Showing 1–50 of 110 results for author: Singh, M

Constraints on ultralight bosons from merging binary and remnant black holes observed during the second and third parts of the fourth LIGO-Virgo-KAGRA observing run

Authors: The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration, A. G. Abac, A. Abe, I. Abouelfettouh, F. Acernese, K. Ackley, A. Adam, S. Adhicary, D. Adhikari, R. X. Adhikari, V. K. Adkins, S. Afroz, A. Agapito, D. Agarwal, M. Agathos, N. Aggarwal, S. Aggarwal, O. D. Aguiar, I. -L. Ahrend, L. Aiello, A. Ain, P. Ajith, T. Akutsu , et al. (1786 additional authors not shown)

Abstract: We present constraints on ultralight bosons using binary black hole mergers observed in the second and third parts of the fourth LIGO-Virgo-KAGRA observing run. Directed searches are conducted for long-transient gravitational waves from ultralight vector boson clouds around merger remnants, using a hidden-Markov-model (HMM) tracking scheme. We target the remnant black holes formed in the binary co… ▽ More We present constraints on ultralight bosons using binary black hole mergers observed in the second and third parts of the fourth LIGO-Virgo-KAGRA observing run. Directed searches are conducted for long-transient gravitational waves from ultralight vector boson clouds around merger remnants, using a hidden-Markov-model (HMM) tracking scheme. We target the remnant black holes formed in the binary coalescences that produced GW250114 and GW250207. We find no evidence for such signals from either target. Estimating our search sensitivity at a threshold corresponding to a 1% false alarm probability, we thus disfavor vector boson masses in the range of $[2.80, 3.95]\times 10^{-13}$ eV with greater than 90% confidence. In addition, we derive constraints on ultralight scalar and vector bosons from the inferred high spins of the constituent black holes in three binaries, using events GW240515, GW241113, and GW241225_08. The excluded mass ranges in this approach depend on the assumed black-hole ages. At $10^5$ years, corresponding to typical dynamically formed binaries, we exclude scalar and vector bosons in the ranges $[1.39, 6.94]\times 10^{-13}$ eV and $[0.32, 14.4]\times 10^{-13}$ eV at 90% confidence, respectively. △ Less

Submitted 11 August, 2026; originally announced August 2026.

Comments: 27 pages (12 pages author list, 15 pages main paper), 5 figures

Report number: LIGO-P2600218

Scaling of the Surface Free Energy as a Probe of the QCD Critical Region

Authors: Joseph I. Kapusta, Mayank Singh, Shensong Wan

Abstract: The QCD phase diagram is expected to have a critical point that separates the crossover and first-order transition lines. A realistic model that incorporates phase boundary effects is essential for heavy ion simulations to isolate the experimental signatures of a critical point. We discuss how to construct such an equation of state, and study its critical behavior. The effect of the coefficient of… ▽ More The QCD phase diagram is expected to have a critical point that separates the crossover and first-order transition lines. A realistic model that incorporates phase boundary effects is essential for heavy ion simulations to isolate the experimental signatures of a critical point. We discuss how to construct such an equation of state, and study its critical behavior. The effect of the coefficient of surface energy on the size of the critical region is investigated. We found that with this construction and with the chosen background equation of state, the temperature must be within one percent of its critical value to observe the critical exponents. This makes it doubtful that the critical exponents can be measured in heavy ion collisions, though it may still be feasible to observe signatures of a first-order phase transition. The method presented here is general and can be utilized with any given equation of state to test the viability of observing critical exponents in experiments. △ Less

Submitted 15 June, 2026; originally announced June 2026.

Comments: 6 pages, 3 figures

Isospin-symmetry violation -- kaons and beyond (ISO-BREAK 25: summary and outlook)

Authors: Marek Gazdzicki, Francesco Giacosa, Katarzyna Grebieszkow, David Blaschke, Marcus Bleicher, Bastian Brandt, Wojciech Brylinski, Tobiasz Czopowicz, Jim Drachenberg, Dipangkar Dutta, Francesca Ercolessi, Mark Gorenstein, Linqin Huang, Oleksii Ivanytskyi, Nicolo Jacazio, Joseph Kapusta, Seweryn Kowalski, Maciej Piotr Lewicki, Manuel Lorenz, Stanislaw Mrowczynski, Vitalii Ozvenchuk, Oleksandra Panova, Roman Planeta, Krzysztof Piasecki, Milena Piotrowska , et al. (18 additional authors not shown)

Abstract: This report summarizes the presentations and discussions during the ISO-BREAK 25 Workshop ``Isospin symmetry violation: kaons and beyond'', which was held at Jan Kochanowski University in Kielce on October 23-25, 2025. We address the current status of the isospin-symmetry breaking discovered by NA61/SHINE in nucleus-nucleus collisions at the CERN SPS, its confirmation by other experiments and stud… ▽ More This report summarizes the presentations and discussions during the ISO-BREAK 25 Workshop ``Isospin symmetry violation: kaons and beyond'', which was held at Jan Kochanowski University in Kielce on October 23-25, 2025. We address the current status of the isospin-symmetry breaking discovered by NA61/SHINE in nucleus-nucleus collisions at the CERN SPS, its confirmation by other experiments and studies in \ee and deep inelastic scattering. In addition, we discuss the theoretical status as well as we outline experimental and theoretical priorities towards understanding this currently unexplained phenomenon. △ Less

Submitted 17 April, 2026; originally announced April 2026.

Comments: 33 pages, 12 figures

Longitudinal Dynamics of Large and Small Systems from a 3D Bayesian Calibration of RHIC Top-energy Collision Data

Authors: A. Mankolli, C. Shen, M. Luzum, J. -F. Paquet, M. Singh, J. Velkovska, S. A. Bass, C. Gale, G. A. C. da Silva, L. Du, L. Kasper, G. S. Rocha, D. Soeder, S. Tuo, G. Vujanovic, X. Wu, W. Zhao, M. Chartier, Y. Chen, R. Datta, R. Dolan, R. Ehlers, H. Elfner, R. J. Fries, D. A. Hangal , et al. (31 additional authors not shown)

Abstract: A comprehensive Bayesian analysis of the 3D dynamics of high-energy nuclear collisions is presented. We perform a systematic model-to-data comparison using simulations of large and small collision systems, and a broad range of measurements from the PHENIX, STAR, PHOBOS, and BRAHMS collaborations spanning nearly two decades of RHIC operations. In particular, we perform fully 3D multi-stage simulati… ▽ More A comprehensive Bayesian analysis of the 3D dynamics of high-energy nuclear collisions is presented. We perform a systematic model-to-data comparison using simulations of large and small collision systems, and a broad range of measurements from the PHENIX, STAR, PHOBOS, and BRAHMS collaborations spanning nearly two decades of RHIC operations. In particular, we perform fully 3D multi-stage simulations including rapidity-dependent energy deposition with global energy conservation using the 3D Glauber model, along with relativistic viscous hydrodynamics with MUSIC. We calibrate the model on rapidity- and $p_T$-differential observables and analyze the respective constraints on initial state and transport properties they provide. We emphasize the additional constraints provided by rapidity-dependent measurements, the differences in large and small system calibrations, and the tension exhibited by particular observables. We use our calibrated model to make predictions of observables in p-Au and $^3$He-Au collisions. Furthermore, we facilitate direct comparison of experimental measurements by highlighting the dependence of flow measurements on the rapidity of the regions of interest and reference, as well as the importance of the centrality selection. In particular, we examine the apparent differences between the STAR and PHENIX $v_2$ and $v_3$ measurements in small systems. △ Less

Submitted 29 July, 2026; v1 submitted 23 January, 2026; originally announced January 2026.

Journal ref: Phys. Rev. C 114, 014905 Vol. 114, Iss. 1, July 2026

Search for Cosmic Ray Electron Boosted Dark Matter with the CDEX-10 Experiment

Authors: R. Xu, L. T. Yang, Q. Yue, K. J. Kang, Y. J. Li, H. P. An, Greeshma C., J. P. Chang, H. Chen, Y. H. Chen, J. P. Cheng, J. Y. Cui, W. H. Dai, Z. Deng, Y. X. Dong, C. H. Fang, H. Gong, Q. J. Guo, T. Guo, X. Y. Guo, L. He, J. R. He, H. X. Huang, T. C. Huang, S. Karmakar , et al. (63 additional authors not shown)

Abstract: We present new constraints on the cosmic ray electron boosted light dark matter (CReDM) using the 205.4 kg$\cdot$day data of the CDEX-10 experiment located at the China Jinping Underground Laboratory. The cosmic ray electron spectrum and distribution in the Galaxy are generated by the $\tt GALPROP$ code package. In the calculation process of DM-electron scattering process in the Galaxy, we conside… ▽ More We present new constraints on the cosmic ray electron boosted light dark matter (CReDM) using the 205.4 kg$\cdot$day data of the CDEX-10 experiment located at the China Jinping Underground Laboratory. The cosmic ray electron spectrum and distribution in the Galaxy are generated by the $\tt GALPROP$ code package. In the calculation process of DM-electron scattering process in the Galaxy, we consider the energy-dependency of the DM-electron scattering cross section. The constraints on CReDM are set for both heavy and light mediator scenarios using the CDEX-10 dataset. The result exceeds previous Standard Halo Model (SHM) limits for DM mass lower than 0.6 MeV in heavy mediator case and corresponds to the best sensitivity among all direct detection experiments from 1 keV to 0.5 MeV in the light mediator scenario. △ Less

Submitted 13 January, 2026; originally announced January 2026.

Comments: 7 pages, 5 figures

Electron-positron pair creation induced by multi-pulse train of electric fields: effect of randomness in time-delay

Authors: Deepak Sah, Manoranjan P. Singh

Abstract: We investigate the creation of electron-positron pairs (EPPs) in a sequence of alternating-sign, time-dependent electric field pulse trains by solving the quantum Vlasov equations. Specifically, we focus on Sauter-like pulse trains with random time delays between successive pulses, drawn from a Gaussian distribution wherein the extent of fluctuations is controlled by the standard deviation $σ_T$ o… ▽ More We investigate the creation of electron-positron pairs (EPPs) in a sequence of alternating-sign, time-dependent electric field pulse trains by solving the quantum Vlasov equations. Specifically, we focus on Sauter-like pulse trains with random time delays between successive pulses, drawn from a Gaussian distribution wherein the extent of fluctuations is controlled by the standard deviation $σ_T$ of the distribution. We find that increasing $σ_T$ leads to a dramatic transformation in the longitudinal momentum spectrum. The well-known fringe pattern, akin to that in the multi-slit interference, gets significantly modified. The averaged spectra exhibit a robust Gaussian-like envelope with residual oscillations, which are much more prominent in the central momentum region. Notably, we find that in certain cases, stochastic time delays lead to a pronounced enhancement in the central peak of the distribution function for pulse train containing $N$ pulses. For example, for $N=20$ pulses, $σ_T \approx 31$ $[m^{-1}]$(about $17\%$ of the mean time delay) yields nearly a tenfold increase in the central peak, which for $σ_T \approx 50$ $[m^{-1}]$ (about $27\%$ of the mean time delay), scales up to $10^3.$ This may open up new possibilities for optimizing multi-pulse field configurations and guide future experimental designs aimed at maximizing EPPs creation. △ Less

Submitted 12 December, 2025; originally announced December 2025.

Constraints on ultraheavy dark matter from the CDEX-10 experiment at the China Jinping Underground Laboratory

Authors: Y. F. Wang, L. T. Yang, Q. Yue, K. J. Kang, Y. J. Li, H. P. An, Greeshma C., J. P. Chang, H. Chen, Y. H. Chen, J. P. Cheng, J. Y. Cui, W. H. Dai, Z. Deng, Y. X. Dong, C. H. Fang, H. Gong, Q. J. Guo, T. Guo, X. Y. Guo, L. He, J. R. He, H. X. Huang, T. C. Huang, S. Karmakar , et al. (63 additional authors not shown)

Abstract: We report a search for ultraheavy dark matter (UHDM) with the CDEX-10 experiment at the China Jinping Underground Laboratory. Using a Monte Carlo framework that incorporates Earth shielding effects, we simulated UHDM propagation and energy deposition in p-type point-contact germanium detectors. Analysis of 205.4 kg$\cdot$day exposure in the 0.16--4.16 keVee range showed no excess above background.… ▽ More We report a search for ultraheavy dark matter (UHDM) with the CDEX-10 experiment at the China Jinping Underground Laboratory. Using a Monte Carlo framework that incorporates Earth shielding effects, we simulated UHDM propagation and energy deposition in p-type point-contact germanium detectors. Analysis of 205.4 kg$\cdot$day exposure in the 0.16--4.16 keVee range showed no excess above background. Our results exclude the spin-independent UHDM-nucleon scattering with two cross section scales, with the UHDM mass from $10^6$ to $10^{11}$ GeV, and provide the most stringent constraints with solid-state detectors below $10^8$ GeV. △ Less

Submitted 28 March, 2026; v1 submitted 24 October, 2025; originally announced October 2025.

Comments: 8 pages, 5 figures. Version updated to match PRD version

Journal ref: Phys. Rev. D 113, 052011 (2026)

Constraints on inelastic dark matter from the CDEX-1B experiment

Authors: Y. F. Liang, L. T. Yang, Q. Yue, K. J. Kang, Y. J. Li, H. P. An, Greeshma C., J. P. Chang, H. Chen, Y. H. Chen, J. P. Cheng, J. Y. Cui, W. H. Dai, Z. Deng, Y. X. Dong, C. H. Fang, H. Gong, Q. J. Guo, T. Guo, X. Y. Guo, L. He, J. R. He, H. X. Huang, T. C. Huang, S. Karmakar , et al. (63 additional authors not shown)

Abstract: We present limits on spin-independent inelastic weakly interacting massive particles (WIMP)-nucleus scattering using the 737.1 kg$\cdot$day dataset from the CDEX-1B experiment. Expected nuclear recoil spectra for various inelastic WIMP masses $m_χ$ and mass splittings $δ$ are calculated under the standard halo model. An accurate background model of CDEX-1B is constructed by simulating all major ba… ▽ More We present limits on spin-independent inelastic weakly interacting massive particles (WIMP)-nucleus scattering using the 737.1 kg$\cdot$day dataset from the CDEX-1B experiment. Expected nuclear recoil spectra for various inelastic WIMP masses $m_χ$ and mass splittings $δ$ are calculated under the standard halo model. An accurate background model of CDEX-1B is constructed by simulating all major background sources. The model parameters are then determined through maximum likelihood estimation and Markov chain Monte Carlo fitting. The resulting 90\% confidence level upper limits on the WIMP-nucleon cross section $σ_{\mathrm{n}}$ exclude certain DAMA/LIBRA allowed regions: the $χ^2 < 4$ regions for $δ< 30$ keV at $m_χ= 250$ GeV and the $χ^2 < 9$ region for $δ< 50$ keV at $m_χ= 500$ GeV. The method is applicable to other inelastic dark matter scenarios, and the upcoming CDEX-50 experiment is expected to improve sensitivity by four orders of magnitude. △ Less

Submitted 31 December, 2025; v1 submitted 9 October, 2025; originally announced October 2025.

Comments: 10 pages, 8 figures. Version updated to match PRD version

Journal ref: Phys. Rev. D 112, 112025 (2025)

Transport-based initial conditions for heavy-ion collisions at finite densities

Authors: H. Roch, G. Pihan, A. Monnai, S. Ryu, N. Senthilkumar, J. Staudenmaier, H. Elfner, B. Schenke, J. H. Putschke, C. Shen, S. A. Bass, M. Chartier, Y. Chen, R. Datta, R. Dolan, L. Du, R. Ehlers, R. J. Fries, C. Gale, D. A. Hangal, B. V. Jacak, P. M. Jacobs, S. Jeon, Y. Ji, F. Jonas , et al. (31 additional authors not shown)

Abstract: We employ the SMASH transport model to provide event-by-event initial conditions for the energy-momentum tensor and conserved charge currents in hydrodynamic simulations of relativistic heavy-ion collisions. We study the fluctuations and dynamical evolution of three conserved charge currents (net baryon, net electric charges, and net strangeness) with a 4D lattice-QCD-based equation of state, NEOS… ▽ More We employ the SMASH transport model to provide event-by-event initial conditions for the energy-momentum tensor and conserved charge currents in hydrodynamic simulations of relativistic heavy-ion collisions. We study the fluctuations and dynamical evolution of three conserved charge currents (net baryon, net electric charges, and net strangeness) with a 4D lattice-QCD-based equation of state, NEOS-4D, in the hydrodynamic phase. Out-of-equilibrium corrections at the particlization are generalized to finite densities to ensure the conservation of energy, momentum, and the three types of charges. These theoretical developments are integrated within the X-SCAPE code as a unified framework for studying the nuclear matter properties in the Beam Energy Scan program. △ Less

Submitted 16 February, 2026; v1 submitted 8 October, 2025; originally announced October 2025.

Comments: 17 pages, 12 figures

Journal ref: Phys. Rev. C 113 (2026) 2, 024907

Relativistic hydrodynamics with spinodal decomposition

Authors: Joseph Kapusta, Mayank Singh, Thomas Welle

Abstract: We introduce the equations of relativistic hydrodynamics that incorporate phase separation via spinodal decomposition. These equations consider surface effects between the two phases and are applicable for simulating intermediate-energy heavy-ion collisions and binary neutron star mergers, where a first-order phase transition is expected. We solve these equations in the context of Bjorken flow, wh… ▽ More We introduce the equations of relativistic hydrodynamics that incorporate phase separation via spinodal decomposition. These equations consider surface effects between the two phases and are applicable for simulating intermediate-energy heavy-ion collisions and binary neutron star mergers, where a first-order phase transition is expected. We solve these equations in the context of Bjorken flow, which offers the relevant geometric framework for ion collisions. △ Less

Submitted 30 September, 2025; originally announced October 2025.

Comments: 4 pages, 3 figures. Proceedings for Quark Matter 2025

Pre-equilibrium charm quark dynamics and their impact on D-Meson observables

Authors: Manu Kurian, Mayank Singh, Charles Gale, Sangyong Jeon, Björn Schenke

Abstract: We study the impact of pre-equilibrium evolution on the charm quark $R_{AA}$ and $v_2$ in Pb+Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV. We observe that there is significant diffusion in the pre-equilibrium evolution, but there is no measurable effect on the final state observables. We study the impact of pre-equilibrium evolution on the charm quark $R_{AA}$ and $v_2$ in Pb+Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV. We observe that there is significant diffusion in the pre-equilibrium evolution, but there is no measurable effect on the final state observables. △ Less

Submitted 30 September, 2025; originally announced September 2025.

Comments: 4 pages, 3 figures, proceedings for Quark Matter 2025 conference

Charm quark evolution in the early stages of heavy-ion collisions

Authors: Mayank Singh, Manu Kurian, Björn Schenke, Sangyong Jeon, Charles Gale

Abstract: Heavy quarks are predominantly generated at the initial stage of relativistic heavy-ion collisions such that heavy flavor observables have the potential to provide information on the pre-equilibrium medium dynamics. In this study, we investigate the sensitivity of D-meson $R_{AA}$ and $v_2$ to early-time charm quark dynamics in Pb+Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV. We employ the IP-Glasma+… ▽ More Heavy quarks are predominantly generated at the initial stage of relativistic heavy-ion collisions such that heavy flavor observables have the potential to provide information on the pre-equilibrium medium dynamics. In this study, we investigate the sensitivity of D-meson $R_{AA}$ and $v_2$ to early-time charm quark dynamics in Pb+Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV. We employ the IP-Glasma+MUSIC+UrQMD framework to model the evolution of the bulk medium. Charm quarks are generated using PYTHIA with nuclear parton distribution functions and evolved using Langevin dynamics within MARTINI. We observe that even though there is significant momentum broadening in the earliest stage, D-meson $R_{AA}$ and $v_2$ are only weakly sensitive to pre-equilibrium interactions. △ Less

Submitted 12 February, 2026; v1 submitted 23 September, 2025; originally announced September 2025.

Comments: Matches published version; 12 pages, 9 figures,

Journal ref: Phys. Rev. C 113, 024904 (2026)

Exploring the Fundamental Properties of Neutrino from Oscillation Experiments

Authors: Masoom Singh

Abstract: As physicists pursue precision neutrino measurements, complementary experiments covering varied oscillation landscapes have become essential for resolving current tensions in global fits. This thesis presents projected sensitivities and forecasted performance of two next-generation long-baseline experiments: DUNE and T2HK, through detailed simulations addressing fundamental questions including neu… ▽ More As physicists pursue precision neutrino measurements, complementary experiments covering varied oscillation landscapes have become essential for resolving current tensions in global fits. This thesis presents projected sensitivities and forecasted performance of two next-generation long-baseline experiments: DUNE and T2HK, through detailed simulations addressing fundamental questions including neutrino mass ordering, leptonic CP violation, and the octant of $θ_{23}$. We demonstrate through simulated analyses that while each experiment alone faces inherent degeneracies, their complementary features enable breakthrough projected sensitivities in both standard oscillation parameter measurements and forecasted searches for new physics beyond the Standard Model. The combined simulation results reveal that DUNE-T2HK synergy will be crucial for achieving a comprehensive understanding of neutrino properties in the coming decade. △ Less

Submitted 23 September, 2025; originally announced September 2025.

Comments: Ph.D. Thesis(Supervisor: Swapna Mahapatra, Co-supervisor: Sanjib Kumar Agarwalla), 214 pages, 49 figures, 20 tables. http://hdl.handle.net/10603/609776

Neutrino mass and mixing, resonant leptogenesis and charged lepton flavor violation in a minimal inverse seesaw model with $S_4$ symmetry

Authors: V. V. Vien, Mayengbam Kishan Singh

Abstract: We propose a minimal inverse seesaw model with $S_4$ symmetry for the Majorana neutrinos with only one real ($m_0$)-and two complex ($α, β$) parameters in neutrino sector which gives reasonable predictions for the neutrino oscillation parameters, the observed baryon asymmetry of the Universe and the charged lepton flavor violation. The resulting model reveals a favor for normal neutrino mass order… ▽ More We propose a minimal inverse seesaw model with $S_4$ symmetry for the Majorana neutrinos with only one real ($m_0$)-and two complex ($α, β$) parameters in neutrino sector which gives reasonable predictions for the neutrino oscillation parameters, the observed baryon asymmetry of the Universe and the charged lepton flavor violation. The resulting model reveals a favor for normal neutrino mass ordering, a higher octant of $θ_{23}$ and a lower half-plane of Dirac CP violation phase. The predictions of the model for sum of neutrino masses and the effective Majorana neutrino mass are centered around 58.98 meV and 6.2 meV, respectively. The model also provides the predictions of the baryon asymmetry and charged lepton flavour violation processes which are consistent with the experimental observations. △ Less

Submitted 3 June, 2026; v1 submitted 10 September, 2025; originally announced September 2025.

Comments: 19 pages, 8 figures, 4 tables

Journal ref: Eur. Phys. J. C 86, 453 (2026)

Acausality-driven instabilities in transient relativistic viscous hydrodynamics

Authors: Lorenzo Gavassino, Henry Hirvonen, Jean-François Paquet, Mayank Singh, Gabriel Soares Rocha

Abstract: We investigate non-linear instabilities stemming from superluminal propagation of information in Israel-Stewart-like models of relativistic viscous fluid dynamics. In relativity, the characteristic speed of propagation of information, $w$, and the speed of the fluid, $v$, allow us to differentiate between regimes of the hydrodynamic equations that are acausal but stable ($w>1$), unstable (… ▽ More We investigate non-linear instabilities stemming from superluminal propagation of information in Israel-Stewart-like models of relativistic viscous fluid dynamics. In relativity, the characteristic speed of propagation of information, $w$, and the speed of the fluid, $v$, allow us to differentiate between regimes of the hydrodynamic equations that are acausal but stable ($w>1$), unstable ($v^{2} w^{2} \geq 1$), and covariantly ill-posed ($w^{2} \leq 0$). As an analytical benchmark, we present a new solution that illustrates these distinct regimes. We compare this analytical solution to the result of a numerical relativistic viscous fluid dynamics solver, and confirm that the analytical result can be recovered numerically in the stable regime, whether causal or acausal. The onset of numerical instabilities is further found to occur in the regime predicted by the analytical solution. △ Less

Submitted 16 October, 2025; v1 submitted 6 August, 2025; originally announced August 2025.

Comments: 16 pages, 6 figures -- v2 after peer-review version

Interplay of prompt and non-prompt photons in photon-triggered jet observables

Authors: Chathuranga Sirimanna, Yasuki Tachibana, Abhijit Majumder, Aaron Angerami, Ritu Arora, Steffen Bass, Yi Chen, Ritoban Datta, Lipei Du, Raymond Ehlers, Hannah Elfner, Rainer J. Fries, Charles Gale, Yayun He, Barbara Jacak, Peter Jacobs, Sangyong Jeon, Yi Ji, Florian Jonas, Lauren Kasper, Michael Kordell, Amit Kumar, Raghav Kunnawalkam-Elayavalli, Joseph Latessa, Yen-Jie Lee , et al. (27 additional authors not shown)

Abstract: Prompt photons are important yet challenging to observe in relativistic heavy-ion collisions, as they are produced in the early stages and traverse almost the entire QGP medium without interaction. Experimental analyses typically employ isolation cuts, in the hope to identify prompt photons. Most theoretical studies consider only events with actual prompt photons, assuming no contribution from iso… ▽ More Prompt photons are important yet challenging to observe in relativistic heavy-ion collisions, as they are produced in the early stages and traverse almost the entire QGP medium without interaction. Experimental analyses typically employ isolation cuts, in the hope to identify prompt photons. Most theoretical studies consider only events with actual prompt photons, assuming no contribution from isolated non-prompt photons to reduce computational cost. For the first time, we present a study that compares simulation results generated using inclusive (bremsstrahlung) and prompt-photon events with multiple experimental observables for both $p-p$ and $Pb-Pb$ collisions at $5.02$ TeV. Simulations are carried out using the multi-stage JETSCAPE framework tuned to describe the quenching of jets and hadrons. Isolated non-prompt photons are generated in hard photon bremsstrahlung, where the photon is radiated at a sufficient angle to the jet. Several photon triggered jet and jet substructure observables show significant contributions from inclusive photons, yielding an improvement in comparison with experimental data. Novel photon triggered jet substructure observables are also expected to show new structures, yet to be detected in experiment. This effort examines the significance of isolated non-prompt photons using parameters tuned for a simultaneous description of the leading hadron and jet spectrum, and thus provides an independent verification of the multistage evolution framework. △ Less

Submitted 1 July, 2025; originally announced July 2025.

Comments: 5 pages, 4 figures

Effects of hadronic reinteraction on jet fragmentation from small to large systems

Authors: Hendrik Roch, Aaron Angerami, Ritu Arora, Steffen Bass, Yi Chen, Ritoban Datta, Lipei Du, Raymond Ehlers, Hannah Elfner, Rainer J. Fries, Charles Gale, Yayun He, Barbara Jacak, Peter Jacobs, Sangyong Jeon, Yi Ji, Florian Jonas, Lauren Kasper, Michael Kordell II, Amit Kumar, Raghav Kunnawalkam-Elayavalli, Joseph Latessa, Yen-Jie Lee, Roy Lemmon, Matt Luzum , et al. (27 additional authors not shown)

Abstract: We investigate the impact of the hadronic phase on jet quenching in nuclear collider experiments, an open question in heavy-ion physics. Previous studies in a simplified setup suggest that hadronic interactions could have significant effects, but a systematic analysis is needed. Using the X-SCAPE event generator with the SMASH afterburner, we study the role of hadronic rescattering on jet fragment… ▽ More We investigate the impact of the hadronic phase on jet quenching in nuclear collider experiments, an open question in heavy-ion physics. Previous studies in a simplified setup suggest that hadronic interactions could have significant effects, but a systematic analysis is needed. Using the X-SCAPE event generator with the SMASH afterburner, we study the role of hadronic rescattering on jet fragmentation hadrons. Applying this framework to $e^++e^-$ collisions, we demonstrate that even in small systems with limited particle production, hadronic interactions lead to measurable modifications in final-state hadronic and jet observables by comparing scenarios with and without afterburner rescattering. △ Less

Submitted 19 June, 2025; originally announced June 2025.

Comments: 6 pages, 3 figures, conference proceedings for Hard Probes 2024

Journal ref: EPJ Web Conf. 339 (2025) 02017

Extraction of jet-medium interaction details through jet substructure for inclusive and gamma-tagged jets

Authors: Y. Tachibana, C. Sirimanna, A. Majumder, A. Angerami, R. Arora, S. A. Bass, Y. Chen, R. Datta, L. Du, R. Ehlers, H. Elfner, R. J. Fries, C. Gale, Y. He, B. V. Jacak, P. M. Jacobs, S. Jeon, Y. Ji, F. Jonas, L. Kasper, M. Kordell II, A. Kumar, R. Kunnawalkam-Elayavalli, J. Latessa, Y. -J. Lee , et al. (27 additional authors not shown)

Abstract: We present a comprehensive study of jet substructure modifications in high-energy heavy-ion collisions using both inclusive jets and $γ$-tagged jets, based on a multi-stage jet evolution model within the Monte Carlo framework JETSCAPE. To investigate hard parton splittings inside jets, we focus on Soft Drop observables. Our results for the groomed splitting radius and groomed jet mass distribution… ▽ More We present a comprehensive study of jet substructure modifications in high-energy heavy-ion collisions using both inclusive jets and $γ$-tagged jets, based on a multi-stage jet evolution model within the Monte Carlo framework JETSCAPE. To investigate hard parton splittings inside jets, we focus on Soft Drop observables. Our results for the groomed splitting radius and groomed jet mass distributions of inclusive jets show a slight narrowing compared to proton-proton baselines. We demonstrate that this apparent narrowing is primarily a selection bias from energy loss, rather than a direct modification of the splitting structure, by analyzing $γ$-tagged jets, where such bias is eliminated or significantly reduced. We also show that quark jets exhibit genuine modifications in their splitting structure, which is not seen in gluon jets. These effects are clearly visible in the substructure of $γ$-tagged jets, which are dominated by quark jets, but are not apparent for inclusive jets. This demonstrates that $γ$-tagged jets offer a powerful probe of medium-induced modifications to the hard splitting structure of jets. △ Less

Submitted 18 June, 2025; originally announced June 2025.

Comments: 5 pages, 3 figures, Proceedings of the 12th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2024), September 22-27, 2024, Nagasaki, Japan

Constraints on dark matter boosted by supernova shock within the effective field theory framework from the CDEX-10 experiment

Authors: J. Z. Wang, L. T. Yang, Q. Yue, K. J. Kang, Y. J. Li, H. P. An, Greeshma C., J. P. Chang, H. Chen, Y. H. Chen, J. P. Cheng, W. H. Dai, Z. Deng, C. H. Fang, X. P. Geng, H. Gong, Q. J. Guo, T. Guo, X. Y. Guo, L. He, J. R. He, H. X. Huang, T. C. Huang, S. Karmakar, H. B. Li , et al. (62 additional authors not shown)

Abstract: Supernova shocks can boost dark matter (DM) particles to high, yet nonrelativistic, velocities, providing a suitable mechanism for analysis within the framework of the nonrelativistic effective field theory (NREFT). These accelerated DM sources extend the experimental ability to scan the parameter space of light DM into the sub-GeV region. In this study, we specifically analyze DM accelerated by t… ▽ More Supernova shocks can boost dark matter (DM) particles to high, yet nonrelativistic, velocities, providing a suitable mechanism for analysis within the framework of the nonrelativistic effective field theory (NREFT). These accelerated DM sources extend the experimental ability to scan the parameter space of light DM into the sub-GeV region. In this study, we specifically analyze DM accelerated by the Monogem Ring supernova remnant, whose age ($\sim 68000$ yr) and distance to Earth ($\sim 300$ parsec) are strategically matched to enable detection with current terrestrial detectors. Utilizing the 205.4 kg$\cdot$day data obtained from the CDEX-10 experiment at the China Jinping Underground Laboratory, we derive new constraints on boosted DM within the NREFT framework. The NREFT coupling constant exclusion regions now penetrate the sub-GeV mass range, with optimal sensitivity achieved for operators $\mathcal{O}_{3}$, $\mathcal{O}_{6}$, $\mathcal{O}_{15}$ in the 0.4--0.6 GeV mass range. △ Less

Submitted 18 November, 2025; v1 submitted 4 April, 2025; originally announced April 2025.

Comments: 9 pages, 5 figures. Version updated to match PRD version

Journal ref: Phys. Rev. D 112, 092011 (2025)

The effect of recoils on soft-drop-groomed observables in $γ$-tagged jets in a multistage approach

Authors: Y. Tachibana, C. Sirimanna, A. Majumder, A. Angerami, R. Arora, S. A. Bass, Y. Chen, R. Datta, L. Du, R. Ehlers, H. Elfner, R. J. Fries, C. Gale, Y. He, B. V. Jacak, P. M. Jacobs, S. Jeon, Y. Ji, F. Jonas, L. Kasper, M. Kordell II, A. Kumar, R. Kunnawalkam-Elayavalli, J. Latessa, Y. -J. Lee , et al. (27 additional authors not shown)

Abstract: We investigate medium-induced modifications to jet substructure observables that characterize hard components in central Pb-Pb collisions at $\sqrt{s_{NN}}=5.02$~TeV. Using a multistage Monte Carlo simulation of in-medium jet shower evolution, we explore flavor-dependent medium effects through simulations of inclusive and $γ$-tagged jets. The results show that quark jets undergo a nonmonotonic mod… ▽ More We investigate medium-induced modifications to jet substructure observables that characterize hard components in central Pb-Pb collisions at $\sqrt{s_{NN}}=5.02$~TeV. Using a multistage Monte Carlo simulation of in-medium jet shower evolution, we explore flavor-dependent medium effects through simulations of inclusive and $γ$-tagged jets. The results show that quark jets undergo a nonmonotonic modification compared with gluon jets in observables such as the Pb-Pb to $p$-$p$ ratio of the soft drop prong angle $r_g$, the relative prong transverse momentum $k_{T,g}$, and the groomed mass $m_g$ distributions. Due to this nonmonotonic modification, $γ$-tagged jets, enriched in quark jets, provide surprisingly clear signals of medium-induced structural modifications, distinct from effects dominated by selection bias. Further systematic studies demonstrate that these effects are dominated by recoil medium response. This work highlights the potential of hard substructures in $γ$-tagged jets as powerful tools for probing the jet-medium interactions in high-energy heavy-ion collisions, in particular by enabling detailed investigations of jet-medium parton scatterings via their associated medium response. All simulations for $γ$-tagged jet analyses carried out in this paper used triggered events containing at least one hard photon, which highlights the utility of these observables for future Bayesian analysis. △ Less

Submitted 13 March, 2026; v1 submitted 30 March, 2025; originally announced March 2025.

Comments: 31 pages, 35 figures

Journal ref: Phys. Rev. C 113, 034910 (2026)

Vacuum polarization current in presence of intense Sauter field

Authors: Deepak Sah, Manoranjan P. Singh

Abstract: The quantum vacuum becomes unstable under an external field, leading to spontaneous particle-antiparticle pair creation. In canonical quantization, the time-dependent particle number, defined via Bogoliubov transformations lacks physical meaning until the external field vanishes. To address this, we explore dynamical quantities that remain well-defined at both asymptotic and intermediate times, fo… ▽ More The quantum vacuum becomes unstable under an external field, leading to spontaneous particle-antiparticle pair creation. In canonical quantization, the time-dependent particle number, defined via Bogoliubov transformations lacks physical meaning until the external field vanishes. To address this, we explore dynamical quantities that remain well-defined at both asymptotic and intermediate times, focusing on the vacuum polarization current. Investigating this observable provides insights into the system's intermediate-time behavior. We consider pair creation in a spatially homogeneous, time-dependent, intense Sauter field. Specifically, we analyze the real and imaginary parts of the correlation function, linking them to vacuum polarization effects. The vacuum polarization current in an intense laser pulse is computed numerically, revealing that it correlates with the real part of the correlation function. Initially, the current changes sign and gradually decreases, but unlike the particle number, it does not reach a constant asymptotic value. Instead, for large times, it exhibits nearly undamped oscillations, a distinctive feature of scalar particles, oscillating strongly around zero. Additionally, we explore the uniqueness of the vacuum polarization current in the adiabatic basis, comparing different reference mode function choices. Notably, we find that the current remains independent of the basis choice. △ Less

Submitted 29 March, 2025; originally announced March 2025.

Feasibility of measuring the speed of sound of the quark-gluon plasma from the multiplicity and mean $p_T$ of ultracentral heavy-ion collisions

Authors: Lorenzo Gavassino, Henry Hirvonen, Jean-François Paquet, Mayank Singh, Gabriel Soares Rocha

Abstract: The mean transverse momentum $\langle p_T \rangle$ of hadrons has been observed experimentally and in numerical simulations to have a power-law dependence on the hadronic multiplicity $N$ in ultracentral relativistic heavy-ion collisions: $\langle p_{T} \rangle \propto N^{b_{\rm UC}}$. It has been put forward that this exponent $b_{\rm UC}$ is the speed of sound of quark-gluon plasma measured at a… ▽ More The mean transverse momentum $\langle p_T \rangle$ of hadrons has been observed experimentally and in numerical simulations to have a power-law dependence on the hadronic multiplicity $N$ in ultracentral relativistic heavy-ion collisions: $\langle p_{T} \rangle \propto N^{b_{\rm UC}}$. It has been put forward that this exponent $b_{\rm UC}$ is the speed of sound of quark-gluon plasma measured at a temperature determined from $\langle p_T \rangle$. We study step by step the connection between (i) the energy and entropy of hydrodynamic simulations and (ii) experimentally measurable observables. We show that an argument based on energy and entropy should yield an exponent equal to the pressure over energy density $P/\varepsilon$, rather than the speed of sound $c_s^2$; however, we also observe that $\langle p_T \rangle$ and $N$ are not sufficiently accurate proxies for the energy and entropy to make this possible in practice. From simulations, we find that the exponent $b_{\rm UC}$ is significantly different whether the ''effective volume'' is strictly constant or not, a condition that cannot be enforced experimentally. Additional tests using a modified equation of state find that the exponent $b_{\rm UC}$ exhibits a variable degree of correlations with the speed of sound and with $P/\varepsilon$, but is not an accurate measurement of either quantity in general. △ Less

Submitted 8 October, 2025; v1 submitted 26 March, 2025; originally announced March 2025.

Comments: 8 pages, 4 figures -- v4: version accepted for publication

3+1 neutrino mixings model with $A_4$ triplet Majorana neutrino

Authors: Mayengbam Kishan Singh, N. Nimai Singh

Abstract: We study a 3+1 active-sterile neutrino mixings model using an $A_4$ triplet right-handed neutrino $ν_R$ and a singlet eV-scale sterile neutrino under $A_4\times Z_3 \times Z_2$ discrete symmetry. Four scalar flavons are considered to reproduce neutrino oscillation parameters within the experimental 3$σ$ range. The model also studies the effective mass parameter in neutrinoless double beta decay ex… ▽ More We study a 3+1 active-sterile neutrino mixings model using an $A_4$ triplet right-handed neutrino $ν_R$ and a singlet eV-scale sterile neutrino under $A_4\times Z_3 \times Z_2$ discrete symmetry. Four scalar flavons are considered to reproduce neutrino oscillation parameters within the experimental 3$σ$ range. The model also studies the effective mass parameter in neutrinoless double beta decay experiments. Deviation from $μ-τ$ symmetry in the active neutrino mass matrix is generated through an antisymmetric interaction of $ν_R$. This model successfully explains active-sterile neutrino mixings consistent with the cosmological upper bound on the sum of active neutrino mass $\sum m_i < 0.113$ eV (0.145 eV) in NH(IH). △ Less

Submitted 17 March, 2025; originally announced March 2025.

Comments: 16 pages, 4 figures

Dynamical Scaling in Pair Production for Scalar QED

Authors: Deepak Sah, Manoranjan P. Singh

Abstract: We report on the dynamical scaling of momentum spectra for particle-antiparticle pairs at finite times within the framework of scalar Quantum Electrodynamics (QED). The analysis focuses on the momentum spectra in two different choices of adiabatic mode functions, which are related by a Wronskian normalization condition. Oscillations in the momentum spectra are attributed to quantum interference ef… ▽ More We report on the dynamical scaling of momentum spectra for particle-antiparticle pairs at finite times within the framework of scalar Quantum Electrodynamics (QED). The analysis focuses on the momentum spectra in two different choices of adiabatic mode functions, which are related by a Wronskian normalization condition. Oscillations in the momentum spectra are attributed to quantum interference effects in the adiabatic number basis. A novel dynamical scaling behavior emerges when examining the oscillatory momentum spectra of pairs created by a Sauter pulsed field at intermediate times. While the oscillatory spectra are observed at distinct times in the two different choices, they overlap when time is rescaled by the point marking the initiation of the first occurrence of the Residual ParticleAntiparticle Plasma (RPAP) stage (or end of the transient stage) for the central momentum case. This scaling identifies the approximate time at which real particle-antiparticle pair formation becomes possible, shifting the focus from asymptotic times to finite-time dynamics. Additionally, in the multi-photon regime, we find that the momentum spectra exhibit a multi-modal profile structure at finite times, consistent across both choices and also follow the dynamical scaling in this case as well. △ Less

Submitted 28 February, 2025; originally announced March 2025.

Comments: arXiv admin note: substantial text overlap with arXiv:2410.16321

Constraints on New Physics with Light Mediators and Generalized Neutrino Interactions via Coherent Elastic Neutrino Nucleus Scattering

Authors: S. Karadağ, M. Deniz, S. Karmakar, M. K. Singh, M. Demirci, Greeshma C., H. B. Li, S. T. Lin, M. F. Mustamin, V. Sharma, L. Singh, M. K. Singh, V. Singh, H. T. Wong

Abstract: We investigate new physics effects on coherent elastic neutrino nucleus scattering within the framework of nonstandard interactions and generalized neutrino interactions. Additionally, we examine the possibility of light mediators from a simplified model that includes all possible Lorentz-invariant interactions of vector, axialvector, scalar, pseudoscalar, and tensor types. Constraints and allowed… ▽ More We investigate new physics effects on coherent elastic neutrino nucleus scattering within the framework of nonstandard interactions and generalized neutrino interactions. Additionally, we examine the possibility of light mediators from a simplified model that includes all possible Lorentz-invariant interactions of vector, axialvector, scalar, pseudoscalar, and tensor types. Constraints and allowed regions at the $90\%$ CL for masses and couplings in each new physics scenario have been obtained through the analysis of TEXONO data, which includes two datasets from a high-purity $n$-type point contact germanium detector in 2016 and an advanced $p$-type point contact Ge detector in 2025. The results are presented in comparison with other reactor and accelerator-based neutrino experiments for complementarity. △ Less

Submitted 4 September, 2025; v1 submitted 27 February, 2025; originally announced February 2025.

Comments: 28 pages, 20 figures

Journal ref: Phys. Rev. D , 112, 035038 (2025)

Comprehensive Analysis of Thermal Dissipation in Lithium-Ion Battery Packs

Authors: Xuguang Zhang, Hexiang Zhang, Amjad Almansour, Mrityunjay Singh, Hengling Zhu, Michael C. Halbig, Yi Zheng

Abstract: Effective thermal management is critical for lithium-ion battery packs' safe and efficient operations, particularly in applications such as drones, where compact designs and varying airflow conditions present unique challenges. This study investigates the thermal performance of a 16-cell lithium-ion battery pack by optimizing cooling airflow configurations and integrating phase change materials (P… ▽ More Effective thermal management is critical for lithium-ion battery packs' safe and efficient operations, particularly in applications such as drones, where compact designs and varying airflow conditions present unique challenges. This study investigates the thermal performance of a 16-cell lithium-ion battery pack by optimizing cooling airflow configurations and integrating phase change materials (PCMs) for enhanced heat dissipation. Seven geometric configurations were evaluated under airflow speeds ranging from 0 to 15 m/s, reflecting the operational conditions of civilian drones. A comprehensive 3D simulation approach was used to analyze the effects of inlet and outlet configurations, airflow dynamics, and PCM phase transition behavior. Results indicate that the trapezoidal (wide-base) configuration, paired with a 5-inlet and 1-outlet setup, achieves the most balanced performance, effectively maintaining optimal operating temperatures across low and high-speed airflow conditions. PCM integration further stabilized thermal behavior, with phase change durations extending to 12.5 min under tested conditions. These findings highlight the importance of geometric optimization and material integration in advancing compact and reliable thermal management systems for energy-dense battery packs. This study provides a foundation for designing efficient cooling strategies tailored to lightweight applications such as drones and portable energy storage systems. △ Less

Submitted 10 February, 2025; originally announced February 2025.

Comments: 20 pages, five figures, introduced the thermal management of Lithium-ion battery

Hybrid Hadronization -- A Study of In-Medium Hadronization of Jets

Authors: A. Sengupta, R. J. Fries, M. Kordell II, B. Kim, A. Angerami, R. Arora, S. A. Bass, Y. Chen, R. Datta, L. Du, R. Ehlers, H. Elfner, C. Gale, Y. He, B. V. Jacak, P. M. Jacobs, S. Jeon, Y. Ji, F. Jonas, L. Kasper, A. Kumar, R. Kunnawalkam-Elayavalli, J. Latessa, Y. -J. Lee, R. Lemmon , et al. (28 additional authors not shown)

Abstract: QCD jets are considered important probes for quark gluon plasma created in collisions of nuclei at high energies. Their parton showers are significantly altered if they develop inside of a deconfined medium. Hadronization of jets is also thought to be affected by the presence of quarks and gluons. We present a systematic study of the effects of a thermal bath of partons on the hadronization of par… ▽ More QCD jets are considered important probes for quark gluon plasma created in collisions of nuclei at high energies. Their parton showers are significantly altered if they develop inside of a deconfined medium. Hadronization of jets is also thought to be affected by the presence of quarks and gluons. We present a systematic study of the effects of a thermal bath of partons on the hadronization of parton showers. We use the JETSCAPE framework to create parton showers both in vacuum and in a brick of quark gluon plasma. The brick setup allows important parameters, like the size of the plasma as well as the collective flow of partons, to be varied systematically. We hadronize the parton showers using Hybrid Hadronization, which permits shower partons to form strings with thermal partons, or to recombine directly with thermal partons as well as with each other. We find a sizeable amount of interaction of shower partons with thermal partons during hadronization, indicating a natural continuation of the interaction of jet and medium during this stage. The observed effects grow with the size of the medium. Collective flow easily transfers from the thermal partons onto the emerging jet hadrons. We also see a significant change in hadron chemistry as expected in the presence of quark recombination processes. △ Less

Submitted 27 January, 2025; originally announced January 2025.

Comments: 12 pages, 6 figures

A plethora of long-range neutrino interactions probed by DUNE and T2HK

Authors: Sanjib Kumar Agarwalla, Mauricio Bustamante, Masoom Singh, Pragyanprasu Swain

Abstract: The next-generation neutrino oscillation experiments would be sensitive to the new neutrino interactions that would strengthen the search for physics beyond the Standard Model. In this context, we explore the capabilities of the two leading future long-baseline neutrino oscillation experiments, DUNE and T2HK, to search for new flavor-dependent neutrino interactions with electrons, protons, and neu… ▽ More The next-generation neutrino oscillation experiments would be sensitive to the new neutrino interactions that would strengthen the search for physics beyond the Standard Model. In this context, we explore the capabilities of the two leading future long-baseline neutrino oscillation experiments, DUNE and T2HK, to search for new flavor-dependent neutrino interactions with electrons, protons, and neutrons that could potentially modify neutrino flavor transitions. We forecast their sensitivities in the context of long-range neutrino interactions mediated by a neutral vector boson lighter than $10^{-10}$ eV and sourced by the vast amount of nearby and distant matter in the Earth, Moon, Sun, Milky Way, and local Universe. For the first time, we explore a plethora of $U(1)^\prime$ symmetries inducing the new interactions built from the combination of lepton and baryon numbers. We find that in all cases, DUNE and T2HK may constrain or discover the existence of new long-range neutrino interaction, and in some favorable cases, may identify the new $U(1)^\prime$ symmetry responsible for it. In this short proceeding, we only summarize the prospects of constraining the new interaction in case of all our candidate $U(1)^\prime$ symmetries, which have been discussed in JHEP 09 (2024) 055. △ Less

Submitted 23 January, 2025; originally announced January 2025.

Comments: 4 pages, 3 figures, and 1 table. Conference proceedings for the 25th International Workshop on Neutrinos from Accelerators (NuFact 2024)

Report number: NuFact 2024-30

Flavor-Dependent Long-Range Neutrino Interactions in DUNE and T2HK: Synergy Breeds Power

Authors: Masoom Singh, Mauricio Bustamante, Sanjib Kumar Agarwalla

Abstract: Discovering new neutrino interactions would provide evidence of physics beyond the Standard Model. We focus on flavor-dependent long-range neutrino interactions mediated by ultra-light mediators (masses below $10^{-10}$ eV) from lepton-number gauge symmetries $L_e-L_μ$, $L_e-L_τ$, and $L_μ-L_τ$. These interactions, sourced by electrons and neutrons in the Earth, Moon, Sun, Milky Way, and the local… ▽ More Discovering new neutrino interactions would provide evidence of physics beyond the Standard Model. We focus on flavor-dependent long-range neutrino interactions mediated by ultra-light mediators (masses below $10^{-10}$ eV) from lepton-number gauge symmetries $L_e-L_μ$, $L_e-L_τ$, and $L_μ-L_τ$. These interactions, sourced by electrons and neutrons in the Earth, Moon, Sun, Milky Way, and the local Universe, could modify neutrino oscillation probabilities. The upcoming long-baseline experiments, DUNE and T2HK, with their large statistics, reduced systematic uncertainties, and well-characterized neutrino beams, will probe these interactions. We forecast that, while individually DUNE and T2HK could constrain these long-range neutrino interactions, their combination lifts parameter degeneracies that weaken individual sensitivity and provides stronger constraints. △ Less

Submitted 21 January, 2025; originally announced January 2025.

Comments: 4 pages and 3 figures. Conference proceedings for the 25th International Workshop on Neutrinos from Accelerators (NuFact 2024)

Report number: NuFact 2024-29

Hard Photon Triggered Jets in $p$-$p$ and $A$-$A$ Collisions

Authors: C. Sirimanna, Y. Tachibana, A. Majumder, A. Angerami, R. Arora, S. A. Bass, Y. Chen, R. Datta, L. Du, R. Ehlers, H. Elfner, R. J. Fries, C. Gale, Y. He, B. V. Jacak, P. M. Jacobs, S. Jeon, Y. Ji, F. Jonas, L. Kasper, M. Kordell II, A. Kumar, R. Kunnawalkam-Elayavalli, J. Latessa, Y. -J. Lee , et al. (27 additional authors not shown)

Abstract: An investigation of high transverse momentum (high-$p_T$) photon triggered jets in proton-proton ($p$-$p$) and ion-ion ($A$-$A$) collisions at $\sqrt{s_{NN}} = 0.2$ and $5.02~\mathrm{TeV}$ is carried out, using the multistage description of in-medium jet evolution. Monte Carlo simulations of hard scattering and energy loss in heavy-ion collisions are performed using parameters tuned in a previous… ▽ More An investigation of high transverse momentum (high-$p_T$) photon triggered jets in proton-proton ($p$-$p$) and ion-ion ($A$-$A$) collisions at $\sqrt{s_{NN}} = 0.2$ and $5.02~\mathrm{TeV}$ is carried out, using the multistage description of in-medium jet evolution. Monte Carlo simulations of hard scattering and energy loss in heavy-ion collisions are performed using parameters tuned in a previous study of the nuclear modification factor ($R_{AA}$) for inclusive jets and high-$p_T$ hadrons. We obtain a good reproduction of the experimental data for photon triggered jet $R_{AA}$, as measured by the ATLAS detector, the distribution of the ratio of jet to photon $p_T$ ($X_{\rm J γ}$), measured by both CMS and ATLAS, and the photon-jet azimuthal correlation as measured by CMS. We obtain a moderate description of the photon triggered jet $I_{AA}$, as measured by STAR. A noticeable improvement in the comparison is observed when one goes beyond prompt photons and includes bremsstrahlung and decay photons, revealing their significance in certain kinematic regions, particularly at $X_{Jγ} > 1$. Moreover, azimuthal angle correlations demonstrate a notable impact of non-prompt photons on the distribution, emphasizing their role in accurately describing experimental results. This work highlights the success of the multistage model of jet modification to straightforwardly predict (this set of) photon triggered jet observables. This comparison, along with the role played by non-prompt photons, has important consequences on the inclusion of such observables in a future Bayesian analysis. △ Less

Submitted 27 December, 2024; originally announced December 2024.

Comments: 16 pages, 10 figures

New Limits on Coherent Neutrino Nucleus Elastic Scattering Cross Section at the Kuo-Sheng Reactor Neutrino Laboratory

Authors: TEXONO Collaboration, S. Karmakar, M. K. Singh, V. Sharma, H. T. Wong, Greeshma C., H. B. Li, L. Singh, M. Agartioglu, J. H. Chen, C. I. Chiang, M. Deniz, H. C. Hsu, S. Karadag, V. Kumar, C. H. Leung, J. Li, F. K. Lin, S. T. Lin, S. K. Liu, H. Ma, K. Saraswat, M. K. Singh, V. Singh, D. Tanabe , et al. (4 additional authors not shown)

Abstract: Neutrino nucleus elastic scattering (νAel) with reactor neutrinos is an interaction under full quantum-mechanical coherence. It has not yet been experimentally observed. We present new results on the studies of νAel cross section with an electro-cooled p-type point-contact germanium detector at the Kuo-Sheng Reactor Neutrino laboratory. A total of (242)357 kg-days of Reactor ON(OFF) data at a dete… ▽ More Neutrino nucleus elastic scattering (νAel) with reactor neutrinos is an interaction under full quantum-mechanical coherence. It has not yet been experimentally observed. We present new results on the studies of νAel cross section with an electro-cooled p-type point-contact germanium detector at the Kuo-Sheng Reactor Neutrino laboratory. A total of (242)357 kg-days of Reactor ON(OFF) data at a detector threshold of 200 eVee in electron equivalent unit are analyzed. The Lindhard model parametrized by a single variable k which characterizes the quenching function was used. Limits at 90% confidence level are derived on the ratio ρ relative to standard model (SM) cross section of ρ<4.7 at the predicted value of k=0.162, while k<0.285 at the SM-value of ρ=1. Prospects on future positive measurements are discussed. △ Less

Submitted 7 April, 2025; v1 submitted 27 November, 2024; originally announced November 2024.

Comments: 6 pages, 4 figures

Journal ref: Phys.Rev.Lett. 134 (2025) 12, 121802

Does the oscillatory behavior of the Momentum Spectrum depend on the basis in the Post-Transient Stage?

Authors: Deepak Sah, Manoranjan P. Singh

Abstract: Pair creation by a spatially homogeneous, time-dependent electric field is studied within the framework of scalar quantum electrodynamics. We employ the standard Bogoliubov transformation approach to compute the single-particle distribution function in an adiabatic basis. We analyzed the distribution function of created particles in two different adiabatic bases (related by a unitary transformatio… ▽ More Pair creation by a spatially homogeneous, time-dependent electric field is studied within the framework of scalar quantum electrodynamics. We employ the standard Bogoliubov transformation approach to compute the single-particle distribution function in an adiabatic basis. We analyzed the distribution function of created particles in two different adiabatic bases (related by a unitary transformation). A novel dynamical scaling is observed while analyzing the oscillatory momentum spectrum of the pairs created by the Sauter pulsed field at intermediate times, calculated using the two adiabatic bases. In these bases, the same oscillatory momentum spectra are observed but at different times. However, when we scale the time by the point marking the end of the transient stage of dynamical evolution for each case of central momentum, the respective momentum spectra overlap. Furthermore, we study the time evolution of the momentum spectrum in the multi-photon regime and find that the spectra show a multi-modal profile structure at finite times for both choices of basis. △ Less

Submitted 24 January, 2025; v1 submitted 17 October, 2024; originally announced October 2024.

Comments: The research analysis in the current version of the paper is not fully up to the mark, and some mistakes have been identified that require correction

Spinodal decomposition in Bjorken flow

Authors: Joseph Kapusta, Mayank Singh, Thomas Welle

Abstract: The QCD first-order phase transition at large baryon densities is expected to proceed by spinodal decomposition. This spinodal phase is likely to leave its signatures on the experimental observables measured in heavy-ion collision experiments. Identifying these signatures requires phenomenological models integrating surface effects resulting from the phase transition into the hydrodynamical descri… ▽ More The QCD first-order phase transition at large baryon densities is expected to proceed by spinodal decomposition. This spinodal phase is likely to leave its signatures on the experimental observables measured in heavy-ion collision experiments. Identifying these signatures requires phenomenological models integrating surface effects resulting from the phase transition into the hydrodynamical description of the expanding quark gluon plasma. We write the equations of relativistic hydrodynamics with spinodal decomposition and solve it in on a background of Bjorken flow relevant for heavy-ion collisions. △ Less

Submitted 24 September, 2024; originally announced September 2024.

Comments: 4 pages, 3 figures, Proceedings for the 21st International Conference on Strangeness in Quark Matter, 2024

Disoriented isospin condensates in heavy-ion collisions

Authors: Joseph Kapusta, Scott Pratt, Mayank Singh

Abstract: Anomalous neutral to charged kaon correlations measured by the ALICE collaboration have defied usual explanations. We propose that the large fluctuations could arise because of a disoriented isospin condensate where there is an imbalance between up and down condensates at the time kaons hadronize. This could happen in heavy-ion collisions when the quark condensate re-forms as the system cools and… ▽ More Anomalous neutral to charged kaon correlations measured by the ALICE collaboration have defied usual explanations. We propose that the large fluctuations could arise because of a disoriented isospin condensate where there is an imbalance between up and down condensates at the time kaons hadronize. This could happen in heavy-ion collisions when the quark condensate re-forms as the system cools and the approximate chiral symmetry of QCD is broken. Within the linear sigma model, we show that the energy cost of forming a disoriented isospin condensate is small making it very plausible. △ Less

Submitted 24 September, 2024; originally announced September 2024.

Comments: 4 pages, 3 figures, Proceedings for the 21st International Conference on Strangeness in Quark Matter, 2024

Simulating Charm Quarks in IP-Glasma Initial Stage and Quark-Gluon Plasma: A Hybrid Approach for charm quark phenomenology

Authors: Charles Gale, Sangyong Jeon, Manu Kurian, Björn Schenke, Mayank Singh

Abstract: We present phenomenological findings on charm quark transport while including its energy loss in both pre-equilibrium and hydrodynamic stages of the evolution. We employed the MARTINI event generator for the production and evolution of heavy quarks in the relativistic heavy-ion collisions. The sensitivity of the heavy meson nuclear modification factor and flow coefficient to the early stage of hea… ▽ More We present phenomenological findings on charm quark transport while including its energy loss in both pre-equilibrium and hydrodynamic stages of the evolution. We employed the MARTINI event generator for the production and evolution of heavy quarks in the relativistic heavy-ion collisions. The sensitivity of the heavy meson nuclear modification factor and flow coefficient to the early stage of heavy-ion collisions and bulk medium evolution is analyzed for Pb+Pb collisions at 5.02 TeV. Our study provides insights into the interaction strength of charm quarks during the early phase and within the quark-gluon plasma. △ Less

Submitted 23 September, 2024; originally announced September 2024.

Comments: 4 pages, 3 figures, Conference proceedings for 21st International Conference on Strangeness in Quark Matter (SQM2024), Strasbourg (France), June 3-7, 2024

Relaxation times for disoriented isospin condensates in high energy heavy ion collisions

Authors: Olivia Chabowski, Joseph I. Kapusta, Mayank Singh

Abstract: Fluctuations between charged and neutral kaons measured by the ALICE Collaboration in Pb-Pb collisions at the LHC exceed conventional explanations. Previously it was shown that if the scalar condensate is accompanied by an electrically neutral isospin--1 field then the combination can produce large equilibrium fluctuations where $\langle \bar{u}u\rangle \ne \langle \bar{d}d\rangle$. Hadronizing st… ▽ More Fluctuations between charged and neutral kaons measured by the ALICE Collaboration in Pb-Pb collisions at the LHC exceed conventional explanations. Previously it was shown that if the scalar condensate is accompanied by an electrically neutral isospin--1 field then the combination can produce large equilibrium fluctuations where $\langle \bar{u}u\rangle \ne \langle \bar{d}d\rangle$. Hadronizing strange and anti-strange quarks might then strongly fluctuate between charged ($u\bar{s}$ or $s\bar{u}$) and neutral ($d\bar{s}$ or $s\bar{d}$) kaons. Here we estimate the times for the condensates to achieve their equilibrium probability distributions within causal volumes in high energy heavy ion collisions. This is achieved by modeling the temperature dependence of the condensates, mesonic collective excitations, decay rates of the associated fields, and employing the Langevin and Fokker-Planck equations. Within this model, we find that the equilibration times are short compared with the expansion time, making disoriented isospin condensates a viable explanation for the anomalous fluctuations observed at the LHC. △ Less

Submitted 21 July, 2025; v1 submitted 5 September, 2024; originally announced September 2024.

Comments: Fixes errors in eq. 67 and 68 and replaces figures 9 and 10, as reported in the erratum to appear in Phys. Rev. C; 27 pages, 12 figures

Journal ref: Phys. Rev. C 111, 024903 (2025)

Improved precision on 2-3 oscillation parameters using the synergy between DUNE and T2HK

Authors: Sanjib Kumar Agarwalla, Ritam Kundu, Masoom Singh

Abstract: A high-precision measurement of $Δm^2_{31}$ and $θ_{23}$ is inevitable to estimate the Earth's matter effect in long-baseline experiments which in turn plays an important role in addressing the issue of neutrino mass ordering and to measure the value of CP phase in $3ν$ framework. After reviewing the results from the past and present experiments, and discussing the near-future sensitivities from t… ▽ More A high-precision measurement of $Δm^2_{31}$ and $θ_{23}$ is inevitable to estimate the Earth's matter effect in long-baseline experiments which in turn plays an important role in addressing the issue of neutrino mass ordering and to measure the value of CP phase in $3ν$ framework. After reviewing the results from the past and present experiments, and discussing the near-future sensitivities from the IceCube Upgrade and KM3NeT/ORCA, we study the expected improvements in the precision of 2-3 oscillation parameters that the next-generation long-baseline experiments, DUNE and T2HK, can bring either in isolation or combination. We highlight the relevance of the possible complementarities between these two experiments in obtaining the improved sensitivities in determining the deviation from maximal mixing of $θ_{23}$, excluding the wrong-octant solution of $θ_{23}$, and obtaining high precision on 2-3 oscillation parameters, as compared to their individual performances. We observe that for the current best-fit values of the oscillation parameters and assuming normal mass ordering (NMO), DUNE + T2HK can establish the non-maximal $θ_{23}$ and exclude the wrong octant solution of $θ_{23}$ at around 7$σ$ C.L. with their nominal exposures. We find that DUNE + T2HK can improve the current relative 1$σ$ precision on $\sin^{2}θ_{23}~(Δm^{2}_{31})$ by a factor of 7 (5) assuming NMO. Also, we notice that with less than half of their nominal exposures, the combination of DUNE and T2HK can achieve the sensitivities that are expected from these individual experiments using their full exposures. We also portray how the synergy between DUNE and T2HK can provide better constraints on ($\sin^2θ_{23}$ - $δ_{\mathrm{CP}}$) plane as compared to their individual reach. △ Less

Submitted 22 August, 2024; originally announced August 2024.

Comments: 28 pages, 11 figures, and 4 tables. Comments are welcome

Report number: IP/BBSR/2024-04

Journal ref: JHEP 10 (2024) 243

Bayesian Inference analysis of jet quenching using inclusive jet and hadron suppression measurements

Authors: R. Ehlers, Y. Chen, J. Mulligan, Y. Ji, A. Kumar, S. Mak, P. M. Jacobs, A. Majumder, A. Angerami, R. Arora, S. A. Bass, R. Datta, L. Du, H. Elfner, R. J. Fries, C. Gale, Y. He, B. V. Jacak, S. Jeon, F. Jonas, L. Kasper, M. Kordell II, R. Kunnawalkam-Elayavalli, J. Latessa, Y. -J. Lee , et al. (28 additional authors not shown)

Abstract: The JETSCAPE Collaboration reports a new determination of the jet transport parameter $\hat{q}$ in the Quark-Gluon Plasma (QGP) using Bayesian Inference, incorporating all available inclusive hadron and jet yield suppression data measured in heavy-ion collisions at RHIC and the LHC. This multi-observable analysis extends the previously published JETSCAPE Bayesian Inference determination of… ▽ More The JETSCAPE Collaboration reports a new determination of the jet transport parameter $\hat{q}$ in the Quark-Gluon Plasma (QGP) using Bayesian Inference, incorporating all available inclusive hadron and jet yield suppression data measured in heavy-ion collisions at RHIC and the LHC. This multi-observable analysis extends the previously published JETSCAPE Bayesian Inference determination of $\hat{q}$, which was based solely on a selection of inclusive hadron suppression data. JETSCAPE is a modular framework incorporating detailed dynamical models of QGP formation and evolution, and jet propagation and interaction in the QGP. Virtuality-dependent partonic energy loss in the QGP is modeled as a thermalized weakly-coupled plasma, with parameters determined from Bayesian calibration using soft-sector observables. This Bayesian calibration of $\hat{q}$ utilizes Active Learning, a machine--learning approach, for efficient exploitation of computing resources. The experimental data included in this analysis span a broad range in collision energy and centrality, and in transverse momentum. In order to explore the systematic dependence of the extracted parameter posterior distributions, several different calibrations are reported, based on combined jet and hadron data; on jet or hadron data separately; and on restricted kinematic or centrality ranges of the jet and hadron data. Tension is observed in comparison of these variations, providing new insights into the physics of jet transport in the QGP and its theoretical formulation. △ Less

Submitted 28 August, 2024; v1 submitted 15 August, 2024; originally announced August 2024.

Comments: 20 pages, 10 figures, 2 tables, submitted to PRC; updated acknowledgements

Journal ref: Phys.Rev.C 111 (2025) 5, 054913

A soft-hard framework with exact four momentum conservation for small systems

Authors: I. Soudi, W. Zhao, A. Majumder, C. Shen, J. H. Putschke, B. Boudreaux, A. Angerami, R. Arora, S. A. Bass, Y. Chen, R. Datta, L. Du, R. Ehlers, H. Elfner, R. J. Fries, C. Gale, Y. He, B. V. Jacak, P. M. Jacobs, S. Jeon, Y. Ji, L. Kasper, M. Kelsey, M. Kordell II, A. Kumar , et al. (28 additional authors not shown)

Abstract: A new framework, called x-scape, for the combined study of both hard and soft transverse momentum sectors in high energy proton-proton ($p$-$p$) and proton-nucleus ($p$-$A$) collisions is set up. A dynamical initial state is set up using the 3d-Glauber model with transverse locations of hotspots within each incoming nucleon. A hard scattering that emanates from two colliding hotspots is carried ou… ▽ More A new framework, called x-scape, for the combined study of both hard and soft transverse momentum sectors in high energy proton-proton ($p$-$p$) and proton-nucleus ($p$-$A$) collisions is set up. A dynamical initial state is set up using the 3d-Glauber model with transverse locations of hotspots within each incoming nucleon. A hard scattering that emanates from two colliding hotspots is carried out using the Pythia generator. Initial state radiation from the incoming hard partons is carried out in a new module called I-matter, which includes the longitudinal location of initial splits. The energy-momentum of both the initial hard partons and their associated beam remnants is removed from the hot spots, depleting the energy-momentum available for the formation of the bulk medium. Outgoing showers are simulated using the matter generator, and results are presented for both cases, allowing for and not allowing for energy loss. First comparisons between this hard-soft model and single inclusive hadron and jet data from $p$-$p$ and minimum bias $p$-$Pb$ collisions are presented. Single hadron spectra in $p$-$p$ are used to carry out a limited (in number of parameters) Bayesian calibration of the model. Fair comparisons with data are indicative of the utility of this new framework. Theoretical studies of the correlation between jet $p_T$ and event activity at mid and forward rapidity are carried out. △ Less

Submitted 24 July, 2024; originally announced July 2024.

Comments: 18 pages, 15 figures

Covariant formulation of spinodal decomposition in rapidly expanding quark gluon plasma

Authors: Joseph I. Kapusta, Mayank Singh, Thomas Welle

Abstract: Quantum Chromodynamics (QCD) is expected to have a first order phase transition between the confined hadron gas and the deconfined quark gluon plasma at high baryon densities. This will result in phase boundary effects in the metastable and unstable regions. It is important to include these effects in phenomenological models of heavy ion collisions to identify experimental signatures of a phase tr… ▽ More Quantum Chromodynamics (QCD) is expected to have a first order phase transition between the confined hadron gas and the deconfined quark gluon plasma at high baryon densities. This will result in phase boundary effects in the metastable and unstable regions. It is important to include these effects in phenomenological models of heavy ion collisions to identify experimental signatures of a phase transition. This requires building intuition on phase separation in rapidly expanding fluids. In this work we present the covariant equations of relativistic hydrodynamics with a phase boundary, provide prescriptions to extend the equation of state to metastable and unstable regions, and show the effects of spinodal separation in a Bjorken flow. △ Less

Submitted 8 November, 2024; v1 submitted 23 July, 2024; originally announced July 2024.

Comments: 19 pages, 7 figures; Matches version published in Phys. Rev. C

Journal ref: Phys. Rev. C 110, 054902 (2024)

Exploring active-sterile neutrino mixings models in MES mechanism using modular $S_3$ symmetry

Authors: Mayengbam Kishan Singh, N. Nimai Singh

Abstract: We study the minimal extended seesaw mechanism with one sterile neutrino in a 3+1 framework using modular $S_3$ symmetry. The active-sterile neutrino models are classified based on the assignments of $S_3$ representations and modular weights of the left-handed lepton doublets, triplet right-handed neutrino, and sterile neutrino. No scalar flavons are considered, and the flavor symmetry is broken b… ▽ More We study the minimal extended seesaw mechanism with one sterile neutrino in a 3+1 framework using modular $S_3$ symmetry. The active-sterile neutrino models are classified based on the assignments of $S_3$ representations and modular weights of the left-handed lepton doublets, triplet right-handed neutrino, and sterile neutrino. No scalar flavons are considered, and the flavor symmetry is broken by the vacuum expectation value (vev) of the modulus $τ$. For a particular set of representations of the Leptons and Higgs field, we obtain eleven (11) different models based on different modular weights of charged lepton $(k_L)$ and right-handed neutrino ($k_N$). Out of these, we consider two models, which are discriminated by carrying out the numerical analysis so that the parameter space in each model can fit the latest neutrino oscillation data at 3$σ$. The Planck cosmological bound on the upper limit of the sum of the active neutrino masses $\sum m_i <0.12$eV is also considered. Finally, the best-fit parameters of the neutrino observables and model predictions are evaluated using the minimum $χ^2$ analysis. △ Less

Submitted 21 December, 2024; v1 submitted 5 June, 2024; originally announced June 2024.

Comments: Errors in the mass matrices. Will be updated

Analytical insights into the interplay of momentum, multiplicity and the speed of sound in heavy-ion collisions

Authors: Gabriel Soares Rocha, Lorenzo Gavassino, Mayank Singh, Jean-François Paquet

Abstract: We introduce a minimal model of ultracentral heavy-ion collisions to study the relation between the speed of sound of the produced plasma and the final particles' energy and multiplicity. We discuss how the particles' multiplicity $N_{\textrm{tot}}$ and average energy $E_{\textrm{tot}}/N_{\textrm{tot}}$ is related to the speed of sound $c_s$ by… ▽ More We introduce a minimal model of ultracentral heavy-ion collisions to study the relation between the speed of sound of the produced plasma and the final particles' energy and multiplicity. We discuss how the particles' multiplicity $N_{\textrm{tot}}$ and average energy $E_{\textrm{tot}}/N_{\textrm{tot}}$ is related to the speed of sound $c_s$ by $c_s^2=d \ln (E_{\textrm{tot}}/N_{\textrm{tot}})/d\ln N_{\textrm{tot}}$ if the fluid is inviscid, its speed of sound is constant and all final particles can be measured. We show that finite rapidity cuts on the particles' multiplicity $N$ and energy $E$ introduce corrections between $c_s^2$ and $d \ln (E/N)/d\ln N$ that depend on the system's lifetime. We study analytically these deviations with the Gubser hydrodynamic solution, finding that, for ultrarelativistic bosons, they scale as the ratio of the freezeout temperature $T_{\mathrm{FO}}$ over the maximum initial temperature of the fluid $T_{0}$; the non-thermodynamic aspect of these corrections is highlighted through their dependence on the system's initial conditions. △ Less

Submitted 30 September, 2024; v1 submitted 16 May, 2024; originally announced May 2024.

Comments: 21 pages, 8 figures, v2 -- published version, associated git-hub repository: https://github.com/gabriel-sr151/cylindrical-sym-CF

A randomly generated Majorana neutrino mass matrix using Adaptive Monte Carlo method

Authors: Y Monitar Singh, Mayengbam Kishan Singh, N Nimai Singh

Abstract: A randomly generated complex symmetric matrix using Adaptive Monte Carlo method, is taken as a general form of Majorana neutrino mass matrix, which is diagonalized by the use of eigenvectors. We extract all the neutrino oscillation parameters i.e. two mass-squared differences ($Δm_{21}^2$ and $Δm_{32}^2$ ), three mixing angles ($θ_{12}$, $θ_{13}$, $θ_{23}$) and three phases i.e. one Dirac CP viola… ▽ More A randomly generated complex symmetric matrix using Adaptive Monte Carlo method, is taken as a general form of Majorana neutrino mass matrix, which is diagonalized by the use of eigenvectors. We extract all the neutrino oscillation parameters i.e. two mass-squared differences ($Δm_{21}^2$ and $Δm_{32}^2$ ), three mixing angles ($θ_{12}$, $θ_{13}$, $θ_{23}$) and three phases i.e. one Dirac CP violating phase ($δ_{CP}$) and two Majorana phases ($α$ and $β$). The charge-parity (CP) violating phases are extracted from the mixing matrix constructed with the eigenvectors of the Hermitian matrix formed by the complex symmetric matrix. All the neutrino oscillation parameters within 3$σ$ bound are allowed in both normal hierarchy (NH) and inverted hierarchy (IH) consistent with the latest Planck cosmological upper bound, $\sum\vert m_i\vert<0.12$ eV. This latest cosmological upper bound is allowed only in three cases of zero texture for $m_{11}=0$; $m_{11},m_{12}=0$ and $m_{11},m_{13}=0$ in normal hierarchy whereas none of zero texture is allowed in inverted hierarchy. We also study effective neutrino masses $m_β$ in tritium beta decay and $m_{ββ}$ in neutrinoless double beta decay. △ Less

Submitted 27 July, 2024; v1 submitted 14 May, 2024; originally announced May 2024.

Comments: 23-pages, some text and extra figure are added

Search for solar axions by Primakoff effect with the full dataset of the CDEX-1B Experiment

Authors: L. T. Yang, S. K. Liu, Q. Yue, K. J. Kang, Y. J. Li, H. P. An, Greeshma C., J. P. Chang, Y. H. Chen, J. P. Cheng, W. H. Dai, Z. Deng, C. H. Fang, X. P. Geng, H. Gong, Q. J. Guo, T. Guo, X. Y. Guo, L. He, J. R. He, J. W. Hu, H. X. Huang, T. C. Huang, L. Jiang, S. Karmakar , et al. (61 additional authors not shown)

Abstract: We present the first limit on $g_{Aγ}$ coupling constant using the Bragg-Primakoff conversion based on an exposure of 1107.5 kg days of data from the CDEX-1B experiment at the China Jinping Underground Laboratory. The data are consistent with the null signal hypothesis, and no excess signals are observed. Limits of the coupling $g_{Aγ}<2.08\times10^{-9}$ GeV$^{-1}$ (95\% C.L.) are derived for axio… ▽ More We present the first limit on $g_{Aγ}$ coupling constant using the Bragg-Primakoff conversion based on an exposure of 1107.5 kg days of data from the CDEX-1B experiment at the China Jinping Underground Laboratory. The data are consistent with the null signal hypothesis, and no excess signals are observed. Limits of the coupling $g_{Aγ}<2.08\times10^{-9}$ GeV$^{-1}$ (95\% C.L.) are derived for axions with mass up to 100 eV/$c^2$. Within the hadronic model of KSVZ, our results exclude axion mass $>5.3~\rm{eV}/c^2$ at 95\% C.L. △ Less

Submitted 12 May, 2024; originally announced May 2024.

Comments: 7 pages, 5 figures

Longitudinal Momentum Spectra of pair created in a pulsed field at finite times: Are Oscillations "Real"

Authors: Deepak Sah, Manoranjan P. Singh

Abstract: We discuss the mechanism of production of electron-positron pairs from the vacuum in a time-varying, spatially uniform pulsed electric field. We analytically compute the probability of $(e^+ e^-) $pair production in momentum space using the exact solution of the one-particle time-dependent Dirac equation and compare the result with quantum kinetic theory (QKT). Both approaches allow us to study th… ▽ More We discuss the mechanism of production of electron-positron pairs from the vacuum in a time-varying, spatially uniform pulsed electric field. We analytically compute the probability of $(e^+ e^-) $pair production in momentum space using the exact solution of the one-particle time-dependent Dirac equation and compare the result with quantum kinetic theory (QKT). Both approaches allow us to study the particle momentum spectrum at any instant in time and can potentially unveil valuable information regarding quantum non-equilibrium physics. We analyze both approaches' momentum spectra of the created particles at any instant. We observe a multi-profile structure in the LMS. This multi-profile structure clearly illustrates the quantum interference effects associated with pair production. It is worth noting that both approaches exhibit quantum interference patterns at finite times, manifested as oscillations observed in the LMS. We highlight that this quantum signature is a universal behavior seen in the momentum spectra at finite times, where the electric field is nearly zero. △ Less

Submitted 10 July, 2025; v1 submitted 5 May, 2024; originally announced May 2024.

Comments: The manuscript requires substantial revision

First search for light fermionic dark matter absorption on electrons using germanium detector in CDEX-10 experiment

Authors: J. X. Liu, L. T. Yang, Q. Yue, K. J. Kang, Y. J. Li, H. P. An, Greeshma C., J. P. Chang, Y. H. Chen, J. P. Cheng, W. H. Dai, Z. Deng, C. H. Fang, X. P. Geng, H. Gong, Q. J. Guo, T. Guo, X. Y. Guo, L. He, J. R. He, J. W. Hu, H. X. Huang, T. C. Huang, L. Jiang, S. Karmakar , et al. (61 additional authors not shown)

Abstract: We present the first results of the search for sub-MeV fermionic dark matter absorbed by electron targets of germanium using the 205.4~kg$\cdot$day data collected by the CDEX-10 experiment, with the analysis threshold of 160~eVee. No significant dark matter (DM) signals over the background are observed. Results are presented as limits on the cross section of DM--electron interaction. We present ne… ▽ More We present the first results of the search for sub-MeV fermionic dark matter absorbed by electron targets of germanium using the 205.4~kg$\cdot$day data collected by the CDEX-10 experiment, with the analysis threshold of 160~eVee. No significant dark matter (DM) signals over the background are observed. Results are presented as limits on the cross section of DM--electron interaction. We present new constraints of cross section in the DM range of 0.1--10 keV/$c^2$ for vector and axial-vector interaction. The upper limit on the cross section is set to be $\rm 6.8\times10^{-46}~cm^2$ for vector interaction, and $\rm 2.3\times10^{-46}~cm^2$ for axial-vector interaction at DM mass of 5 keV/$c^2$. △ Less

Submitted 17 February, 2026; v1 submitted 15 April, 2024; originally announced April 2024.

Comments: 6 pages, 4 figures. Version updated to match PRD version

Journal ref: Phys. Rev. D 113, 032011 (2026)

A plethora of long-range neutrino interactions probed by DUNE and T2HK

Authors: Sanjib Kumar Agarwalla, Mauricio Bustamante, Masoom Singh, Pragyanprasu Swain

Abstract: Upcoming neutrino experiments will soon search for new neutrino interactions more thoroughly than ever before, boosting the prospects of extending the Standard Model. In anticipation of this, we forecast the capability of two of the leading long-baseline neutrino oscillation experiments, DUNE and T2HK, to look for new flavor-dependent neutrino interactions with electrons, protons, and neutrons tha… ▽ More Upcoming neutrino experiments will soon search for new neutrino interactions more thoroughly than ever before, boosting the prospects of extending the Standard Model. In anticipation of this, we forecast the capability of two of the leading long-baseline neutrino oscillation experiments, DUNE and T2HK, to look for new flavor-dependent neutrino interactions with electrons, protons, and neutrons that could affect the transitions between different flavors. We interpret their sensitivity in the context of long-range neutrino interactions, mediated by a new neutral boson lighter than $10^{-10}$ eV, and sourced by the vast amount of nearby and distant matter in the Earth, Moon, Sun, Milky Way, and beyond. For the first time, we explore the sensitivity of DUNE and T2HK to a wide variety of $U(1)^\prime$ symmetries, built from combinations of lepton and baryon numbers, each of which induces new interactions that affect oscillations differently. We find ample sensitivity: in all cases, DUNE and T2HK may constrain the existence of the new interaction even if it is supremely feeble, may discover it, and, in some cases, may identify the symmetry responsible for it. △ Less

Submitted 17 September, 2024; v1 submitted 3 April, 2024; originally announced April 2024.

Comments: 52 pages, 20 figures, 6 tables, and 5 appendices. Sensitivity results in the form of digitized files can be found at https://github.com/pragyanprasu/LRI-LBL-2024. This version has the same content as the published article in the Journal of High Energy Physics

Report number: IP/BBSR/2024-01

Constraints on the Blazar-Boosted Dark Matter from the CDEX-10 Experiment

Authors: R. Xu, L. T. Yang, Q. Yue, K. J. Kang, Y. J. Li, H. P. An, Greeshma C., J. P. Chang, Y. H. Chen, J. P. Cheng, W. H. Dai, Z. Deng, C. H. Fang, X. P. Geng, H. Gong, Q. J. Guo, T. Guo, X. Y. Guo, L. He, S. M. He, J. W. Hu, H. X. Huang, T. C. Huang, L. Jiang, S. Karmakar , et al. (59 additional authors not shown)

Abstract: We report new constraints on light dark matter (DM) boosted by blazars using the 205.4 kg day data from the CDEX-10 experiment located at the China Jinping Underground Laboratory. Two representative blazars, TXS 0506+56 and BL Lacertae are studied. The results derived from TXS 0506+56 exclude DM-nucleon elastic scattering cross sections from $4.6\times 10^{-33}\ \rm cm^2$ to… ▽ More We report new constraints on light dark matter (DM) boosted by blazars using the 205.4 kg day data from the CDEX-10 experiment located at the China Jinping Underground Laboratory. Two representative blazars, TXS 0506+56 and BL Lacertae are studied. The results derived from TXS 0506+56 exclude DM-nucleon elastic scattering cross sections from $4.6\times 10^{-33}\ \rm cm^2$ to $1\times10^{-26}\ \rm cm^2$ for DM masses between 10 keV and 1 GeV, and the results derived from BL Lacertae exclude DM-nucleon elastic scattering cross sections from $2.4\times 10^{-34}\ \rm cm^2$ to $1\times10^{-26}\ \rm cm^2$ for the same range of DM masses. The constraints correspond to the best sensitivities among solid-state detector experiments in the sub-MeV mass range. △ Less

Submitted 29 March, 2024; originally announced March 2024.

Comments: 7 pages, 4 figures

Probing Dark Matter Particles from Evaporating Primordial Black Holes via Electron Scattering in the CDEX-10 Experiment

Authors: Z. H. Zhang, L. T. Yang, Q. Yue, K. J. Kang, Y. J. Li, H. P. An, Greeshma C., J. P. Chang, Y. H. Chen, J. P. Cheng, W. H. Dai, Z. Deng, C. H. Fang, X. P. Geng, H. Gong, Q. J. Guo, T. Guo, X. Y. Guo, L. He, S. M. He, J. W. Hu, H. X. Huang, T. C. Huang, L. Jiang, S. Karmakar , et al. (59 additional authors not shown)

Abstract: Dark matter (DM) is a major constituent of the Universe. However, no definite evidence of DM particles (denoted as ``$χ$") has been found in DM direct detection (DD) experiments to date. There is a novel concept of detecting $χ$ from evaporating primordial black holes (PBHs). We search for $χ$ emitted from PBHs by investigating their interaction with target electrons. The examined PBH masses range… ▽ More Dark matter (DM) is a major constituent of the Universe. However, no definite evidence of DM particles (denoted as ``$χ$") has been found in DM direct detection (DD) experiments to date. There is a novel concept of detecting $χ$ from evaporating primordial black holes (PBHs). We search for $χ$ emitted from PBHs by investigating their interaction with target electrons. The examined PBH masses range from 1$\times$10$^{15}$ to 7$\times$10$^{16}$ g under the current limits of PBH abundance $f_{PBH}$. Using 205.4 kg$\cdot$day data obtained from the CDEX-10 experiment conducted in the China Jinping Underground Laboratory, we exclude the $χ$--electron ($χ$--$e$) elastic-scattering cross section $σ_{χe} \sim 5\times10^{-29}$ cm$^2$ for $χ$ with a mass $m_χ\lesssim$ 0.1 keV from our results. With the higher radiation background but lower energy threshold (160 eV), CDEX-10 fill a part of the gap in the previous work. If ($m_χ$, $σ_{χe}$) can be determined in the future, DD experiments are expected to impose strong constraints on $f_{PBH}$ for large $M_{PBH}$s. △ Less

Submitted 22 September, 2024; v1 submitted 29 March, 2024; originally announced March 2024.

Comments: 9 pages, 6 figures, 3 tables. Version updated to match SCPMA version

Journal ref: Sci. China Phys. Mech. Astron. 67, 101011 (2024)

Anomalous kaon correlations measured in Pb-Pb collisions at the LHC as evidence for the melting and refreezing of the QCD vacuum

Authors: Joseph Kapusta, Scott Pratt, Mayank Singh

Abstract: Measurements of the dynamical correlations between neutral and charged kaons in central Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV by the ALICE Collaboration display anomalous behavior relative to conventional heavy-ion collision simulators. We consider other conventional statistical models, none of which can reproduce the magnitude and centrality dependence of the correlations. The data can b… ▽ More Measurements of the dynamical correlations between neutral and charged kaons in central Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV by the ALICE Collaboration display anomalous behavior relative to conventional heavy-ion collision simulators. We consider other conventional statistical models, none of which can reproduce the magnitude and centrality dependence of the correlations. The data can be reproduced by coherent emission from domains which grow in number and volume with increasing centrality. We study the dynamical evolution of the strange quark condensate and show that the energy released during the expansion and cooling of the system may be sufficient to explain the anomaly. △ Less

Submitted 17 March, 2024; originally announced March 2024.

Comments: 4 pages, 4 figures, Quark Matter 2023 Proceedings