Showing 1–50 of 235 results for author: Park, S

Post-Inflationary Constraints on Nonminimally Coupled Quintessential Inflation

Authors: Min Gi Park, Seong Chan Park, Tomo Takahashi, José Jaime Terente Díaz

Abstract: We investigate quintessential inflation in a nonminimally coupled scalar-tensor theory, parameterizing the post-inflationary radiation abundance independently of the reheating mechanism. The nonadiabatic inflation-kination transition generates a stochastic gravitational-wave background whose contribution to $ΔN_{\textrm{eff}}$ imposes a lower limit on the reheating temperature. Because this temper… ▽ More We investigate quintessential inflation in a nonminimally coupled scalar-tensor theory, parameterizing the post-inflationary radiation abundance independently of the reheating mechanism. The nonadiabatic inflation-kination transition generates a stochastic gravitational-wave background whose contribution to $ΔN_{\textrm{eff}}$ imposes a lower limit on the reheating temperature. Because this temperature dictates the duration of kination and the available scalar-field excursion, it directly constrains the present-day dark-energy equation of state. While a single-exponential coupling achieves the required post-inflationary potential drop, the same constant slope does not provide viable late-time acceleration. A double-exponential deformation resolves this tension by decoupling the average slope governing the total potential drop from the asymptotic slope driving cosmic acceleration. Full numerical solutions confirm this picture, yielding a thawing quintessence regime with $w_{\varphi,0}\simeq (-0.90, -0.95)$ for our benchmarks. Our results demonstrate that future dark-energy measurements can directly probe the post-inflationary reheating history of the Universe. △ Less

Submitted 5 August, 2026; originally announced August 2026.

Comments: 54 pages, 9 figures, 1 table, 1 appendix

High-Frequency Gravitational Wave Detection with Superconducting Qubits

Authors: Heechan Yi, Seong Chan Park, Kyoungchul Kong, Myeonghun Park

Abstract: High-frequency gravitational waves (HFGWs) provide a unique window into high-energy and early-universe physics, yet they evade traditional macroscopic interferometry. To bridge this detection gap, we propose a novel quantum-sensing paradigm utilizing superconducting transmon qubits embedded in resonant microwave cavities. Through the inverse Gertsenshtein effect, HFGWs propagating in a static magn… ▽ More High-frequency gravitational waves (HFGWs) provide a unique window into high-energy and early-universe physics, yet they evade traditional macroscopic interferometry. To bridge this detection gap, we propose a novel quantum-sensing paradigm utilizing superconducting transmon qubits embedded in resonant microwave cavities. Through the inverse Gertsenshtein effect, HFGWs propagating in a static magnetic field resonantly excite a cavity mode. By leveraging the characteristic spin-2 quadrupolar pattern of the induced electromagnetic field, we position qubits directly at the electric-field hot spots of the $\mathrm{TE}_{212}$ mode to act as localized sensors. Crucially, configuring this array as an entangled quantum register via symmetric Dicke states unlocks a fundamental scaling advantage: the signal probability scales quadratically with the qubit number, translating to a $h_{\min} \propto n_q^{-3/4}$ strain sensitivity scaling. We demonstrate that an idealized global register of 800 qubits reaches a strain sensitivity that surpasses standard macroscopic cavity-power limits by five orders of magnitude. Benchmarked against representative axion-haloscope parameters, this collective quantum enhancement decisively mitigates the profound Planck-scale suppression inherent to gravitational interactions, establishing a transformative framework for next-generation HFGW searches in the GHz band. △ Less

Submitted 3 August, 2026; originally announced August 2026.

First measurement of the masses of the $Υ_1(1D)$ and $Υ_3(1D)$ states and the energy dependence of the cross sections for $e^+e^-\toΥ_J(1D)η$ and $e^+e^-\toΥ_J(1D)π^+π^-$

Authors: Belle, Belle II Collaborations, :, M. Abumusabh, I. Adachi, K. Adamczyk, A. Aggarwal, H. Ahmed, Y. Ahn, M. Akdag, N. Akopov, S. Alghamdi, M. Alhakami, N. Althubiti, K. Amos, M. Angelsmark, N. Anh Ky, C. Antonioli, K. Arai, H. Atmacan, T. Aushev, V. Aushev, R. Ayad, V. Babu, H. Bae , et al. (376 additional authors not shown)

Abstract: We study the processes $e^+e^-\toΥ_J(1D)η$ and $e^+e^-\toΥ_J(1D)π^+π^-$ at center-of-mass energies $\sqrt{s}$=(10.73 -- 11.02) GeV using a $142.5\,\mathrm{fb}^{-1}$ data sample, including 122~fb$^{-1}$ near the $Υ$(10860) peak ($\sqrt{s}$ = 10.866 GeV), collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. From the peak sample, the products of Born cross section times… ▽ More We study the processes $e^+e^-\toΥ_J(1D)η$ and $e^+e^-\toΥ_J(1D)π^+π^-$ at center-of-mass energies $\sqrt{s}$=(10.73 -- 11.02) GeV using a $142.5\,\mathrm{fb}^{-1}$ data sample, including 122~fb$^{-1}$ near the $Υ$(10860) peak ($\sqrt{s}$ = 10.866 GeV), collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. From the peak sample, the products of Born cross section times branching fraction are obtained for $σ_{\rm Born}(e^+e^-\toΥ_J(1D)η)$ or $σ_{\rm Born}(e^+e^-\toΥ_J(1D)π^+π^-)$ and ${\cal B}(Υ_J(1D)\toχ_{b1}γ)$ or ${\cal B}(Υ_J(1D)\toχ_{b2}γ)$ for each $Υ_J(1D)$ state. The corresponding branching fractions for $Υ(10860)$ decays are also obtained. The significances of the $Υ_1(1D)$, $Υ_2(1D)$, and $Υ_3(1D)$ signals are 4.8$σ$, ${>}10σ$, and 3.0$σ$, respectively, including systematic uncertainties. The mass for $Υ_2(1D)$ is measured to be $(10167.0\pm 1.0\pm 0.2)$ MeV/$c^2$, where the first and second uncertainties are statistical and systematic. The mass splittings $Δm_{12}=m(Υ_2(1D))-m(Υ_1(1D))$ and $Δm_{23}=m(Υ_3(1D))-m(Υ_2(1D))$ are $(11.8\pm1.5\pm0.4)$ MeV/$c^2$ and $(7.6\pm2.4\pm0.6)$ MeV/$c^2$, respectively.~We determine the energy dependence of the cross sections for $e^+e^-\toΥ_J(1D)η$ and $e^+e^-\toΥ_J(1D)π^+π^-$ for the $Υ_1(1D)$, $Υ_2(1D)$, and $Υ_3(1D)$ states, combined. △ Less

Submitted 5 July, 2026; originally announced July 2026.

Comments: 12 pages, 7 figures

Report number: Belle II Preprint 2026-014; KEK Preprint 2026-10

CJ26 Global QCD Analysis with Large-$x$ Jefferson Lab 6 and 12 GeV Data

Authors: Alberto Accardi, Matteo Cerutti, Cynthia E. Keppel, Shujie Li, J. F. Owens, Sanghwa Park, Peter Risse

Abstract: We present CJ26, the new CTEQ-JLab global QCD analysis that incorporates for the first time the complete suite of JLab 6 GeV DIS measurements and the first published JLab 12 GeV measurements. Focused on the large-$x$ region, the analysis utilizes the increased $Q^2$ leverage of the 12 GeV data to uniquely disentangle higher-twist effects from off-shell nucleon corrections. This leads to a highly a… ▽ More We present CJ26, the new CTEQ-JLab global QCD analysis that incorporates for the first time the complete suite of JLab 6 GeV DIS measurements and the first published JLab 12 GeV measurements. Focused on the large-$x$ region, the analysis utilizes the increased $Q^2$ leverage of the 12 GeV data to uniquely disentangle higher-twist effects from off-shell nucleon corrections. This leads to a highly accurate determination of the $n/p$ structure function ratio and the $d/u$ valence quark ratio, with uncertainties reduced by 30-50% and 5-10%, respectively. We highlight the critical role of experimental correlated systematic uncertainties in achieving this precision and provide the resulting NLO PDFs and structure functions in LHAPDF format for general use. △ Less

Submitted 29 May, 2026; originally announced May 2026.

Comments: Feedback welcome. Results available in LHAPDF format on CJ website: https://www.jlab.org/theory/cj/pdfs

Report number: JLAB-THY-26-4768, SMU-PHY-25-07

Confinement transition to gravitational waves in the one-flavor $SU(4)$ Hyper Stealth Dark Matter theory

Authors: V. Ayyar, R. C. Brower, G. T. Fleming, J. Ingoldby, X. Y. Jin, N. Matsumoto, A. S. Meyer, E. T. Neil, J. C. Osborn, S. Park, C. T. Peterson, D. Schaich, P. Vranas, O. Witzel

Abstract: The thermodynamics of the $SU(4)$ gauge theory with a single flavor of fundamental quarks is analyzed on the lattice with dynamical fermion simulations, which is the low-energy sector of a realistic, strongly-interacting dark matter model -- the Hyper Stealth Dark Matter. The gravitational wave spectrum from the first-order confinement transition in the early universe is further calculated, where… ▽ More The thermodynamics of the $SU(4)$ gauge theory with a single flavor of fundamental quarks is analyzed on the lattice with dynamical fermion simulations, which is the low-energy sector of a realistic, strongly-interacting dark matter model -- the Hyper Stealth Dark Matter. The gravitational wave spectrum from the first-order confinement transition in the early universe is further calculated, where the effect of the dark sea quarks, which decrease the interface tension in the effective potential of the Polyakov loop, is shown numerically to lower the gravitational wave amplitude. △ Less

Submitted 26 February, 2026; originally announced February 2026.

Comments: 11 pages, 15 figures

Report number: FERMILAB-PUB-26-0104-T, IPPP/26/17, SI-HEP-2026-02

Aspects of Sommerfeld Enhancement in the light of Halo gamma-ray excess

Authors: Yongsoo Jho, Jeonghwan Park, Min Gi Park, Seong Chan Park

Abstract: We examine Sommerfeld enhancement in dark matter annihilation as a potential origin of the halo-like gamma-ray excess near $E_γ\simeq 20$ GeV reported by Totani. A minimal model with a light CP-even scalar mediator naturally produces a velocity-dependent annihilation cross section consistent with thermal freeze-out, the Milky Way excess, and limits from dwarf spheroidal galaxies. We examine Sommerfeld enhancement in dark matter annihilation as a potential origin of the halo-like gamma-ray excess near $E_γ\simeq 20$ GeV reported by Totani. A minimal model with a light CP-even scalar mediator naturally produces a velocity-dependent annihilation cross section consistent with thermal freeze-out, the Milky Way excess, and limits from dwarf spheroidal galaxies. △ Less

Submitted 31 December, 2025; originally announced December 2025.

Comments: 5 pages, 4 figures

Probing hard/soft factorization via beam-spin asymmetry in exclusive pion electroproduction from the proton

Authors: Alicia C. Postuma, Garth M. Huber, D. J. Gaskell, N. Heinrich, T. Horn, M. Junaid, S. J. D. Kay, V. Kumar, P. Markowitz, J. Roche, R. Trotta, A. Usman, B. -G. Yu, T. K. Choi, K. -J. Kong, S. Ali, R. Ambrose, D. Androic, W. Armstrong, A. Bandari, V. Berdnikov, H. Bhatt, D. Bhetuwal, D. Biswas, M. Boer , et al. (54 additional authors not shown)

Abstract: Deep exclusive meson production (DEMP) reactions, such as $p(\vec{e},e'π^+)n$, provide opportunities to study the three-dimensional structure of the nucleon through differential cross section and beam- and target-spin asymmetry measurements. This work aims to probe the onset of the hard/soft factorization regime through the exclusive $p(\vec{e},e'π^+)n$ reaction, as measured in the KaonLT experime… ▽ More Deep exclusive meson production (DEMP) reactions, such as $p(\vec{e},e'π^+)n$, provide opportunities to study the three-dimensional structure of the nucleon through differential cross section and beam- and target-spin asymmetry measurements. This work aims to probe the onset of the hard/soft factorization regime through the exclusive $p(\vec{e},e'π^+)n$ reaction, as measured in the KaonLT experiment at Jefferson Lab Hall C. A 10.6 GeV longitudinally polarized electron beam was incident on an unpolarized liquid hydrogen target, and the scattered electron and produced meson were detected in two magnetic focusing spectrometers, enabling precision cross section measurements. The cross section ratio $σ_{LT'}/σ_0$ was extracted from the beam-spin asymmetry $A_{LU}$. The $t$-dependence of $σ_{LT'}/σ_0$ was determined at fixed $Q^2$ and $x_B$ over a range of kinematics from $2<Q^2<6$ GeV$^2$ above the resonance region ($W>2$ GeV). Furthermore, these data are combined with recent results from CLAS/CLAS12 to determine the $Q^2$-dependence of $σ_{LT'}/σ_0$ at two ($x_B$, $t$) settings. This was fairly flat, with $Q^2$ not having a measurable effect on the value of $σ_{LT'}/σ_0$ in the range explored. Results are compared to predictions from the generalized parton distribution (GPD) formalism, which relies explicitly on hard/soft factorization, and Regge formalism. The Regge models better predict $σ_{LT'}/σ_0$, which suggests that the factorization regime is not yet reached. △ Less

Submitted 1 December, 2025; originally announced December 2025.

Comments: 9 pages, 7 figures, 2 tables (main text) plus 3 pages, 6 figures, 1 table (supplemental material / appendices)

Journal ref: Phys. Lett. B 872 (2026) 140094

Finite-temperature stability from doublet inflation field with right-handed neutrinos

Authors: Seong Chan Park, Shilpa Jangid

Abstract: We study the augmentation of the Standard Model (SM) with another $SU(2)$ Higgs doublet and right-handed neutrinos. The second Higgs doublet ($Φ_2$) is defined to be odd under the $Z_2$ symmetry, and hence, the lightest stable neutral particle from the additional doublet becomes the cold dark matter candidate. The right-handed neutrino field coupled to the Higgs field provides non-zero mass for th… ▽ More We study the augmentation of the Standard Model (SM) with another $SU(2)$ Higgs doublet and right-handed neutrinos. The second Higgs doublet ($Φ_2$) is defined to be odd under the $Z_2$ symmetry, and hence, the lightest stable neutral particle from the additional doublet becomes the cold dark matter candidate. The right-handed neutrino field coupled to the Higgs field provides non-zero mass for the neutrinos. The inert doublet field coupled non-minimally to gravity as $ζ_2 Φ_2^\dagger Φ_2 R$ also acts as an inflaton field. The inflationary bounds restrict the interaction couplings as $λ_2/ζ_2^2 \approx 4\times 10^{-10}$. After inflation ends, the scalar bosonic degrees of freedom from the inert doublet can contribute to the electroweak phase transition. The strongly first-order phase transition bound, i.e., $\frac{φ_{+}(T_c)}{T_c} \geq 1.0$ restricts the bare mass parameter of the additional doublet to $m_{22}=400.0$ GeV, demanding GUT scale perturbative unitarity for $Y_N=0.01$. The increase in $Y_N$ reduces the strength of phase transition, and it is no longer satisfied even for vanishing bare mass parameter. The Planck scale perturbative unitarity allows for the first-order phase transition, $\frac{φ_{+}(T_c)}{T_c} \geq 0.6$, until $m_{22}=70.0$ GeV for $Y_N=0.01$, and none of the mass values satisfies the first-order phase transition for $Y_N=0.4$. The thermal corrections also affect the probability of tunneling from the false vacuum to the true vacuum, and hence, the finite temperature stability of the electroweak vacuum has been studied, including the finite-temperature effects. △ Less

Submitted 31 January, 2026; v1 submitted 28 September, 2025; originally announced September 2025.

Comments: 23 pages, 20 figures

Journal ref: Prog. Theor. Exp. Phys. 2026, ptag021

Beyond the Starobinsky model after ACT

Authors: Min Gi Park, Dhong Yeon Cheong, Seong Chan Park

Abstract: We revisit higher order corrections to the Starobinsky inflationary model using the most recent P-ACT-LB-BK18 data, which exhibits a mild but definite tension with the predictions of the original model. Our results demonstrate how even small {higher order} deformations of the Ricci scalar (e.g. $R^3, R^4,\cdots$) can bring the model into better agreement with current data and impose nontrivial con… ▽ More We revisit higher order corrections to the Starobinsky inflationary model using the most recent P-ACT-LB-BK18 data, which exhibits a mild but definite tension with the predictions of the original model. Our results demonstrate how even small {higher order} deformations of the Ricci scalar (e.g. $R^3, R^4,\cdots$) can bring the model into better agreement with current data and impose nontrivial constraints on the post-inflationary dynamics. △ Less

Submitted 20 February, 2026; v1 submitted 4 September, 2025; originally announced September 2025.

Comments: 6 pages, 5 figures

Journal ref: Physics Letters B, Volume 873, 2026, 140217

Composite Hybrid Inflation : Primordial Black Holes and Stochastic Gravitational Waves

Authors: Giacomo Cacciapaglia, Dhong Yeon Cheong, Aldo Deandrea, Wanda Isnard, Seong Chan Park, Xinpeng Wang, Ying-li Zhang

Abstract: We investigate the production of primordial black holes and gravitational waves in composite hybrid inflation. Starting from an effective chiral Lagrangian with a dilaton and pions, we identify inflation occurring due to the walking dynamics of the theory. A $\mathbb{Z}_2$ symmetry-breaking term in the pion sector induces a shift in the inflaton's trajectory, which leads to a tachyonic instability… ▽ More We investigate the production of primordial black holes and gravitational waves in composite hybrid inflation. Starting from an effective chiral Lagrangian with a dilaton and pions, we identify inflation occurring due to the walking dynamics of the theory. A $\mathbb{Z}_2$ symmetry-breaking term in the pion sector induces a shift in the inflaton's trajectory, which leads to a tachyonic instability phase. Curvature perturbations grow exponentially, producing copious primordial black holes and a stochastic gravitational wave background. We show that the primordial black hole mass and the gravitational wave frequency are strongly restricted by the anomalous dimensions of the pion operators, with larger anomalous dimensions giving lighter primordial black holes and higher frequency gravitational waves. In both cases, the associated signatures lie within reach of future gravitational wave observatories. △ Less

Submitted 22 March, 2026; v1 submitted 7 June, 2025; originally announced June 2025.

Comments: 29 pages, 17 figures, matches JCAP version

Strongly electroweak phase transition with $U(1)_{L_μ-L_τ}$ gauged non-zero hypercharge triplet

Authors: Shilpa Jangid, Anirban Biswas, Seong Chan Park

Abstract: This article considers three non-zero hypercharge triplets as an extension of the Standard Model Higgs doublet. Under extra $U(1)_{L_μ-L_τ}$ symmetry, the triplets are charged. We examine the stability of the electroweak vacuum at the two-loop and tree-levels. The two-loop $β$-functions are found to be capable of satisfying the vacuum stability up to the Planck scale. On the other hand, only up to… ▽ More This article considers three non-zero hypercharge triplets as an extension of the Standard Model Higgs doublet. Under extra $U(1)_{L_μ-L_τ}$ symmetry, the triplets are charged. We examine the stability of the electroweak vacuum at the two-loop and tree-levels. The two-loop $β$-functions are found to be capable of satisfying the vacuum stability up to the Planck scale. On the other hand, only up to $10^{12}$ GeV can the perturbative unitarity be satisfied because of the increase in the positive influence from triplet degrees of freedom. For the strongly electroweak first-order phase transition, the parameter space permitted by the Planck scale stability is examined. Because the triplet degrees of freedom contribute sufficiently to the cubic term, the model satisfies the strongly first order phase transition for the triplet bare mass parameters up to the TeV scale. For all mass ranges, it is found that this model predicts a strongly first-order phase transition until the degrees of freedom are heavy enough to separate from the thermal bath. The gravitational wave signatures are tested at the benchmark places that fulfill the strongly first-order phase transition. The measurable frequency range of the LISA and BBO experiments also turns out to contain the benchmark points permitted by Planck scale stability, strongly first-order phase transition. △ Less

Submitted 26 January, 2026; v1 submitted 15 April, 2025; originally announced April 2025.

Comments: 31 pages, 13 figures

Journal ref: Prog Theor Exp Phys (2026)

Investigating two-zero texture in the light of gauged Type-II seesaw

Authors: Anirban Biswas, Shilpa Jangid, Seong Chan Park

Abstract: Neutrino oscillation, discovered over two decades ago, confirmed that neutrinos have nonzero masses. Since then, two mass-squared differences have been measured with unprecedented precision, yet the absolute neutrino mass scale remains unknown. Additionally, the fundamental symmetry governing the neutrino mixing pattern is still undetermined. Among various theoretical possibilities, the two-zero t… ▽ More Neutrino oscillation, discovered over two decades ago, confirmed that neutrinos have nonzero masses. Since then, two mass-squared differences have been measured with unprecedented precision, yet the absolute neutrino mass scale remains unknown. Additionally, the fundamental symmetry governing the neutrino mixing pattern is still undetermined. Among various theoretical possibilities, the two-zero texture in the neutrino mass matrix ($m_ν$) stands out as an attractive framework due to its reduced number of free parameters, enabling definite predictions for the unknown parameters of the PMNS matrix. In this work, we present a comprehensive analysis of the two-zero texture, focusing on its implications for the Dirac CP phase ($δ$), the Majorana phases ($ρ$, $σ$) and the effective Majorana mass ($m_{ββ}$), the latter being crucial for neutrinoless double beta decay. We find that for certain two-zero textures, $m_{ββ}$ reaches a few tens of meV, placing it within the sensitivity range of KamLAND-Zen. Furthermore, we demonstrate how a two-zero texture can naturally emerge in a well-motivated neutrino mass model, specifically the gauged Type-II seesaw mechanism, which requires multiple scalar triplets. Notably, some of the two-zero patterns cannot be realized in this framework, as more than two independent zeros appear in $m_ν$. Finally, we discuss key phenomenological consequences of the gauged Type-II seesaw model. △ Less

Submitted 6 August, 2025; v1 submitted 14 April, 2025; originally announced April 2025.

Comments: 18 pages, 3 figures, 3 tables, new references added, version published in Physics Letters B

Journal ref: Phys. Lett. B 868 (2025) 139786

A Linear Collider Vision for the Future of Particle Physics

Authors: H. Abramowicz, E. Adli, F. Alharthi, M. Almanza-Soto, M. M. Altakach, W. Altmannshofer, S. Ampudia Castelazo, D. Angal-Kalinin, J. A. Anguiano, R. B. Appleby, O. Apsimon, A. Arbey, F. Arco, O. Arquero, A. Aryshev, S. Asai, D. Attie, J. L. Avila-Jimenez, H. Baer, J. A. Bagger, Y. Bai, I. R. Bailey, C. Balazs, P. Bambade, T. Barklow , et al. (426 additional authors not shown)

Abstract: In this paper we review the physics opportunities at linear $e^+e^-$ colliders with a special focus on high centre-of-mass energies and beam polarisation, take a fresh look at the various accelerator technologies available or under development and, for the first time, discuss how a facility first equipped with a technology mature today could be upgraded with technologies of tomorrow to reach much… ▽ More In this paper we review the physics opportunities at linear $e^+e^-$ colliders with a special focus on high centre-of-mass energies and beam polarisation, take a fresh look at the various accelerator technologies available or under development and, for the first time, discuss how a facility first equipped with a technology mature today could be upgraded with technologies of tomorrow to reach much higher energies and/or luminosities. In addition, we will discuss detectors and alternative collider modes, as well as opportunities for beyond-collider experiments and R\&D facilities as part of a linear collider facility (LCF). The material of this paper will support all plans for $e^+e^-$ linear colliders and additional opportunities they offer, independently of technology choice or proposed site, as well as R\&D for advanced accelerator technologies. This joint perspective on the physics goals, early technologies and upgrade strategies has been developed by the LCVision team based on an initial discussion at LCWS2024 in Tokyo and a follow-up at the LCVision Community Event at CERN in January 2025. It heavily builds on decades of achievements of the global linear collider community, in particular in the context of CLIC and ILC. △ Less

Submitted 23 December, 2025; v1 submitted 25 March, 2025; originally announced March 2025.

Comments: Community document for EPPSU, major updates of several sections, in particular the global interpretation section

Superheavy Supersymmetric Dark Matter for the origin of KM3NeT Ultra-High Energy signal

Authors: Yongsoo Jho, Seong Chan Park, Chang Sub Shin

Abstract: We propose an explanation for the recently reported ultra-high-energy neutrino signal at KM3NeT, which shows no clear association with known astrophysical sources. While decaying dark matter in the Galactic Center is a natural candidate, the observed arrival direction strongly suggests an extragalactic origin. We introduce a multicomponent dark matter scenario in which the components are part of a… ▽ More We propose an explanation for the recently reported ultra-high-energy neutrino signal at KM3NeT, which shows no clear association with known astrophysical sources. While decaying dark matter in the Galactic Center is a natural candidate, the observed arrival direction strongly suggests an extragalactic origin. We introduce a multicomponent dark matter scenario in which the components are part of a supermultiplet, with supersymmetry ensuring a nearly degenerate mass spectrum among the fields with different spins. In this setup, a cosmologically long-lived fermionic state decays into a slightly lighter bosonic dark matter state, producing a boosted neutrino spectrum with energy $E_ν\sim 100$ PeV, determined by the mass difference. The heavy-to-light decay occurs at a cosmological redshift of $z \sim \text{a few}$ or higher, leading to an isotropic directional distribution of the signal. △ Less

Submitted 9 December, 2025; v1 submitted 24 March, 2025; originally announced March 2025.

Comments: 9 pages, 3 figures, version accepted by PRD

Journal ref: Phys.Rev.D 112 (2025) 11, 115004

Measurements of the branching fractions of $Ξ_{c}^{+}\to Σ^{+}K_{S}^{0}$, $Ξ_{c}^{+}\to Ξ^{0}π^{+}$, and $Ξ_{c}^{+}\to Ξ^{0}K^{+}$ at Belle and Belle II

Authors: Belle, Belle II Collaborations, :, I. Adachi, J. K. Ahn, Y. Ahn, N. Akopov, S. Alghamdi, M. Alhakami, N. Althubiti, K. Amos, N. Anh Ky, C. Antonioli, D. M. Asner, M. Aversano, R. Ayad, V. Babu, N. K. Baghel, P. Bambade, Sw. Banerjee, M. Barrett, M. Bartl, J. Baudot, A. Beaubien, F. Becherer , et al. (335 additional authors not shown)

Abstract: Using 983.0 $\rm{fb}^{-1}$ and 427.9 $\rm{fb}^{-1}$ data samples collected with the Belle and Belle II detectors at the KEKB and SuperKEKB asymmetric energy $e^+e^-$ colliders, respectively, we present studies of the Cabibbo-favored $Ξ_c^+$ decays ${Ξ_{c}^{+}\to Σ^{+}K_{S}^{0}}$ and $Ξ_{c}^{+}\to Ξ^{0}π^{+}$, and the singly Cabibbo-suppressed decay $Ξ_{c}^{+}\to Ξ^{0}K^{+}$. The ratios of branchin… ▽ More Using 983.0 $\rm{fb}^{-1}$ and 427.9 $\rm{fb}^{-1}$ data samples collected with the Belle and Belle II detectors at the KEKB and SuperKEKB asymmetric energy $e^+e^-$ colliders, respectively, we present studies of the Cabibbo-favored $Ξ_c^+$ decays ${Ξ_{c}^{+}\to Σ^{+}K_{S}^{0}}$ and $Ξ_{c}^{+}\to Ξ^{0}π^{+}$, and the singly Cabibbo-suppressed decay $Ξ_{c}^{+}\to Ξ^{0}K^{+}$. The ratios of branching fractions of ${Ξ_{c}^{+}\to Σ^{+}K_{S}^{0}}$ and $Ξ_{c}^{+}\to Ξ^{0}K^{+}$ relative to that of $Ξ_{c}^{+}\toΞ^{-}π^{+}π^{+}$ are measured for the first time, while the ratio ${\cal B}(Ξ_{c}^{+}\toΞ^{0}π^{+})/{\cal B}(Ξ_{c}^{+}\toΞ^{-}π^{+}π^{+}) $ is also determined and improved by an order of magnitude in precision. The measured branching fraction ratios are $\frac{\cal{B}(Ξ_{c}^{+} \to Σ^{+}K_{S}^{0})}{\cal{B}(Ξ_{c}^{+}\to Ξ^{-}π^{+}π^+)}= 0.067 \pm 0.007 \pm 0.003$, $\frac{\cal{B}(Ξ_c^{+} \to Ξ^{0}π^{+})}{\cal{B}(Ξ_{c}^{+}\to Ξ^{-}π^{+}π^+)} = 0.251 \pm 0.005 \pm 0.010$, $\frac{\cal{B}(Ξ_c^{+} \to Ξ^{0}K^{+})}{\cal{B}(Ξ_{c}^{+}\to Ξ^{-}π^{+}π^+)} = 0.017 \pm 0.003 \pm 0.001$. Additionally, the ratio ${\cal B}(Ξ_{c}^{+}\toΞ^{0}K^{+})/{\cal B}(Ξ_{c}^{+}\toΞ^{0}π^{+})$ is measured to be $ 0.068 \pm 0.010 \pm 0.004$. Here, the first and second uncertainties are statistical and systematic, respectively. Multiplying the ratios by the branching fraction of the normalization mode, ${\mathcal B}(Ξ_{c}^{+}\toΞ^{-}π^{+}π^+)= (2.9\pm 1.3)\%$, we obtain the following absolute branching fractions ${\cal B}(Ξ_{c}^{+}\toΣ^{+}K^{0}_{S}) = (0.194 \pm 0.021 \pm 0.009 \pm 0.087 )%$, ${\cal B}(Ξ_{c}^{+}\toΞ^{0}π^{+}) = (0.728 \pm 0.014 \pm 0.027 \pm 0.326 )%$, ${\cal B}(Ξ_{c}^{+}\toΞ^{0}K^{+}) = (0.049 \pm 0.007 \pm 0.003 \pm 0.022 )%$. △ Less

Submitted 29 July, 2025; v1 submitted 22 March, 2025; originally announced March 2025.

Comments: 20 pages, 4 figures, 3 Tables; accepted for publication in JHEP

Report number: Belle II Preprint 2025-005; KEK Preprint 2025-2

Journal ref: JHEP08(2025)195

2025 update on $\varepsilon_K$ in the Standard Model with lattice QCD inputs

Authors: Seungyeob Jwa, Jeehun Kim, Sunghee Kim, Sunkyu Lee, Weonjong Lee, Sungwoo Park

Abstract: We present theoretical results for the indirect CP violation parameter, $ |\varepsilon_K| $, evaluated directly within the Standard Model using lattice QCD inputs including $ B_K $, $ |V_{cb}| $, $ |V_{us}| $, $ |V_{ud}| $, $ ξ_0 $, $ ξ_2 $, $ F_K $, and the charm quark mass $ m_c $. Our analysis reveals a significant tension at the $ \sim 5σ$ level ($ 4.6σ$ to $ 5.2σ$) between the Standard Model… ▽ More We present theoretical results for the indirect CP violation parameter, $ |\varepsilon_K| $, evaluated directly within the Standard Model using lattice QCD inputs including $ B_K $, $ |V_{cb}| $, $ |V_{us}| $, $ |V_{ud}| $, $ ξ_0 $, $ ξ_2 $, $ F_K $, and the charm quark mass $ m_c $. Our analysis reveals a significant tension at the $ \sim 5σ$ level ($ 4.6σ$ to $ 5.2σ$) between the Standard Model prediction and the experimental value of $ |\varepsilon_K| $. The Standard Model prediction, informed by lattice QCD inputs, accounts for only approximately 65% of the experimental value, leaving a 35% discrepancy unexplained. Notably, this tension vanishes when using the inclusive determination of $ |V_{cb}| $, derived from heavy quark expansion. The discrepancy is therefore tied to the well-known tension between the exclusive and inclusive determinations of $ |V_{cb}| $. We further report results for $ |\varepsilon_K| $ obtained using the Brod--Gorbahn--Stamou (BGS) method based on $ u\text{--}t $ unitarity, which yields an even stronger discrepancy, in the range of $ 4.9σ$ to $ 5.5σ$, when combined with lattice QCD inputs. △ Less

Submitted 15 July, 2025; v1 submitted 28 February, 2025; originally announced March 2025.

Comments: 21 pages, 15 figures, references updated. arXiv admin note: text overlap with arXiv:1808.09657

Gradient flow of the Weinberg operator

Authors: Tanmoy Bhattacharya, Shohini Bhattacharya, Vincenzo Cirigliano, Rajan Gupta, Emanuele Mereghetti, Sungwoo Park, Jun-Sik Yoo, Boram Yoon

Abstract: We present preliminary results on the susceptibilities involving the CP-violating (CPV) Weinberg three-gluon operator and the topological $Θ$ term using the gradient flow scheme, and study their continuum and chiral extrapolations. These are used to provide an estimate of the $Θ$ induced by the Weinberg operator in theories with the Peccei-Quinn (PQ) mechanism. Combined with the calculations of th… ▽ More We present preliminary results on the susceptibilities involving the CP-violating (CPV) Weinberg three-gluon operator and the topological $Θ$ term using the gradient flow scheme, and study their continuum and chiral extrapolations. These are used to provide an estimate of the $Θ$ induced by the Weinberg operator in theories with the Peccei-Quinn (PQ) mechanism. Combined with the calculations of the matrix elements (MEs) of quark-bilinears between nucleon states, such calculations will enable estimates of the electric dipole moments (EDMs) and CPV pion-nucleon couplings due to the Weinberg operator, thereby providing robust constraints on beyond the standard model (BSM) physics. △ Less

Submitted 1 February, 2025; originally announced February 2025.

Comments: 11 pages, 2 figures

Report number: LA-UR-24-29084

Systematic uncertainties from higher-twist corrections in DIS at large x

Authors: Matteo Cerutti, Alberto Accardi, Ishara P. Fernando, Shujie Li, Joseph F. Owens, Sanghwa Park

Abstract: We investigate the systematic uncertainties and potential biases arising from the inclusion of large-$x$ corrections to proton and deuteron deep inelastic scattering (DIS) data in global quantum chromodynamics (QCD) analyses. Using the CTEQ-JLab framework, we examine various approaches to implementing higher-twist corrections in nucleon structure functions and off-shell PDF modifications in deuter… ▽ More We investigate the systematic uncertainties and potential biases arising from the inclusion of large-$x$ corrections to proton and deuteron deep inelastic scattering (DIS) data in global quantum chromodynamics (QCD) analyses. Using the CTEQ-JLab framework, we examine various approaches to implementing higher-twist corrections in nucleon structure functions and off-shell PDF modifications in deuteron targets. We analyze how these components interact and influence the determination of the $d$-quark PDF and the neutron structure function at large $x$. We find that it is very important to consider isospin-dependent higher-twist corrections in order to minimize implementation biases in the extracted quantities. △ Less

Submitted 14 May, 2025; v1 submitted 12 January, 2025; originally announced January 2025.

Comments: Minor changes to match published version

Report number: JLAB-THY-25-7

Journal ref: Phys. Rev. D 111 (2025) 9, 094013

Gravitational waves from a first-order phase transition of the inflaton

Authors: Jörn Kersten, Seong Chan Park, Yeji Park, Juhoon Son, Liliana Velasco-Sevilla

Abstract: We explore the production of gravitational waves (GW) resulting from a first-order phase transition (FOPT) in a non-minimally coupled `Dark Higgs Inflation' model. Utilizing a dark sector scalar field as the inflaton, we demonstrate how inflationary dynamics naturally set the stage for observable FOPT. These transitions, influenced by thermal and quantum effects, generate GW spectra potentially de… ▽ More We explore the production of gravitational waves (GW) resulting from a first-order phase transition (FOPT) in a non-minimally coupled `Dark Higgs Inflation' model. Utilizing a dark sector scalar field as the inflaton, we demonstrate how inflationary dynamics naturally set the stage for observable FOPT. These transitions, influenced by thermal and quantum effects, generate GW spectra potentially detectable by observatories such as LISA, DECIGO, the Cosmic Explorer and the Einstein Telescope. Our study highlights the inflaton's dual role in cosmic inflation and early Universe phase transitions, presenting a unified framework to probe physics beyond the Standard Model through gravitational wave astronomy. △ Less

Submitted 22 December, 2024; originally announced December 2024.

Comments: 24 pages, 9 figures

Report number: CQUeST-2024-0752

Journal ref: JCAP04(2025) 053

Machine Learning-Assisted Measurement of Lepton-Jet Azimuthal Angular Asymmetries in Deep-Inelastic Scattering at HERA

Authors: The H1 collaboration, V. Andreev, M. Arratia, A. Baghdasaryan, A. Baty, K. Begzsuren, A. Bolz, V. Boudry, G. Brandt, D. Britzger, A. Buniatyan, L. Bystritskaya, A. J. Campbell, K. B. Cantun Avila, K. Cerny, V. Chekelian, Z. Chen, J. G. Contreras, J. Cvach, J. B. Dainton, K. Daum, A. Deshpande, C. Diaconu, A. Drees, G. Eckerlin , et al. (119 additional authors not shown)

Abstract: In deep-inelastic positron-proton scattering, the lepton-jet azimuthal angular asymmetry is measured using data collected with the H1 detector at HERA. When the average transverse momentum of the lepton-jet system, $\lvert \vec{P}_\perp \rvert $, is much larger than the total transverse momentum of the system, $\lvert \vec{q}_\perp \rvert$, the asymmetry between parallel and antiparallel configura… ▽ More In deep-inelastic positron-proton scattering, the lepton-jet azimuthal angular asymmetry is measured using data collected with the H1 detector at HERA. When the average transverse momentum of the lepton-jet system, $\lvert \vec{P}_\perp \rvert $, is much larger than the total transverse momentum of the system, $\lvert \vec{q}_\perp \rvert$, the asymmetry between parallel and antiparallel configurations, $\vec{P}_\perp$ and $\vec{q}_\perp$, is expected to be generated by initial and final state soft gluon radiation and can be predicted using perturbation theory. Quantifying the angular properties of the asymmetry therefore provides an additional test of the strong force. Studying the asymmetry is important for future measurements of intrinsic asymmetries generated by the proton's constituents through Transverse Momentum Dependent (TMD) Parton Distribution Functions (PDFs), where this asymmetry constitutes a dominant background. Moments of the azimuthal asymmetries are measured using a machine learning method for unfolding that does not require binning. △ Less

Submitted 21 December, 2024; v1 submitted 18 December, 2024; originally announced December 2024.

Comments: 15 pages, 4 figures, 2 tables, updated affiliations and acknowledgements

Report number: DESY24-200

Observations of the singly Cabibbo-suppressed decays $Ξ_c^{+} \to pK_{S}^{0}$, $Ξ_c^+ \to Λπ^+$, and $Ξ_c^+ \to Σ^{0} π^+$ at Belle and Belle II

Authors: Belle, Belle II Collaborations, :, I. Adachi, L. Aggarwal, N. Akopov, M. Alhakami, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, N. K. Baghel, S. Bahinipati, P. Bambade, Sw. Banerjee, M. Barrett, J. Baudot, A. Baur, A. Beaubien , et al. (323 additional authors not shown)

Abstract: Using data samples of 983.0~$\rm fb^{-1}$ and 427.9~$\rm fb^{-1}$ accumulated with the Belle and Belle~II detectors operating at the KEKB and SuperKEKB asymmetric-energy $e^+e^-$ colliders, singly Cabibbo-suppressed decays $Ξ_c^{+} \to pK_{S}^{0}$, $Ξ_c^+ \to Λπ^+$, and $Ξ_c^+ \to Σ^{0} π^+$ are observed for the first time. The ratios of branching fractions of $Ξ_{c}^{+}\to p K_{S}^{0}$,… ▽ More Using data samples of 983.0~$\rm fb^{-1}$ and 427.9~$\rm fb^{-1}$ accumulated with the Belle and Belle~II detectors operating at the KEKB and SuperKEKB asymmetric-energy $e^+e^-$ colliders, singly Cabibbo-suppressed decays $Ξ_c^{+} \to pK_{S}^{0}$, $Ξ_c^+ \to Λπ^+$, and $Ξ_c^+ \to Σ^{0} π^+$ are observed for the first time. The ratios of branching fractions of $Ξ_{c}^{+}\to p K_{S}^{0}$, $Ξ_{c}^{+}\to Λπ^{+}$, and $Ξ_{c}^{+}\to Σ^{0} π^{+}$ relative to that of $Ξ_c^+ \to Ξ^- π^{+} π^{+}$ are measured to be \begin{equation} \frac{{\cal B}(Ξ_c^+ \to pK_S^0)}{{\cal B}(Ξ_c^{+} \to Ξ^{-} π^+ π^+)} = (2.47 \pm 0.16 \pm 0.07)\% \notag, \end{equation} \begin{equation} \frac{{\cal B}(Ξ_c^+ \to Λπ^+)}{{\cal B}(Ξ_c^{+} \to Ξ^{-} π^+ π^+)} = (1.56 \pm 0.14 \pm 0.09)\% \notag, \end{equation} \begin{equation} \frac{{\cal B}(Ξ_c^+ \to Σ^0 π^+)}{{\cal B}(Ξ_c^{+} \to Ξ^{-} π^+ π^+)} = (4.13 \pm 0.26 \pm 0.22)\% \notag. \end{equation} Multiplying these values by the branching fraction of the normalization channel, ${\cal B}(Ξ_c^{+} \to Ξ^{-} π^+π^+) = (2.9 \pm 1.3)\%$, the absolute branching fractions are determined to be \begin{equation} {\cal B}(Ξ_c^{+} \to p K_{S}^{0}) = (7.16 \pm 0.46 \pm 0.20 \pm 3.21) \times 10^{-4} \notag, \end{equation} \begin{equation} {\cal B}(Ξ_c^{+} \to Λπ^+) = (4.52 \pm 0.41 \pm 0.26 \pm 2.03) \times 10^{-4} \notag, \end{equation} \begin{equation} {\cal B}(Ξ_c^{+} \to Σ^0 π^+) = (1.20 \pm 0.08 \pm 0.07 \pm 0.54) \times 10^{-3} \notag. \end{equation} The first and second uncertainties above are statistical and systematic, respectively, while the third ones arise from the uncertainty in ${\cal B}(Ξ_c^{+} \to Ξ^{-} π^{+} π^{+})$. △ Less

Submitted 13 December, 2024; originally announced December 2024.

Comments: 21 pages, 5 pages

Report number: Belle II Preprint 2024-028; KEK Preprint 2024-29

Journal ref: JHEP03(2025)061

Non-minimally coupled quintessential inflation

Authors: Seong Chan Park

Abstract: We present a unified framework that simultaneously addresses the dynamics of early-time cosmic inflation and late-time cosmic acceleration within the context of a single scalar field non-minimally coupled to gravity. By employing an exponential coupling function and a scalar potential with dual asymptotic plateaus, our model naturally transitions from inflationary dynamics at small field values to… ▽ More We present a unified framework that simultaneously addresses the dynamics of early-time cosmic inflation and late-time cosmic acceleration within the context of a single scalar field non-minimally coupled to gravity. By employing an exponential coupling function and a scalar potential with dual asymptotic plateaus, our model naturally transitions from inflationary dynamics at small field values to a quintessence-like behavior at large field values. We derive the inflationary predictions for the spectral index ($n_s$) and tensor-to-scalar ratio ($r$) in agreement with current observational constraints. For late-time acceleration, the model produces a viable dark energy component with an equation of state $w_φ$ approaching $-1$ but retaining a measurable deviation that could serve as an observational signature. This work demonstrates that a single theoretical framework can reconcile both early inflation and the late-time accelerated expansion of the Universe. △ Less

Submitted 11 December, 2024; originally announced December 2024.

Comments: 8 pages, 3 figures

Journal ref: Progress of Theoretical and Experimental Physics, Volume 2025, Issue 10, October 2025, 103E02

Product Manifold Machine Learning for Physics

Authors: Nathaniel S. Woodward, Sang Eon Park, Gaia Grosso, Jeffrey Krupa, Philip Harris

Abstract: Physical data are representations of the fundamental laws governing the Universe, hiding complex compositional structures often well captured by hierarchical graphs. Hyperbolic spaces are endowed with a non-Euclidean geometry that naturally embeds those structures. To leverage the benefits of non-Euclidean geometries in representing natural data we develop machine learning on… ▽ More Physical data are representations of the fundamental laws governing the Universe, hiding complex compositional structures often well captured by hierarchical graphs. Hyperbolic spaces are endowed with a non-Euclidean geometry that naturally embeds those structures. To leverage the benefits of non-Euclidean geometries in representing natural data we develop machine learning on $\mathcal P \mathcal M$ spaces, Cartesian products of constant curvature Riemannian manifolds. As a use case we consider the classification of "jets", sprays of hadrons and other subatomic particles produced by the hadronization of quarks and gluons in collider experiments. We compare the performance of $\mathcal P \mathcal M$-MLP and $\mathcal P \mathcal M$-Transformer models across several possible representations. Our experiments show that $\mathcal P \mathcal M$ representations generally perform equal or better to fully Euclidean models of similar size, with the most significant gains found for highly hierarchical jets and small models. We discover significant correlation between the degree of hierarchical structure at a per-jet level and classification performance with the $\mathcal P \mathcal M$-Transformer in top tagging benchmarks. This is a promising result highlighting a potential direction for further improving machine learning model performance through tailoring geometric representation at a per-sample level in hierarchical datasets. These results reinforce the view of geometric representation as a key parameter in maximizing both performance and efficiency of machine learning on natural data. △ Less

Submitted 9 December, 2024; originally announced December 2024.

Wormhole-Induced ALP Dark Matter

Authors: Dhong Yeon Cheong, Koichi Hamaguchi, Yoshiki Kanazawa, Sung Mook Lee, Natsumi Nagata, Seong Chan Park

Abstract: Non-perturbative gravitational effects induce explicit global symmetry breaking terms within axion models. These exponentially suppressed terms in the potential give a mass contribution to the axion-like particles (ALPs). In this work we investigate this scenario with a scalar field charged under a global $U(1)$ symmetry and having a non-minimal coupling to gravity. Given the exponential dependenc… ▽ More Non-perturbative gravitational effects induce explicit global symmetry breaking terms within axion models. These exponentially suppressed terms in the potential give a mass contribution to the axion-like particles (ALPs). In this work we investigate this scenario with a scalar field charged under a global $U(1)$ symmetry and having a non-minimal coupling to gravity. Given the exponential dependence, the ALP can retain a mass spanning a wide range, which can act as a dark matter component. We specify pre-inflationary and post-inflationary production mechanisms of these ALPs, with the former from the misalignment mechanism and the latter from both the misalignment and cosmic-string decay. We identify the allowed parameter ranges that explain the dark matter abundance for both a general inflation case and a case where the radial mode scalar drives inflation, each in metric and Palatini formalisms. We show that the ALP can be the dominant component of the dark matter in a wide range of its mass, $m_{a} \in [10^{-21}~\mathrm{eV},\, \mathrm{TeV}]$, depending on the inflationary scenario and the $U(1)$ breaking scale. These results indicate that ALPs can be responsible for our dark matter abundance within a setup purely from non-perturbative gravitational effects. △ Less

Submitted 12 November, 2024; originally announced November 2024.

Comments: 25 pages, 5 figures, 1 table

Report number: CERN-TH-2024-195

Journal ref: JHEP 02 (2025) 183

Flavor Dependence of Charged Pion Fragmentation Functions

Authors: H. Bhatt, P. Bosted, S. Jia, W. Armstrong, D. Dutta, R. Ent, D. Gaskell, E. Kinney, H. Mkrtchyan, S. Ali, R. Ambrose, D. Androic, C. Ayerbe Gayoso, A. Bandari, V. Berdnikov, D. Bhetuwal, D. Biswas, M. Boer, E. Brash, A. Camsonne, J. P. Chen, J. Chen, M. Chen, E. M. Christy, S. Covrig , et al. (45 additional authors not shown)

Abstract: We have measured the flavor dependence of multiplicities for pi^+ and pi^- production in semi-inclusive deep-inelastic scattering (SIDIS) on proton and deuteron targets to explore a possible charge symmetry violation in fragmentation functions. The experiment used an electron beam with energies of 10.2 and 10.6 GeV at Jefferson Lab and the Hall-C spectrometers. The electron kinematics spanned the… ▽ More We have measured the flavor dependence of multiplicities for pi^+ and pi^- production in semi-inclusive deep-inelastic scattering (SIDIS) on proton and deuteron targets to explore a possible charge symmetry violation in fragmentation functions. The experiment used an electron beam with energies of 10.2 and 10.6 GeV at Jefferson Lab and the Hall-C spectrometers. The electron kinematics spanned the range 0.3<x<0.6, 2<Q^2<5.5 GeV^2, and 4<W^2<11 GeV^2. The pion fractional momentum range was 0.3< z <0.7, and the transverse momentum range was 0<p_T<0.25 GeV/c. Assuming factorization at low p_T and allowing for isospin breaking, we find that the results can be described by two "favored" and two "un-favored" effective low $p_T$ fragmentation functions that are flavor-dependent. However, they converge to a common flavor-independent value at the lowest x or highest W of this experiment. △ Less

Submitted 5 September, 2024; v1 submitted 29 August, 2024; originally announced August 2024.

Comments: 6 pages, 3 figures with 11 pages of supplementary material which has 9 figures

Search for charmed baryons in the $Λ_c^+η$ system and measurement of the branching fractions of $Λ_c(2880)^+$ and $Λ_c(2940)^+$ decaying to $Λ_c^+η$ and $pD^0$ relative to $Σ_c(2455)π$

Authors: Belle Collaboration, S. X. Li, C. P. Shen, I. Adachi, J. K. Ahn, H. Aihara, D. M. Asner, H. Atmacan, T. Aushev, R. Ayad, Sw. Banerjee, K. Belous, J. Bennett, M. Bessner, T. Bilka, D. Biswas, D. Bodrov, A. Bozek, M. Bračko, P. Branchini, T. E. Browder, A. Budano, M. Campajola, M. -C. Chang, B. G. Cheon , et al. (103 additional authors not shown)

Abstract: We search for excited charmed baryons in the $Λ_c^+η$ system using a data sample corresponding to an integrated luminosity of 980 $\rm fb^{-1}$. The data were collected by the Belle detector at the KEKB $e^{+}$$e^{-}$ asymmetric-energy collider. No significant signals are found in the $Λ_c^+η$ mass spectrum, including the known $Λ_c(2880)^+$ and $Λ_c(2940)^+$. Clear $Λ_c(2880)^+$ and… ▽ More We search for excited charmed baryons in the $Λ_c^+η$ system using a data sample corresponding to an integrated luminosity of 980 $\rm fb^{-1}$. The data were collected by the Belle detector at the KEKB $e^{+}$$e^{-}$ asymmetric-energy collider. No significant signals are found in the $Λ_c^+η$ mass spectrum, including the known $Λ_c(2880)^+$ and $Λ_c(2940)^+$. Clear $Λ_c(2880)^+$ and $Λ_c(2940)^+$ signals are observed in the $pD^0$ mass spectrum. We set upper limits at 90\% credibility level on ratios of branching fractions of $Λ_c(2880)^+$ and $Λ_c(2940)^+$ decaying to $Λ_c^+η$ relative to $Σ_c(2455)π$ of $<0.13$ for the $Λ_c(2880)^+$ and $<1.11$ for the $Λ_c(2940)^+$. We measure ratios of branching fractions of $Λ_c(2880)^+$ and $Λ_c(2940)^+$ decaying to $pD^0$ relative to $Σ_c(2455)π$ of $0.75 \pm 0.03(\text{stat.}) \pm 0.07(\text{syst.})$ for the $Λ_c(2880)^+$ and $3.59 \pm 0.21(\text{stat.}) \pm 0.56(\text{syst.})$ for the $Λ_c(2940)^+$. △ Less

Submitted 28 July, 2024; v1 submitted 22 June, 2024; originally announced June 2024.

Comments: 10 pages, 4 figures, accepted for publication as a Regular Article in Physical Review D

Report number: Belle Preprint: 2024-06;KEK Preprint: 2024-15

Journal ref: Phys. Rev. D 110, 032021 (2024)

Measurements of the branching fractions of $Ξ_{c}^{0}\toΞ^{0}π^{0}$, $Ξ_{c}^{0}\toΞ^{0}η$, and $Ξ_{c}^{0}\toΞ^{0}η^{\prime}$ and asymmetry parameter of $Ξ_{c}^{0}\toΞ^{0}π^{0}$

Authors: Belle, Belle II Collaborations, :, I. Adachi, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, N. Althubiti, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, R. Ayad, V. Babu, H. Bae, S. Bahinipati, P. Bambade, Sw. Banerjee, M. Barrett, J. Baudot, A. Baur, A. Beaubien , et al. (360 additional authors not shown)

Abstract: We present a study of $Ξ_{c}^{0}\toΞ^{0}π^{0}$, $Ξ_{c}^{0}\toΞ^{0}η$, and $Ξ_{c}^{0}\toΞ^{0}η^{\prime}$ decays using the Belle and Belle~II data samples, which have integrated luminosities of 980~$\mathrm{fb}^{-1}$ and 426~$\mathrm{fb}^{-1}$, respectively. We measure the following relative branching fractions… ▽ More We present a study of $Ξ_{c}^{0}\toΞ^{0}π^{0}$, $Ξ_{c}^{0}\toΞ^{0}η$, and $Ξ_{c}^{0}\toΞ^{0}η^{\prime}$ decays using the Belle and Belle~II data samples, which have integrated luminosities of 980~$\mathrm{fb}^{-1}$ and 426~$\mathrm{fb}^{-1}$, respectively. We measure the following relative branching fractions $${\cal B}(Ξ_{c}^{0}\toΞ^{0}π^{0})/{\cal B}(Ξ_{c}^{0}\toΞ^{-}π^{+}) = 0.48 \pm 0.02 ({\rm stat}) \pm 0.03 ({\rm syst}) ,$$ $${\cal B}(Ξ_{c}^{0}\toΞ^{0}η)/{\cal B}(Ξ_{c}^{0}\toΞ^{-}π^{+}) = 0.11 \pm 0.01 ({\rm stat}) \pm 0.01 ({\rm syst}) ,$$ $${\cal B}(Ξ_{c}^{0}\toΞ^{0}η^{\prime})/{\cal B}(Ξ_{c}^{0}\toΞ^{-}π^{+}) = 0.08 \pm 0.02 ({\rm stat}) \pm 0.01 ({\rm syst}) $$ for the first time, where the uncertainties are statistical ($\rm stat$) and systematic ($\rm syst$). By multiplying by the branching fraction of the normalization mode, ${\mathcal B}(Ξ_{c}^{0}\toΞ^{-}π^{+})$, we obtain the following absolute branching fraction results $(6.9 \pm 0.3 ({\rm stat}) \pm 0.5 ({\rm syst}) \pm 1.3 ({\rm norm})) \times 10^{-3}$, $(1.6 \pm 0.2 ({\rm stat}) \pm 0.2 ({\rm syst}) \pm 0.3 ({\rm norm})) \times 10^{-3}$, and $(1.2 \pm 0.3 ({\rm stat}) \pm 0.1 ({\rm syst}) \pm 0.2 ({\rm norm})) \times 10^{-3}$, for $Ξ_{c}^{0}$ decays to $Ξ^{0}π^{0}$, $Ξ^{0}η$, and $Ξ^{0}η^{\prime}$ final states, respectively. The third errors are from the uncertainty on ${\mathcal B}(Ξ_{c}^{0}\toΞ^{-}π^{+})$. The asymmetry parameter for $Ξ_{c}^{0}\toΞ^{0}π^{0}$ is measured to be $α(Ξ_{c}^{0}\toΞ^{0}π^{0}) = -0.90\pm0.15({\rm stat})\pm0.23({\rm syst})$. △ Less

Submitted 5 October, 2024; v1 submitted 7 June, 2024; originally announced June 2024.

Comments: 23 pages, 5 figures, accepted for publication by JHEP

Report number: Belle II Preprint 2024-015; KEK Preprint 2024-9

Journal ref: JHEP10(2024)045

Measurement of groomed event shape observables in deep-inelastic electron-proton scattering at HERA

Authors: The H1 collaboration, V. Andreev, M. Arratia, A. Baghdasaryan, A. Baty, K. Begzsuren, A. Bolz, V. Boudry, G. Brandt, D. Britzger, A. Buniatyan, L. Bystritskaya, A. J. Campbell, K. B. Cantun Avila, K. Cerny, V. Chekelian, Z. Chen, J. G. Contreras, J. Cvach, J. B. Dainton, K. Daum, A. Deshpande, C. Diaconu, A. Drees, G. Eckerlin , et al. (123 additional authors not shown)

Abstract: The H1 Collaboration at HERA reports the first measurement of groomed event shape observables in deep inelastic electron-proton scattering (DIS) at $\sqrt{s}=319$ GeV, using data recorded between the years 2003 and 2007 with an integrated luminosity of $351$ pb$^{-1}$. Event shapes provide incisive probes of perturbative and non-perturbative QCD. Grooming techniques have been used for jet measurem… ▽ More The H1 Collaboration at HERA reports the first measurement of groomed event shape observables in deep inelastic electron-proton scattering (DIS) at $\sqrt{s}=319$ GeV, using data recorded between the years 2003 and 2007 with an integrated luminosity of $351$ pb$^{-1}$. Event shapes provide incisive probes of perturbative and non-perturbative QCD. Grooming techniques have been used for jet measurements in hadronic collisions; this paper presents the first application of grooming to DIS data. The analysis is carried out in the Breit frame, utilizing the novel Centauro jet clustering algorithm that is designed for DIS event topologies. Events are required to have squared momentum-transfer $Q^2 > 150$ GeV$^2$ and inelasticity $ 0.2 < y < 0.7$. We report measurements of the production cross section of groomed event 1-jettiness and groomed invariant mass for several choices of grooming parameter. Monte Carlo model calculations and analytic calculations based on Soft Collinear Effective Theory are compared to the measurements. △ Less

Submitted 1 August, 2024; v1 submitted 15 March, 2024; originally announced March 2024.

Comments: 32 pages, 17 tables, 7 figures, version as accepted by EPJ C

Report number: DESY-24-036

Journal ref: EPJC 84 (2024), 718

Measurement of the 1-jettiness event shape observable in deep-inelastic electron-proton scattering at HERA

Authors: The H1 collaboration, V. Andreev, M. Arratia, A. Baghdasaryan, A. Baty, K. Begzsuren, A. Bolz, V. Boudry, G. Brandt, D. Britzger, A. Buniatyan, L. Bystritskaya, A. J. Campbell, K. B. Cantun Avila, K. Cerny, V. Chekelian, Z. Chen, J. G. Contreras, J. Cvach, J. B. Dainton, K. Daum, A. Deshpande, C. Diaconu, A. Drees, G. Eckerlin , et al. (124 additional authors not shown)

Abstract: The H1 Collaboration reports the first measurement of the 1-jettiness event shape observable $τ_1^b$ in neutral-current deep-inelastic electron-proton scattering (DIS). The observable $τ_1^b$ is equivalent to a thrust observable defined in the Breit frame. The data sample was collected at the HERA $ep$ collider in the years 2003-2007 with center-of-mass energy of $\sqrt{s}=319\,\text{GeV}$, corres… ▽ More The H1 Collaboration reports the first measurement of the 1-jettiness event shape observable $τ_1^b$ in neutral-current deep-inelastic electron-proton scattering (DIS). The observable $τ_1^b$ is equivalent to a thrust observable defined in the Breit frame. The data sample was collected at the HERA $ep$ collider in the years 2003-2007 with center-of-mass energy of $\sqrt{s}=319\,\text{GeV}$, corresponding to an integrated luminosity of $351.1\,\text{pb}^{-1}$. Triple differential cross sections are provided as a function of $τ_1^b$, event virtuality $Q^2$, and inelasticity $y$, in the kinematic region $Q^2>150\,\text{GeV}^{2}$. Single differential cross section are provided as a function of $τ_1^b$ in a limited kinematic range. Double differential cross sections are measured, in contrast, integrated over $τ_1^b$ and represent the inclusive neutral-current DIS cross section measured as a function of $Q^2$ and $y$. The data are compared to a variety of predictions and include classical and modern Monte Carlo event generators, predictions in fixed-order perturbative QCD where calculations up to $\mathcal{O}(α_s^3)$ are available for $τ_1^b$ or inclusive DIS, and resummed predictions at next-to-leading logarithmic accuracy matched to fixed order predictions at $\mathcal{O}(α_s^2)$. These comparisons reveal sensitivity of the 1-jettiness observable to QCD parton shower and resummation effects, as well as the modeling of hadronization and fragmentation. Within their range of validity, the fixed-order predictions provide a good description of the data. Monte Carlo event generators are predictive over the full measured range and hence their underlying models and parameters can be constrained by comparing to the presented data. △ Less

Submitted 15 March, 2024; originally announced March 2024.

Comments: 45 pages, 38 tables, 13 figures

Report number: DESY-24-035

Observation and differential cross section measurement of neutral current DIS events with an empty hemisphere in the Breit frame

Authors: The H1 collaboration, V. Andreev, M. Arratia, A. Baghdasaryan, A. Baty, K. Begzsuren, A. Bolz, V. Boudry, G. Brandt, D. Britzger, A. Buniatyan, L. Bystritskaya, A. J. Campbell, K. B. Cantun Avila, K. Cerny, V. Chekelian, Z. Chen, J. G. Contreras, J. Cvach, J. B. Dainton, K. Daum, A. Deshpande, C. Diaconu, A. Drees, G. Eckerlin , et al. (124 additional authors not shown)

Abstract: The Breit frame provides a natural frame to analyze lepton-proton scattering events. In this reference frame, the parton model hard interactions between a quark and an exchanged boson defines the coordinate system such that the struck quark is back-scattered along the virtual photon momentum direction. In Quantum Chromodynamics (QCD), higher order perturbative or non-perturbative effects can chang… ▽ More The Breit frame provides a natural frame to analyze lepton-proton scattering events. In this reference frame, the parton model hard interactions between a quark and an exchanged boson defines the coordinate system such that the struck quark is back-scattered along the virtual photon momentum direction. In Quantum Chromodynamics (QCD), higher order perturbative or non-perturbative effects can change this picture drastically. As Bjorken-$x$ decreases below one half, a rather peculiar event signature is predicted with increasing probability, where no radiation is present in one of the two Breit-frame hemispheres and all emissions are to be found in the other hemisphere. At higher orders in $α_s$ or in the presence of soft QCD effects, predictions of the rate of these events are far from trivial, and that motivates measurements with real data. We report on the first observation of the empty current hemisphere events in electron-proton collisions at the HERA collider using data recorded with the H1 detector at a center-of-mass energy of 319 GeV. The fraction of inclusive neutral-current DIS events with an empty hemisphere is found to be $0.0112 \pm 3.9\,\%_\text{stat} \pm 4.5\,\%_\text{syst} \pm 1.6\,\%_\text{mod}$ in the selected kinematic region of $150< Q^2<1500$ GeV$^2$ and inelasticity $0.14< y<0.7$. The data sample corresponds to an integrated luminosity of 351.1 pb$^{-1}$, sufficient to enable differential cross section measurements of these events. The results show an enhanced discriminating power at lower Bjorken-$x$ among different Monte Carlo event generator predictions. △ Less

Submitted 1 August, 2024; v1 submitted 13 March, 2024; originally announced March 2024.

Comments: 13 pages, 5 figures, 2 Tables. This version as accepted for publication

Report number: DESY-24-034

Journal ref: EPJC 84 (2024), 720

Detailed Report on the Measurement of the Positive Muon Anomalous Magnetic Moment to 0.20 ppm

Authors: D. P. Aguillard, T. Albahri, D. Allspach, A. Anisenkov, K. Badgley, S. Baeßler, I. Bailey, L. Bailey, V. A. Baranov, E. Barlas-Yucel, T. Barrett, E. Barzi, F. Bedeschi, M. Berz, M. Bhattacharya, H. P. Binney, P. Bloom, J. Bono, E. Bottalico, T. Bowcock, S. Braun, M. Bressler, G. Cantatore, R. M. Carey, B. C. K. Casey , et al. (168 additional authors not shown)

Abstract: We present details on a new measurement of the muon magnetic anomaly, $a_μ= (g_μ-2)/2$. The result is based on positive muon data taken at Fermilab's Muon Campus during the 2019 and 2020 accelerator runs. The measurement uses $3.1$ GeV$/c$ polarized muons stored in a $7.1$-m-radius storage ring with a $1.45$ T uniform magnetic field. The value of $ a_μ$ is determined from the measured difference b… ▽ More We present details on a new measurement of the muon magnetic anomaly, $a_μ= (g_μ-2)/2$. The result is based on positive muon data taken at Fermilab's Muon Campus during the 2019 and 2020 accelerator runs. The measurement uses $3.1$ GeV$/c$ polarized muons stored in a $7.1$-m-radius storage ring with a $1.45$ T uniform magnetic field. The value of $ a_μ$ is determined from the measured difference between the muon spin precession frequency and its cyclotron frequency. This difference is normalized to the strength of the magnetic field, measured using Nuclear Magnetic Resonance (NMR). The ratio is then corrected for small contributions from beam motion, beam dispersion, and transient magnetic fields. We measure $a_μ= 116 592 057 (25) \times 10^{-11}$ (0.21 ppm). This is the world's most precise measurement of this quantity and represents a factor of $2.2$ improvement over our previous result based on the 2018 dataset. In combination, the two datasets yield $a_μ(\text{FNAL}) = 116 592 055 (24) \times 10^{-11}$ (0.20 ppm). Combining this with the measurements from Brookhaven National Laboratory for both positive and negative muons, the new world average is $a_μ$(exp) $ = 116 592 059 (22) \times 10^{-11}$ (0.19 ppm). △ Less

Submitted 22 May, 2024; v1 submitted 23 February, 2024; originally announced February 2024.

Comments: 48 pages, 29 figures; 4 pages of Supplement Material; version accepted for publication in Physical Review D

Report number: FERMILAB-PUB-24-0084-AD-CSAID-PPD

Progress report on testing robustness of the Newton method in data analysis on 2-point correlation function using a MILC HISQ ensemble

Authors: Tanmoy Bhattacharya, Benjamin J. Choi, Rajan Gupta, Yong-Chull Jang, Seungyeob Jwa, Sunghee Kim, Sunkyu Lee, Weonjong Lee, Jaehoon Leem, Jeonghwan Pak, Sungwoo Park

Abstract: We report recent progress in data analysis on the two point correlation functions which will be prerequisite to obtain semileptonic form factors for the $B_{(s)} \to D_{(s)}\ellν$ decays. We use a MILC HISQ ensemble for the measurement. We use the HISQ action for light quarks, and the Oktay-Kronfeld (OK) action for the heavy quarks ($b$ and $c$). We used a sequential Bayesian method for the data a… ▽ More We report recent progress in data analysis on the two point correlation functions which will be prerequisite to obtain semileptonic form factors for the $B_{(s)} \to D_{(s)}\ellν$ decays. We use a MILC HISQ ensemble for the measurement. We use the HISQ action for light quarks, and the Oktay-Kronfeld (OK) action for the heavy quarks ($b$ and $c$). We used a sequential Bayesian method for the data analysis. Here we test the new fitting methodology of Benjamin J.~Choi in a completely independent manner. △ Less

Submitted 3 January, 2024; originally announced January 2024.

Comments: 9 pages, 7 figures, Lattice 2023 proceedings

Journal ref: PoS(LATTICE2023)155

Current progress on the semileptonic form factors for $\bar{B} \to D^{\ast} \ell \barν$ decay using the Oktay-Kronfeld action

Authors: Tanmoy Bhattacharya, Benjamin J. Choi, Rajan Gupta, Yong-Chull Jang, Seungyeob Jwa, Sunghee Kim, Sunkyu Lee, Weonjong Lee, Jaehoon Leem, Jeonghwan Pak, Sungwoo Park

Abstract: We present recent progress in calculating the semileptonic form factors $h_{A_1}(w)$ for the $\bar{B} \to D^{\ast} \ell \barν$ decays. We use the Oktay-Kronfeld (OK) action for the charm and bottom valence quarks and the HISQ action for light quarks. We adopt the Newton method combined with the scanning method to find a good initial guess for the $χ^2$ minimizer in the fitting of the 2pt correlati… ▽ More We present recent progress in calculating the semileptonic form factors $h_{A_1}(w)$ for the $\bar{B} \to D^{\ast} \ell \barν$ decays. We use the Oktay-Kronfeld (OK) action for the charm and bottom valence quarks and the HISQ action for light quarks. We adopt the Newton method combined with the scanning method to find a good initial guess for the $χ^2$ minimizer in the fitting of the 2pt correlation functions. The main advantage is that the Newton method lets us to consume all the time slices allowed by the physical positivity. We report the first, reliable, but preliminary results for $h_{A_1}(w)/ρ_{A_1}$ at zero recoil ($w=1$). Here we use a MILC HISQ ensemble ($a = 0.12$ fm, $M_π$ = 220 MeV, and $N_f = 2 + 1 + 1$ flavors). △ Less

Submitted 3 January, 2024; originally announced January 2024.

Comments: 9 pages, 3 figures, Lattice 2023 proceeding

Journal ref: PoS(LATTICE2023)245

Stealth dark matter spectrum using LapH and Irreps

Authors: Richard C. Brower, Christopher Culver, Kimmy K. Cushman, George T. Fleming, Anna Hasenfratz, Dean Howarth, James Ingoldby, Xiao Yong Jin, Graham D. Kribs, Aaron S. Meyer, Ethan T. Neil, James C. Osborn, Evan Owen, Sungwoo Park, Claudio Rebbi, Enrico Rinaldi, David Schaich, Pavlos Vranas, Evan Weinberg, Oliver Witzel

Abstract: We present non-perturbative lattice calculations of the low-lying meson and baryon spectrum of the SU(4) gauge theory with fundamental fermion constituents. This theory is one instance of stealth dark matter, a class of strongly coupled theories, where the lowest mass stable baryon is the dark matter candidate. This work constitutes the first milestone in the program to study stealth dark matter s… ▽ More We present non-perturbative lattice calculations of the low-lying meson and baryon spectrum of the SU(4) gauge theory with fundamental fermion constituents. This theory is one instance of stealth dark matter, a class of strongly coupled theories, where the lowest mass stable baryon is the dark matter candidate. This work constitutes the first milestone in the program to study stealth dark matter self-interactions. Here, we focus on reducing excited state contamination in the single baryon channel by applying the Laplacian Heaviside method, as well as projecting our baryon operators onto the irreducible representations of the octahedral group. We compare our resulting spectrum to previous work involving Gaussian smeared non-projected operators and find good agreement with reduced statistical uncertainties. We also present the spectrum of the low-lying odd-parity baryons for the first time. △ Less

Submitted 12 December, 2023; originally announced December 2023.

Comments: 19 pages, 9 figures

Report number: FERMILAB-PUB-23-808-T, RIKEN-iTHEMS-Report-23, IPPP/23/71, LLNL-JRNL-858123

2023 Update of $\varepsilon_K$ with lattice QCD inputs

Authors: Seungyeob Jwa, Jeehun Kim, Sunghee Kim, Sunkyu Lee, Weonjong Lee, Jaehoon Leem, Jeonghwan Pak, Sungwoo Park

Abstract: We report recent progress on $\varepsilon_K$ evaluated directly from the standard model (SM) with lattice QCD inputs such as $\hat{B}_K$, $|V_{cb}|$, $|V_{us}|$, $|V_{ud}|$, $ξ_0$, $ξ_2$, $ξ_\text{LD}$, $f_K$, and $m_c$. We find that the standard model with exclusive $|V_{cb}|$ and lattice QCD inputs describes only 66\% of the experimental value of $|\varepsilon_K|$ and does not explain its remain… ▽ More We report recent progress on $\varepsilon_K$ evaluated directly from the standard model (SM) with lattice QCD inputs such as $\hat{B}_K$, $|V_{cb}|$, $|V_{us}|$, $|V_{ud}|$, $ξ_0$, $ξ_2$, $ξ_\text{LD}$, $f_K$, and $m_c$. We find that the standard model with exclusive $|V_{cb}|$ and lattice QCD inputs describes only 66\% of the experimental value of $|\varepsilon_K|$ and does not explain its remaining 34\%, which corresponds to a strong tension in $|\varepsilon_K|$ at the $4.9σ\sim 3.9σ$ level between the SM theory and experiment. We also find that this tension disappears when we use the inclusive value of $|V_{cb}|$ obtained using the heavy quark expansion based on the QCD sum rule approach. △ Less

Submitted 20 December, 2023; v1 submitted 20 November, 2023; originally announced December 2023.

Comments: 11 pages, 8 tables, 4 figures, Lattice 2023 proceedings. arXiv admin note: substantial text overlap with arXiv:2301.12375, arXiv:2202.11473. references are added

Journal ref: PoS(LATTICE2023)160

Exploring the Synergy of Kinematics and Dynamics for Collider Physics

Authors: Kayoung Ban, Kyoungchul Kong, Myeonghun Park, Seong Chan Park

Abstract: In collider experiments, an event is characterized by two distinct yet mutually complementary features: the `global features' and the `local features'. Kinematic information such as the event topology of a hard process, masses, and spins of particles comprises global features spanning the entire phase space. This global feature can be inferred from reconstructed objects. In contrast, representatio… ▽ More In collider experiments, an event is characterized by two distinct yet mutually complementary features: the `global features' and the `local features'. Kinematic information such as the event topology of a hard process, masses, and spins of particles comprises global features spanning the entire phase space. This global feature can be inferred from reconstructed objects. In contrast, representations of particles in gauge groups, such as Quantum Chromodynamics (QCD), offer localized features revealing the dynamics of an underlying theory. These local features, particularly observed in the patterns of radiation as raw data in various detector components, complement the global kinematic features. In this letter, we propose a simple but effective neural network architecture that seamlessly integrates information from both kinematics and QCD to enhance the signal sensitivity at colliders. △ Less

Submitted 28 November, 2023; originally announced November 2023.

Report number: KIAS-P23059

Measurement of Angular Coefficients of $\bar{B} \to D^* \ell \barν_\ell$: Implications for $|V_{cb}|$ and Tests of Lepton Flavor Universality

Authors: Belle Collaboration, M. T. Prim, F. Bernlochner, F. Metzner, H. Aihara, D. M. Asner, T. Aushev, R. Ayad, V. Babu, Sw. Banerjee, P. Behera, K. Belous, J. Bennett, M. Bessner, V. Bhardwaj, B. Bhuyan, T. Bilka, D. Biswas, D. Bodrov, A. Bondar, J. Borah, M. Bračko, P. Branchini, T. E. Browder, A. Budano , et al. (136 additional authors not shown)

Abstract: We measure the complete set of angular coefficients $J_i$ for exclusive $\bar{B} \to D^* \ell \barν_\ell$ decays ($\ell = e, μ$). Our analysis uses the full $711\,\mathrm{fb}^{-1}$ Belle data set with hadronic tag-side reconstruction. The results allow us to extract the form factors describing the $B \to D^*$ transition and the Cabibbo-Kobayashi-Maskawa matrix element $|V_{\rm cb}|$. Using recent… ▽ More We measure the complete set of angular coefficients $J_i$ for exclusive $\bar{B} \to D^* \ell \barν_\ell$ decays ($\ell = e, μ$). Our analysis uses the full $711\,\mathrm{fb}^{-1}$ Belle data set with hadronic tag-side reconstruction. The results allow us to extract the form factors describing the $B \to D^*$ transition and the Cabibbo-Kobayashi-Maskawa matrix element $|V_{\rm cb}|$. Using recent lattice QCD calculations for the hadronic form factors, we find $|V_{\rm cb}| = (41.0 \pm 0.7) \times 10^3 $ using the BGL parameterization, compatible with determinations from inclusive semileptonic decays. We search for lepton flavor universality violation as a function of the hadronic recoil parameter $w$, and investigate the differences of the electron and muon angular distributions. We find no deviation from Standard Model expectations. △ Less

Submitted 31 October, 2023; originally announced October 2023.

Report number: Belle Preprint 2023-18; KEK Preprint 2023-32

Effective Theory Approach for Axion Wormholes

Authors: Dhong Yeon Cheong, Seong Chan Park, Chang Sub Shin

Abstract: We employ the effective field theory approach to analyze the characteristics of Euclidean wormholes within axion theories. Using this approach, we obtain non-perturbative instantons in various complex scalar models with and without a non-minimal coupling to gravity, as well as models featuring the $R^2$ term for a range of coupling values. This yields a series of analytical expressions for the axi… ▽ More We employ the effective field theory approach to analyze the characteristics of Euclidean wormholes within axion theories. Using this approach, we obtain non-perturbative instantons in various complex scalar models with and without a non-minimal coupling to gravity, as well as models featuring the $R^2$ term for a range of coupling values. This yields a series of analytical expressions for the axion wormhole action, shedding light on the model parameters and field dependencies of contributions in both the ultraviolet and infrared domains. Consequently, model-dependent local operators that disrupt axion shift symmetries are generated at lower energy levels. This, in turn, provides crucial insights into the gravitational influences on the axion quality problem. △ Less

Submitted 19 June, 2024; v1 submitted 17 October, 2023; originally announced October 2023.

Comments: 25 pages, 6 figures, v2: To appear in JHEP, added discussions on the cutoff scale and an appendix on the potential contribution

Report number: CERN-TH-2023-184

Cosmic Birefringence by Dark Photon

Authors: Sung Mook Lee, Dong Woo Kang, Jinn-Ouk Gong, Donghui Jeong, Dong-Won Jung, Seong Chan Park

Abstract: We study the kinetic mixing between the cosmic microwave background (CMB) photon and the birefringent dark photon. These birefringent dark photon may exist in parity-violating dark sector, for example, through the coupling to axion field. We show that the birefringence of the dark photon propagates to the CMB photon, but the resulting birefringence may not be isotropic over the sky, but will be an… ▽ More We study the kinetic mixing between the cosmic microwave background (CMB) photon and the birefringent dark photon. These birefringent dark photon may exist in parity-violating dark sector, for example, through the coupling to axion field. We show that the birefringence of the dark photon propagates to the CMB photon, but the resulting birefringence may not be isotropic over the sky, but will be anisotropic in general. Moreover, our investigation sheds light on the essential role played by kinetic mixing in the generation of two fundamental characteristics of the CMB: circular polarization and spectral distortion. △ Less

Submitted 29 August, 2024; v1 submitted 27 July, 2023; originally announced July 2023.

Comments: 14 pages, 2 figures, 1 table. v2: published version

Report number: CERN-TH-2022-117, KIAS-P22049, APCTP-Pre2022-015

Composite Hybrid Inflation: Dilaton and Waterfall Pions

Authors: Giacomo Cacciapaglia, Dhong Yeon Cheong, Aldo Deandrea, Wanda Isnard, Seong Chan Park

Abstract: We investigate the possibility that inflation originates from a composite field theory, in terms of an effective chiral Lagrangian involving a dilaton and pions. The walking dynamics of the theory constrain the potential in a specific way, where the anomalous dimensions of operators involving pions play a crucial role. For realistic values of the anomalous dimensions, we find a successful hybrid i… ▽ More We investigate the possibility that inflation originates from a composite field theory, in terms of an effective chiral Lagrangian involving a dilaton and pions. The walking dynamics of the theory constrain the potential in a specific way, where the anomalous dimensions of operators involving pions play a crucial role. For realistic values of the anomalous dimensions, we find a successful hybrid inflation occurring via the dilaton-inflaton, with the pions acting as waterfall fields. Compositeness consistency strongly constrain the model, predicting a dilaton scale $f_χ\sim \mathcal{O} (1)$ in unit of the Planck scale, an inflation scale $H_\text{inf} \sim 10^{10}$ GeV, and the pion scale around $10^{14}$ GeV. We further discuss possible phenomenological consequences of this theory. △ Less

Submitted 20 July, 2023; v1 submitted 4 July, 2023; originally announced July 2023.

Comments: 14 pages, 4 figures

Journal ref: JCAP 10 (2023) 063

Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab

Authors: A. Accardi, P. Achenbach, D. Adhikari, A. Afanasev, C. S. Akondi, N. Akopov, M. Albaladejo, H. Albataineh, M. Albrecht, B. Almeida-Zamora, M. Amaryan, D. Androić, W. Armstrong, D. S. Armstrong, M. Arratia, J. Arrington, A. Asaturyan, A. Austregesilo, H. Avagyan, T. Averett, C. Ayerbe Gayoso, A. Bacchetta, A. B. Balantekin, N. Baltzell, L. Barion , et al. (419 additional authors not shown)

Abstract: This document presents the initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV. It is the result of a community effort, incorporating insights from a series of workshops conducted between March 2022 and April 2023. With a track record of over 25 years in delivering the world's most intense and precise multi-GeV electron… ▽ More This document presents the initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV. It is the result of a community effort, incorporating insights from a series of workshops conducted between March 2022 and April 2023. With a track record of over 25 years in delivering the world's most intense and precise multi-GeV electron beams, CEBAF's potential for a higher energy upgrade presents a unique opportunity for an innovative nuclear physics program, which seamlessly integrates a rich historical background with a promising future. The proposed physics program encompass a diverse range of investigations centered around the nonperturbative dynamics inherent in hadron structure and the exploration of strongly interacting systems. It builds upon the exceptional capabilities of CEBAF in high-luminosity operations, the availability of existing or planned Hall equipment, and recent advancements in accelerator technology. The proposed program cover various scientific topics, including Hadron Spectroscopy, Partonic Structure and Spin, Hadronization and Transverse Momentum, Spatial Structure, Mechanical Properties, Form Factors and Emergent Hadron Mass, Hadron-Quark Transition, and Nuclear Dynamics at Extreme Conditions, as well as QCD Confinement and Fundamental Symmetries. Each topic highlights the key measurements achievable at a 22 GeV CEBAF accelerator. Furthermore, this document outlines the significant physics outcomes and unique aspects of these programs that distinguish them from other existing or planned facilities. In summary, this document provides an exciting rationale for the energy upgrade of CEBAF to 22 GeV, outlining the transformative scientific potential that lies within reach, and the remarkable opportunities it offers for advancing our understanding of hadron physics and related fundamental phenomena. △ Less

Submitted 24 August, 2023; v1 submitted 13 June, 2023; originally announced June 2023.

Comments: Updates to the list of authors; Preprint number changed from theory to experiment; Updates to sections 4 and 6, including additional figures

Report number: JLAB-PHY-23-3840

What can a GNOME do? Search targets for the Global Network of Optical Magnetometers for Exotic physics searches

Authors: S. Afach, D. Aybas Tumturk, H. Bekker, B. C. Buchler, D. Budker, K. Cervantes, A. Derevianko, J. Eby, N. L. Figueroa, R. Folman, D. Gavil'an Martin, M. Givon, Z. D. Grujic, H. Guo, P. Hamilton, M. P. Hedges, D. F. Jackson Kimball, S. Khamis, D. Kim, E. Klinger, A. Kryemadhi, X. Liu, G. Lukasiewicz, H. Masia-Roig, M. Padniuk , et al. (28 additional authors not shown)

Abstract: Numerous observations suggest that there exist undiscovered beyond-the-Standard-Model particles and fields. Because of their unknown nature, these exotic particles and fields could interact with Standard Model particles in many different ways and assume a variety of possible configurations. Here we present an overview of the Global Network of Optical Magnetometers for Exotic physics searches (GNOM… ▽ More Numerous observations suggest that there exist undiscovered beyond-the-Standard-Model particles and fields. Because of their unknown nature, these exotic particles and fields could interact with Standard Model particles in many different ways and assume a variety of possible configurations. Here we present an overview of the Global Network of Optical Magnetometers for Exotic physics searches (GNOME), our ongoing experimental program designed to test a wide range of exotic physics scenarios. The GNOME experiment utilizes a worldwide network of shielded atomic magnetometers (and, more recently, comagnetometers) to search for spatially and temporally correlated signals due to torques on atomic spins from exotic fields of astrophysical origin. We survey the temporal characteristics of a variety of possible signals currently under investigation such as those from topological defect dark matter (axion-like particle domain walls), axion-like particle stars, solitons of complex-valued scalar fields (Q-balls), stochastic fluctuations of bosonic dark matter fields, a solar axion-like particle halo, and bursts of ultralight bosonic fields produced by cataclysmic astrophysical events such as binary black hole mergers. △ Less

Submitted 4 May, 2023; v1 submitted 2 May, 2023; originally announced May 2023.

Comments: 22 pages, 12 figures, submitted to Annalen der Physik

Journal ref: Annalen der Physik 2023, 2300083 (2023)

Josephson Parametric Amplifier in Axion Experiments

Authors: Jinmyeong Kim, Boris I. Ivanov, Çağlar Kutlu, Seongtae Park, Arjan F. Van Loo, Yasunobu Nakamura, Sergey V. Uchaikin, Seonjeong Oh, Violeta Gkika, Andrei Matlashov, Woohyun Chung, Yannis K. Semertzidis

Abstract: The axion is a hypothetical particle, a promising candidate for dark matter, and a solution to the strong CP problem. Axion haloscope search experiments deal with a signal power comparable to noise uncertainty at millikelvin temperature. We use a flux-driven Josephson parametric amplifier (JPA) with the aim of approaching a noise level near the theoretically allowed limit of half quanta. In our me… ▽ More The axion is a hypothetical particle, a promising candidate for dark matter, and a solution to the strong CP problem. Axion haloscope search experiments deal with a signal power comparable to noise uncertainty at millikelvin temperature. We use a flux-driven Josephson parametric amplifier (JPA) with the aim of approaching a noise level near the theoretically allowed limit of half quanta. In our measurements to characterize the JPA we have found the added noise to the system with a JPA as the first-stage amplifier to be lower than 110 mK at the frequencies from 0.938 GHz to 0.963 GHz. △ Less

Submitted 19 April, 2023; v1 submitted 10 April, 2023; originally announced April 2023.

Comments: to be published in JPS Conference Proceedings (LT29)

First Simultaneous Determination of Inclusive and Exclusive $\left|V_{ub}\right|$

Authors: Belle Collaboration, L. Cao, F. Bernlochner, K. Tackmann, I. Adachi, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, Sw. Banerjee, P. Behera, K. Belous, J. Bennett, M. Bessner, B. Bhuyan, T. Bilka, D. Biswas, A. Bobrov, D. Bodrov, J. Borah, A. Bozek , et al. (189 additional authors not shown)

Abstract: The first simultaneous determination of the absolute value of the Cabibbo-Kobayashi-Maskawa matrix element $V_{ub}$ using inclusive and exclusive decays is performed with the full Belle data set at the $Υ(4S)$ resonance, corresponding to an integrated luminosity of 711 fb${}^{-1}$. We analyze collision events in which one $B$ meson is fully reconstructed in hadronic modes. This allows for the reco… ▽ More The first simultaneous determination of the absolute value of the Cabibbo-Kobayashi-Maskawa matrix element $V_{ub}$ using inclusive and exclusive decays is performed with the full Belle data set at the $Υ(4S)$ resonance, corresponding to an integrated luminosity of 711 fb${}^{-1}$. We analyze collision events in which one $B$ meson is fully reconstructed in hadronic modes. This allows for the reconstruction of the hadronic $X_u$ system of the semileptonic $b \to u \ell \bar ν_\ell$ decay. We separate exclusive $B \to π\, \ell\, \bar ν_{\ell}$ decays from other inclusive $B \to X_u \, \ell\, \bar ν_{\ell}$ and backgrounds with a two-dimensional fit, that utilizes the number of charged pions in the $X_u$ system and the four-momentum transfer $q^2$ between the $B$ and $X_u$ system. Combining our measurement with information from lattice QCD and QCD calculations of the inclusive partial rate as well as external experimental information on the shape of the $B \to π\, \ell\, \bar ν_{\ell}$ form factor, we determine $\left|V_{ub}^{\mathrm{excl.}} \right| = (3.78 \pm 0.23 \pm 0.16 \pm 0.14)\times 10^{-3}$ and $\left|V_{ub}^{\mathrm{incl.}} \right| = (3.88 \pm 0.20 \pm 0.31 \pm 0.09)\times 10^{-3}$, respectively, with the uncertainties being the statistical error, systematic errors, and theory errors. The ratio of $\left|V_{ub}^{\mathrm{excl.}} \right| / \left|V_{ub}^{\mathrm{incl.}} \right| = 0.97 \pm 0.12$ is compatible with unity. △ Less

Submitted 16 August, 2023; v1 submitted 30 March, 2023; originally announced March 2023.

Comments: 7 pages, 3 captioned figures, including supplemental material

Report number: Belle Preprint 2023-04, KEK Preprint 2022-53

Journal ref: Phys. Rev. Lett. 131, 211801 (2023)

Hot QCD White Paper

Authors: M. Arslandok, S. A. Bass, A. A. Baty, I. Bautista, C. Beattie, F. Becattini, R. Bellwied, Y. Berdnikov, A. Berdnikov, J. Bielcik, J. T. Blair, F. Bock, B. Boimska, H. Bossi, H. Caines, Y. Chen, Y. -T. Chien, M. Chiu, M. E. Connors, M. Csanád, C. L. da Silva, A. P. Dash, G. David, K. Dehmelt, V. Dexheimer , et al. (149 additional authors not shown)

Abstract: Hot QCD physics studies the nuclear strong force under extreme temperature and densities. Experimentally these conditions are achieved via high-energy collisions of heavy ions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). In the past decade, a unique and substantial suite of data was collected at RHIC and the LHC, probing hydrodynamics at the nucleon scale, the… ▽ More Hot QCD physics studies the nuclear strong force under extreme temperature and densities. Experimentally these conditions are achieved via high-energy collisions of heavy ions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). In the past decade, a unique and substantial suite of data was collected at RHIC and the LHC, probing hydrodynamics at the nucleon scale, the temperature dependence of the transport properties of quark-gluon plasma, the phase diagram of nuclear matter, the interaction of quarks and gluons at different scales and much more. This document, as part of the 2023 nuclear science long range planning process, was written to review the progress in hot QCD since the 2015 Long Range Plan for Nuclear Science, as well as highlight the realization of previous recommendations, and present opportunities for the next decade, building on the accomplishments and investments made in theoretical developments and the construction of new detectors. Furthermore, this document provides additional context to support the recommendations voted on at the Joint Hot and Cold QCD Town Hall Meeting, which are reported in a separate document. △ Less

Submitted 30 March, 2023; originally announced March 2023.

Comments: 190 pages, 69 figures

Light quark and antiquark constraints from new electroweak data

Authors: Alberto Accardi, Xiaoxian Jing, Joseph Francis Owens, Sanghwa Park

Abstract: We present a new parton distribution function analysis which includes new data for W boson production in proton-proton collisions and lepton pair production in proton-proton and proton-deuteron collisions. The new data provide strong constraints on the light antiquark parton distribution functions in the proton. We identify an interesting correlation between the $d/u$ ratio and the… ▽ More We present a new parton distribution function analysis which includes new data for W boson production in proton-proton collisions and lepton pair production in proton-proton and proton-deuteron collisions. The new data provide strong constraints on the light antiquark parton distribution functions in the proton. We identify an interesting correlation between the $d/u$ ratio and the $\bar{d}/\bar{u}$ ratio which leads to a modification of our previous results for the $d/u$ ratio as the parton momentum fraction $x \rightarrow 1.$ △ Less

Submitted 20 March, 2023; originally announced March 2023.

Report number: JLAB-THY-23-3782

The Present and Future of QCD

Authors: P. Achenbach, D. Adhikari, A. Afanasev, F. Afzal, C. A. Aidala, A. Al-bataineh, D. K. Almaalol, M. Amaryan, D. Androić, W. R. Armstrong, M. Arratia, J. Arrington, A. Asaturyan, E. C. Aschenauer, H. Atac, H. Avakian, T. Averett, C. Ayerbe Gayoso, X. Bai, K. N. Barish, N. Barnea, G. Basar, M. Battaglieri, A. A. Baty, I. Bautista , et al. (378 additional authors not shown)

Abstract: This White Paper presents the community inputs and scientific conclusions from the Hot and Cold QCD Town Meeting that took place September 23-25, 2022 at MIT, as part of the Nuclear Science Advisory Committee (NSAC) 2023 Long Range Planning process. A total of 424 physicists registered for the meeting. The meeting highlighted progress in Quantum Chromodynamics (QCD) nuclear physics since the 2015… ▽ More This White Paper presents the community inputs and scientific conclusions from the Hot and Cold QCD Town Meeting that took place September 23-25, 2022 at MIT, as part of the Nuclear Science Advisory Committee (NSAC) 2023 Long Range Planning process. A total of 424 physicists registered for the meeting. The meeting highlighted progress in Quantum Chromodynamics (QCD) nuclear physics since the 2015 LRP (LRP15) and identified key questions and plausible paths to obtaining answers to those questions, defining priorities for our research over the coming decade. In defining the priority of outstanding physics opportunities for the future, both prospects for the short (~ 5 years) and longer term (5-10 years and beyond) are identified together with the facilities, personnel and other resources needed to maximize the discovery potential and maintain United States leadership in QCD physics worldwide. This White Paper is organized as follows: In the Executive Summary, we detail the Recommendations and Initiatives that were presented and discussed at the Town Meeting, and their supporting rationales. Section 2 highlights major progress and accomplishments of the past seven years. It is followed, in Section 3, by an overview of the physics opportunities for the immediate future, and in relation with the next QCD frontier: the EIC. Section 4 provides an overview of the physics motivations and goals associated with the EIC. Section 5 is devoted to the workforce development and support of diversity, equity and inclusion. This is followed by a dedicated section on computing in Section 6. Section 7 describes the national need for nuclear data science and the relevance to QCD research. △ Less

Submitted 4 March, 2023; originally announced March 2023.

Comments: QCD Town Meeting White Paper, as submitted to 2023 NSAC LRP committee on Feb. 28, 2023

Journal ref: Nucl.Phys.A 1047 (2024) 122874

The RHIC Cold QCD Program

Authors: Elke-Caroline Aschenauer, Kenneth Barish, Alexander Bazilevsky, Xiaoxuan Chu, James Drachenberg, Oleg Eyser, Renee Fatemi, Carl Gagliardi, Sanghwa Park, Vincent Schoefer, Ralf Seidl, Scott Wissink, Qinghua Xu, Maria Zurek

Abstract: The RHIC Cold QCD program has produced a remarkable breadth of physics results and experimental techniques in the exploration of the fundamental structure of strongly interacting matter over the years. In this document, we present highlights of longitudinal and transverse spin physics to date and the 25 years of innovation in accelerator science from the RHIC Spin program. These measurements and t… ▽ More The RHIC Cold QCD program has produced a remarkable breadth of physics results and experimental techniques in the exploration of the fundamental structure of strongly interacting matter over the years. In this document, we present highlights of longitudinal and transverse spin physics to date and the 25 years of innovation in accelerator science from the RHIC Spin program. These measurements and techniques will be essential to fully realize the scientific missions of the Electron-Ion Collider (EIC) by providing a comprehensive set of measurements in hadronic collisions and laying the foundation for the design of the future EIC. △ Less

Submitted 1 February, 2023; originally announced February 2023.

Comments: 41 pages, 28 figures

2022 Update on $\varepsilon_K$ with lattice QCD inputs

Authors: Sunghee Kim, Sunkyu Lee, Weonjong Lee, Jaehoon Leem, Sungwoo Park

Abstract: We present recent updates for $\varepsilon_K$ determined directly from the standard model (SM) with lattice QCD inputs such as $\hat{B}_K$, $|V_{cb}|$, $|V_{us}|$, $ξ_0$, $ξ_2$, $ξ_\text{LD}$, $f_K$, and $m_c$. We find that the standard model with exclusive $|V_{cb}|$ and other lattice QCD inputs describes only 65% of the experimental value of $|\varepsilon_K|$ and does not explain its remaining 3… ▽ More We present recent updates for $\varepsilon_K$ determined directly from the standard model (SM) with lattice QCD inputs such as $\hat{B}_K$, $|V_{cb}|$, $|V_{us}|$, $ξ_0$, $ξ_2$, $ξ_\text{LD}$, $f_K$, and $m_c$. We find that the standard model with exclusive $|V_{cb}|$ and other lattice QCD inputs describes only 65% of the experimental value of $|\varepsilon_K|$ and does not explain its remaining 35%, which leads to a strong tension in $|\varepsilon_K|$ at the $5.1σ\sim 3.9σ$ level between the SM theory and experiment. We also find that this tension disappears when we use the inclusive value of $|V_{cb}|$ obtained using the heavy quark expansion based on the QCD sum rule approach, although this inclusive tension is small ($\approx 1.4σ$) but keeps increasing as time goes on. △ Less

Submitted 3 February, 2023; v1 submitted 29 January, 2023; originally announced January 2023.

Comments: 10 pages, 6 figures, 8 tables, Lattice 2022 proceeding. arXiv admin note: substantial text overlap with arXiv:2202.11473, arXiv:1912.03024, acknowledgement updated

Journal ref: PoS(LATTICE2022)297

Nucleon form factors and the pion-nucleon sigma term

Authors: Rajan Gupta, Tanmoy Bhattacharya, Vincenzo Cirigliano, Martin Hoferichter, Yong-Chull Jang, Balint Joo, Emanuele Mereghetti, Santanu Mondal, Sungwoo Park, Frank Winter, Boram Yoon

Abstract: This talk summarizes the progress made since Lattice 2021 in understanding and controlling the contributions of towers of multihadron excited states with mass gaps starting lower than of radial excitations, and in increasing our confidence in the extraction of ground state nucleon matrix elements. The most clear evidence for multihadron excited state contributions (ESC) is in axial/pseudoscalar fo… ▽ More This talk summarizes the progress made since Lattice 2021 in understanding and controlling the contributions of towers of multihadron excited states with mass gaps starting lower than of radial excitations, and in increasing our confidence in the extraction of ground state nucleon matrix elements. The most clear evidence for multihadron excited state contributions (ESC) is in axial/pseudoscalar form factors that are required to satisfy the PCAC relation between them. The talk examines the broader question--which and how many of the theoretically allowed positive parity states $N(\textbf p)π(-\textbf p)$, $N(\textbf 0)π(\textbf 0)π(\textbf 0)$, $N(\textbf p)π(\textbf 0)$, $N(\textbf 0)π(\textbf p),\ \ldots$ make significant contributions to a given nucleon matrix element? New data for the axial, electric and magnetic form factors are presented. They continue to show trends observed in Ref[1]. The N${}^2$LO $χ$PT analysis of the ESC to the pion-nucleon sigma term, $σ_{πN}$, has been extended to include the $Δ$ as an explicit degree of freedom [2]. The conclusion reached in Ref [3] that $N π$ and $N ππ$ states each contribute about 10 MeV to $σ_{πN}$, and the consistency between the lattice result with $N π$ state included and the phenomenological estimate is not changed by this improvement. △ Less

Submitted 19 January, 2023; originally announced January 2023.

Comments: 10 pages, 5 figures. Talk presented at the 39th International Symposium on Lattice Field Theory (LATTICE2022) 8-3 August, 2022 Bonn, Germany. arXiv admin note: text overlap with arXiv:2203.05647

Report number: LA-UR-22-33201