a system-level mechanism shaping creative regulation. From formative studies with eight expert creators, we derived reflection challenges and design principles that informed Reflexa, an integrated scaffold combining dialogic guidance, visualized version navigation, and iterative suggestion pathways. A within-subject study with 18 participants provides an exploratory mechanism validation, showing that structured reflection patterns mediate the link between AI interaction and creative outcomes. These reflection trajectories enhanced perceived controllability, broadened exploration, and improved originality and aesthetic quality. Our findings advance HCI understanding of reflection from LLM-assisted creative practices, and provide design strategies for building LLM-based creative tools that support richer human-AI co-creativity.
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Submitted 25 January, 2026;
originally announced January 2026.
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Co-Designing Digital Humans for Online Learning: A Framework for Human-AI Pedagogical Integration
Authors:
Xiaokang Lei,
Ching Christie Pang,
Yuyang Jiang,
Xin Tong,
Pan Hui
Abstract:
Artificial intelligence (AI) and large language models (LLMs) are reshaping education, with virtual avatars emerging as digital teachers capable of enhancing engagement, sustaining attention, and addressing instructor shortages. Aligned with the Sustainable Development Goals (SDGs) for equitable quality education, these technologies hold promise yet lack clear guidelines for effective design and i…
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Artificial intelligence (AI) and large language models (LLMs) are reshaping education, with virtual avatars emerging as digital teachers capable of enhancing engagement, sustaining attention, and addressing instructor shortages. Aligned with the Sustainable Development Goals (SDGs) for equitable quality education, these technologies hold promise yet lack clear guidelines for effective design and implementation in online learning. To fill this gap, we introduce a framework specifying when, what, and how digital teachers should be integrated. Our study combines (1) a design space analysis of 87 works across AI, educational technology, design, and HCI, (2) a survey of 132 learners' practices and preferences, and (3) three co-design workshops with 18 experts from pedagogy, design, and AI. It provides actionable guidance for educators, designers, and HCI researchers, advancing opportunities to build more engaging, equitable, and effective online learning environments powered by digital teachers.
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Submitted 24 January, 2026;
originally announced January 2026.
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Machine learning techniques for jet reconstruction at LHCb and application to the search for $H \to b \bar{b}$ and $H \to c \bar{c}$ in $\sqrt{s}=13$ TeV $pp$ collisions
Authors:
LHCb collaboration,
R. Aaij,
A. S. W. Abdelmotteleb,
C. Abellan Beteta,
F. Abudinén,
T. Ackernley,
A. A. Adefisoye,
B. Adeva,
M. Adinolfi,
P. Adlarson,
C. Agapopoulou,
C. A. Aidala,
Z. Ajaltouni,
S. Akar,
K. Akiba,
M. Akthar,
P. Albicocco,
J. Albrecht,
R. Aleksiejunas,
F. Alessio,
P. Alvarez Cartelle,
R. Amalric,
S. Amato,
J. L. Amey,
Y. Amhis
, et al. (1191 additional authors not shown)
Abstract:
Two machine learning techniques for jet measurements at the LHCb experiment are presented: a regression-based method for jet-energy calibration and a deep neural network algorithm for jet flavour tagging, distinguishing between $b$-quark, $c$-quark, and light parton jets. These techniques are applied to a search for inclusive $H \to \bbbar$ and $H \to c\barcc$ decays using a LHCb dataset correspon…
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Two machine learning techniques for jet measurements at the LHCb experiment are presented: a regression-based method for jet-energy calibration and a deep neural network algorithm for jet flavour tagging, distinguishing between $b$-quark, $c$-quark, and light parton jets. These techniques are applied to a search for inclusive $H \to \bbbar$ and $H \to c\barcc$ decays using a LHCb dataset corresponding to an integrated luminosity of 1.6\invfb. The observed (expected) 95\% confidence level upper limits correspond to 6.6 (11.1) times the SM cross-section for the $H \to b\bar b$ process, and 1003 (1834) times the SM cross-section for the $H \to c\bar c$ process.
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Submitted 23 January, 2026;
originally announced January 2026.
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Learning to Optimize by Differentiable Programming
Authors:
Liping Tao,
Xindi Tong,
Chee Wei Tan
Abstract:
Solving massive-scale optimization problems requires scalable first-order methods with low per-iteration cost. This tutorial highlights a shift in optimization: using differentiable programming not only to execute algorithms but to learn how to design them. Modern frameworks such as PyTorch, TensorFlow, and JAX enable this paradigm through efficient automatic differentiation. Embedding first-order…
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Solving massive-scale optimization problems requires scalable first-order methods with low per-iteration cost. This tutorial highlights a shift in optimization: using differentiable programming not only to execute algorithms but to learn how to design them. Modern frameworks such as PyTorch, TensorFlow, and JAX enable this paradigm through efficient automatic differentiation. Embedding first-order methods within these systems allows end-to-end training that improves convergence and solution quality. Guided by Fenchel-Rockafellar duality, the tutorial demonstrates how duality-informed iterative schemes such as ADMM and PDHG can be learned and adapted. Case studies across LP, OPF, Laplacian regularization, and neural network verification illustrate these gains.
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Submitted 27 February, 2026; v1 submitted 23 January, 2026;
originally announced January 2026.