Tue·Dec 2, 2025Tuesday·December 2, 2025

1. 01*

   Widen the Resonance at Ultra-High Energies: Novel Probes of Neutrino Self-interactions in the High-Mass Regime

   Pedro A. N. Machado🇺🇸 · Isaac R. Wang🇺🇸 · Xun-Jie Xu🇨🇳 · Bei Zhou🇺🇸

   Neutrino self-interaction beyond the Standard Model is well motivated by the nonzero masses of neutrinos, which are the only known particles guaranteed to have new physics. Cosmic messengers, especially neutrinos, play a central role in probing new physics, as they provide experimental conditions far beyond the reach of laboratories and serve as the link between laboratory fundamental-physics discoveries and their roles in the Universe, where many new physics motivations originate. In this work, we propose a novel probe of neutrino self-interactions through ultra-high-energy neutrinos scattering off the cosmic neutrino background when the lightest neutrino species remains relativistic today. This allows us to ``Widen the Resonance'' of such scattering. Meanwhile, we also provide a semi-analytic framework for cosmogenic UHE neutrino production, avoiding computationally intensive simulations and yielding results precise enough for BSM studies. The widened resonance enables future ultrahigh-energy neutrino telescopes, in particular GRAND, to probe mediator masses from MeV to GeV, reaching couplings down to $g\sim 10^{-3}$ -- up to two orders of magnitude beyond current bounds. Our results enhance the discovery potential of $\nu$SI in the high-mass regime, potentially offering crucial insights into the connections between the neutrino sector and dark sector.

   hep-phastro-ph.COastro-ph.HEhep-exJCAP(2026)·4 citations
2. 02*

   Searching for Ultralight Dark Matter with MOLeQuTE: a Massive Optically Levitated Quantum Tabletop Experiment

   Louis Hamaide🇮🇹 · Hannah Banks🇬🇧 · Peter Barker🇬🇧 · Andrew A. Geraci🇺🇸

   Many well theoretically motivated models of ultralight dark matter are expected to give rise to feeble oscillatory forces on macroscopic objects. Optically trapped sensors have high force sensitivities but have remained relatively unexplored in this context. In this work we propose a new, tunable, optically trapped sensor specifically designed to detect such forces. Our design features a high-mass ($\sim$ mg) plate whose high aspect ratio allows its weight to be supported by a vertical beam without excessive heating. We present the first systematic analysis and optimisation of quantum noises in optically trapped systems and show that our setup has the potential to operate at the standard quantum limit with current off-the-shelf technologies. We demonstrate that our sensor could offer unique access to large regions of uncharted parameter space of vector B-L dark matter, with projected sensitivities that could advance existing limits by several orders of magnitude over a broad range of frequencies.

   hep-phhep-exquant-ph3 citations
3. 03*

   Enhancing the sensitivity to neutrino oscillation parameters using synergy between T2K, NO$\nu$A and JUNO

   Srubabati Goswami🇮🇳 · Aman Gupta🇮🇳 · Ushak Rahaman🇨🇦 · Sushant K. Raut🇮🇳

   We study the impact of combining the present NO$\nu$A and T2K data with simulated data from the JUNO experiment on the determination of the leptonic CP phase and the neutrino mass hierarchy. The current NO$\nu$A data exhibit a hierarchy--${\delta }_{\mathrm{CP}}$ degeneracy, admitting both normal hierarchy (NH) with ${\delta }_{\mathrm{CP}}\in [0,180^{\circ }]$, and inverted hierarchy (IH) with ${\delta }_{\mathrm{CP}}\in [180^{\circ },360^{\circ }]$ solutions at comparable significance, while T2K prefers ${\delta }_{\mathrm{CP}}\simeq 270^{\circ }$ for both hierarchies, leading to a $2\sigma$ tension between the two experiments for normal hierarchy. Using detailed GLoBES simulations, we show that future JUNO data with excellent hierarchy sensitivity, can lift the hierarchy--${\delta }_{\mathrm{CP}}$ degeneracy in NO$\nu$A and strengthen the hierarchy reach of T2K in spite of having no ${\delta }_{\mathrm{CP}}$ sensitivity. Allowing the hierarchy to be a free parameter in the fit, if the true ordering is IH, JUNO aligns the NO$\nu$A and T2K allowed regions and resolves their present tension; if NH is true, the tension continues to persist. We also show that JUNO's precise measurement of $|{\Delta }_{31}|$ leads to improved constraints on ${\sin }^2{\theta }_{23}$ and ${\delta }_{\mathrm{CP}}$ for normal mass hierarchy in NO$\nu$A even though JUNO itself is insensitive to these parameters. Finally, updated solar parameter measurements from JUNO's first data release further enhance the combined precision. Our results demonstrate that JUNO plays a crucial synergistic role in the global neutrino oscillation programme, enabling a more robust determination of the mass ordering and improving the sensitivity to the CP phase when combined with long-baseline data.

   hep-phhep-exhep-thJHEP(2026)·12 citations
4. 04*

   Why Is Attention Sparse In Particle Transformer?

   Timothy Legge🇺🇸 · Aaron Wang🇺🇸 · Jacob Ortiz🇺🇸 · Victor Limouzi🇺🇸 · Zihan Zhao🇺🇸 · Abhijith Gandrakota🇺🇸 · Elham E. Khoda🇺🇸 · Jennifer Ngadiuba🇺🇸 · Javier Duarte🇺🇸 · Richard Cavanaugh🇺🇸

   Transformer-based models have achieved state-of-the-art performance in jet tagging at the CERN Large Hadron Collider (LHC), with the Particle Transformer (ParT) representing a leading example of such models. A striking feature of ParT is its sparse, nearly binary, attention structure, raising questions about the origin of this behavior and whether it encodes physically meaningful correlations. In this work, we investigate the source of ParT's sparse attention by comparing models trained on multiple benchmark datasets and examine the relative contributions of the attention term and the physics-inspired interaction matrix before softmax. We find that binary sparsity arises primarily from the attention mechanism itself, with the interaction matrix playing a secondary role. Moreove, we show that ParT is able to identify key jet substructure elements, such as leptons in semileptonic top decays, even without explicit particle identification inputs. These results provide new insight into the interpretability of transformer-based jet taggers and clarify the conditions under which sparse attention patterns emerge in ParT.

   hep-phhep-exphysics.data-an3 citations
5. 05*

   Gravitational form factors of the baryon octet in holographic QCD

   Zhibo Liu🇯🇵 · Hiroaki Nakajima🇨🇳 · Hiroaki Abuki🇯🇵 · Akira Watanabe🇯🇵

   The gravitational form factors (GFFs) of the baryon octet, including hyperons, are investigated in a bottom-up holographic QCD model that explicitly incorporates the SU(3) flavor symmetry breaking through the strange quark mass. We fit the model parameters to reproduce the empirical masses of the baryon octet and examine the dependence of GFFs on the probe momentum. Our numerical results show distinct differences in the GFFs across the baryon octet. The computed GFFs are found to be in reasonable agreement with available lattice QCD results for the non-strange/nucleon sector. We also calculate the gravitational radii of the baryon octet and find that they decrease with increasing strangeness, indicating that heavier hyperons are more compact.

   hep-phnucl-thJHEP(2026)·2 citations
6. 06*

   Strong Decays of the Light Exotic $0^{+-}$ and $2^{+-}$ Hybrid Mesons

   Christian Farina🇺🇸 · Eric S. Swanson🇺🇸

   A model of hybrid meson structure based on the QCD Hamiltonian in Coulomb gauge and the use of a single constituent quasigluon is applied compute hadronic decays of mesons with exotic quantum numbers, $0^{+-}$ and $2^{+-}$. These correspond to hybrid mesons in which the gluon couples to a $q\bar{q}$ pair in an $P$-wave and can therefore be identified as orbital excitations of the exotic $1^{-+}$ state. Interestingly, we find $0^{+-}$ states to be narrow, contrary to what was found by previous calculations. This is primarily due to the suppression of the decay mode $0^{+-}\to 2^1{S}_0+1^1{S}_0$, which is unique to our model. The $2^{+-}$ states are found to be narrow, as expected.

   hep-phEPJC(2026)·0 citations
7. 07*

   QCD corrections to charged-current decays with Heavy Sterile Neutrinos in initial or final state and their impact on $\tau$ decays

   Tim Kretz🇩🇪 · Ulrich Nierste🇩🇪

   Searches for a Heavy Sterile Neutrino $N$ profit from precise predictions of inclusive decay rates, entering predictions for branching fractions and lifetime. Once decay channels into semi-hadronic final states are open, a reliable calculation of inclusive decay rates is only possible if $N$ is heavy enough to permit a perturbative calculation. We adopt the scenario in which $N$ only interacts with SM particles through $N$-${\nu }_{\ell }$ mixing, where $\ell =e,\mu ,\tau$. Using literature results for $W$ boson correlators calculated to $\mathcal{O}({\alpha }_s^4)$, we study the quality of the perturbation series for $N\to \ell +\text{mbox}hadrons$ to determine mass ranges for which inclusive decay widths can be predicted robustly. We present novel analytic results for the decay rate $N\to \tau +\text{mbox}hadrons$ in terms of $m_{\tau }/m_N$. Our expressions equally apply to $\tau \to N+\text{mbox}hadrons$, perturbatively calculable for $m_N\lesssim 600$MeV. Applying our result to the $\tau$ lifetime, we determine the allowed parameter space for the $N$-${\nu }_{\tau }$ mixing angle $\theta$ and $m_N$. We find $|\sin \theta |\le 0.2$ for $m_N=600$MeV and weaker bounds for a lighter $N$. For $m_N\ge m_{\tau }$ we find constraints from the dependence of $\tau$ decay rates on $\cos \theta$. Combining $\tau \to {\pi }^{-}{\nu }_{\tau }$ and $\tau \to K^{-}{\nu }_{\tau }$ data gives $|\sin \theta |=(9.1_{-7.8}^{+3.7})\cdot 10^{-2}$ while $N$-${\nu }_{\tau }$ mixing does not improve the agreement between theory and data for $\tau \to \ell {\bar{\nu }}_{\ell }{\nu }_{\tau }$. We find current data for the decay rate $\Gamma (\tau \to \ell +\text{mbox}nothing)$ about 1$\sigma$ above the SM prediction for $\Gamma (\tau \to \ell {\bar{\nu }}_{\ell }{\nu }_{\tau })$, which leads to useful constraints on $\Gamma (\tau \to \ell X_{\mathrm{dark}})$ with dark-sector particles $X_{\mathrm{dark}}$ and might stimulate additional experimental effort on $\tau \to \ell +\text{mbox}nothing$.

   hep-phJHEP(2026)·2 citations
8. 08*

   Dispersive analysis of the $J/\psi \to {\pi }^0{\gamma }^{\ast }$ transition form factor with $\rho$-$\omega$ mixing effects

   Xiong-Hui Cao🇨🇳 · Feng-Kun Guo🇨🇳 · Christoph Hanhart🇩🇪 · Bastian Kubis🇩🇪

   Motivated by the discrepancies noted recently between the theoretical predictions of the electromagnetic $J/\psi \to {\pi }^0{\gamma }^{\ast }$ transition form factor and the BESIII data, we reanalyze this transition form factor using the dispersive Khuri-Treiman equations, with final-state interactions in both the direct channel and the crossed channels properly considered. This improved framework incorporates $\rho$-$\omega$ mixing effects. The effect of four-pion states is evaluated through a dispersively improved vector-meson-dominance model. From this information, we propose a two-parameter fit that provides an excellent description of the BESIII data over the broad energy range from 0 to 2.8GeV. We demonstrate that the $\rho {\pi }^0$ decay mode of the $J/\psi$ is dominated by strong interaction, while the $\omega {\pi }^0$ mode is dominated by one-photon exchange. From this, we extract the relative phase between the strong and the one-virtual-photon (electromagnetic) modes in hadronic decays of $J/\psi$ as $(62\pm 21{)}^{\circ }$. This could provide useful information in understanding the long-standing $\rho \pi$ puzzle in $J/\psi$ decays.

   hep-phhep-exPRD(2026)·5 citations
9. 09*

   Exploring Background Contributions in $H\to Z\gamma$ Decay

   Aliaksei Kachanovich🇧🇪

   The rare decay $H\to Z\gamma$ has been investigated by both the ATLAS and CMS Collaborations, with each reporting an excess in Run~2 in 2023 characterized by $\mu =2.2\pm 0.7$. This anomaly was initially attributed to possible modifications of the $HZ\gamma$ vertex. However, because the $H\to Z\gamma$ signal is reconstructed via the $H\to \ell \ell \gamma$ channel, background effects -- particularly those from processes that mimic the same final state -- may have been underestimated. In this work, we re-examine these backgrounds in detail and propose that the observed excess could be explained by an additional BSM-induced contribution. We present both an effective field theory framework and a UV-complete model that provide the necessary rates and a consistent interpretation of the data. The proposed model reproduces the newest ATLAS result, $\mu =1.3_{-0.5}^{+0.6}$, obtained using a narrower dilepton invariant-mass window.

   hep-phPoS(2026)·0 citations
10. 10*

    Closepacking effects on strangeness and baryon production at the LHC

    Javira Altmann🇦🇺 · Lorenzo Bernardinis🇮🇹 · Peter Skands🇦🇺 · Valentina Zaccolo🇮🇹

    Data from the LHC show a rise in strange-hadron production with charged-particle multiplicity in pp collisions. The Monte-Carlo event generator PYTHIA, using its default Monash tune, instead predicts constant strangeness. We investigate a mechanism invoked during hadronization called string closepacking, where overlapping strings generate a background field, here assumed to be predominantly aligned with the beam axis. This increases the effective string tension, reducing strangeness suppression and thus enhancing strangeness production. We tune this model to LHC data and contrast it with several alternatives. We comment specifically on the challenge of simultaneously describing the non-strange p/pi ratio, and introduce a mechanism which may act to suppress it. Many of the salient particle-production ratios can be qualitatively described by this model, although the XiC/D ratio and the shape of pT spectra remain challenging to account for.

    hep-phhep-exJHEP(2026)·6 citations
11. 11*

    Probing a minimal dark gauge sector via microlensing of compact dark objects

    Juan Barranco🇲🇽 · Argelia Bernal🇲🇽 · Víctor Jaramillo🇨🇳 · Darío Núñez🇲🇽 · Milton Ruiz🇪🇸

    We introduce a minimal Dark Standard Model (DSM) consisting of a single spin-0 particle with dark $U(1)$ gauge symmetry, and completely decoupled from the visible sector. Characterized only by the scalar mass $\mu$ and the dark charge $q$, this framework naturally gives rise to a rich phenomenology, including stable solitonic configurations that behave as dark "mini-MACHOs". We numerically build and evolve these gauged scalar-field solitons, derive their mass-radius relations, and identify a critical charge beyond which no gravitationally bound configurations exist. By combining these results with microlensing surveys that exclude compact objects heavier than the asteroid-mass scale ($M\lesssim 10^{-11}{M}_{\odot }$), we obtain the constraint $\mu \gtrsim 10\mathrm{eV}$ for viable configurations, depending on $q$. Our results represent a step forward in showing that purely gravitational observations can constrain the internal parameters of a dark gauge sector, and provide a framework for exploring broader DSM scenarios through future probes such as gravitational wave detections.

    hep-phastro-ph.COgr-qcJCAP(2026)·0 citations
12. 12*

    The Gauge Principle and Foundations of The Standard Model: A Pedagogical Introduction Through QED

    Taha Anwar🇵🇰

    The Standard Model of particle physics is built on the principle of local gauge symmetry. This work provides a pedagogical introduction for advanced undergraduates by using quantum electrodynamics (QED) as the simplest example of a gauge theory. Beginning with the Lagrangian formulation of classical mechanics, special relativity, and basic quantum mechanics, we develop classical field theory, reformulate electromagnetism in covariant form, introduce the Dirac equation for spin 1/2 particles, and finally arrive at the gauge principle. By showing how the requirement of local U(1) invariance leads naturally to the electromagnetic interaction, we illustrate the essential logic behind gauge theories and highlight the conceptual structure that underlies the Standard Model Lagrangian.

    hep-phphysics.ed-ph0 citations
13. 13*

    Quasi-Dirac fermion: A source of neutrino mass and dark matter

    Nguyen Thi Nguyet Nga · Nguyen Huy Thao🇻🇳 · Phung Van Dong🇻🇳

    Neutral vectorlike fermion as inspired by unified theories might become quasi-Dirac states at TeV due to a violation in lepton-like symmetry. It is shown that such quasi-Dirac fermions can properly achieve radiative neutrino mass generation and dark matter stability. Indeed, the small splitting of quasi-Dirac masses, i.e. $\Delta M/M\ll 1$, suitably suppresses neutrino mass to be small in order to allow dark matter annihilation and detection to be appropriate to experiment as well as charged lepton flavor violation limit.

    hep-phhep-th2 citations
14. 14*

    The QCD Scale Parameter from the Photon Structure Function

    Hun Jang🇰🇷 · Eun Bok🇰🇷 · Hyeunwoo Kim🇰🇷 · Byeongjun Yoon🇰🇷 · Sun Myong Kim🇰🇷

    Photon structure function has been a solid platform in testing strong interaction along with nucleon structure function. Strong Interaction has the property that it is perturbatively calculable at high energy but becomes non-perturbative at low energy. This nature makes QCD hard to handle theoretically in factorizing these two regions. The fundamental dimensional parameter, so called the QCD scale parameter, ${\Lambda }_{\overline{\text{MS}}}$, is one of key players to factorize two energy regions. In this work, we extract the QCD scale parameter from the photon structure function by separating the perturbative QCD and non-perturbative QCD. In the process we use the vector dominance model for the non-perturbative energy region of the photon structure function.

    hep-phJ.Korean Phys.Soc.(2026)·0 citations
15. 15*

    Exotic $T_{c\bar{s}0}^a(2900{)}^0$ and $T_{c\bar{s}0}^a(2900{)}^{++}$ states in Born-Oppenheimer approximation

    Halil Mutuk🇹🇷

    We employ Born-Oppenheimer approximation to the $T_{c\bar{s}0}^a(2900{)}^0$ and $T_{c\bar{s}0}^a(2900{)}^{++}$ states observed by the LHCb Collaboration and study mass spectrum and root-mean-square radius values. For this purpose, we use dynamical diquark model. We assume that strange quark is a heavy for the usage of Born-Oppenheimer approximation. Our results strongly indicate that the $T_{c\overline{s}0}^a(2900)$ states are best described as composed of axial-vector (spin-1) diquark pairs. Furthermore, the calculated root-mean-square radius, $⟨r^2{⟩}^{1/2}\approx 0.70-0.80$ fm, which is significantly less than 1 fm, provides compelling evidence that these are compact tetraquarks rather than loosely bound hadronic molecules.

    hep-phhep-exhep-latnucl-thPRD(2026)·4 citations
16. 16*

    Method to measure quarkonium wave function using $B_c$ decay

    Yukinari Sumino🇯🇵

    We propose a method that enables a direct experimental probe of the quarkonium wave function defined in potential nonrelativistic QCD (pNRQCD) using the three-body decay of the $B_c$ meson. We show that the momentum distribution of the spectator $c$-quark in the partonic decay is proportional to the absolute square of the momentum-space wave function of the $B_c$ state. It would provide, for the first time, an experimentally accessible probe of the quarkonium wave function.

    hep-phhep-ex0 citations
17. 17*

    Lorentz violation and momentum-space geometric phases

    Alan Kostelecky🇺🇸 · Ralf Lehnert🇺🇸 · Marco Schreck🇧🇷 · Babak Seradjeh🇺🇸

    Geometric phases can manifest when a relativistic quantum particle moves cyclically along a loop in parameter space. The phase can be affected by the presence of a background field and can be accompanied by nontrivial topological features. The appearance of adiabatic geometric phases in momentum space is demonstrated for a Lorentz-violating Weyl fermion, where the role of the background is played by the coefficients for Lorentz violation. As explicit examples, the Berry curvature and the first Chern number are derived for two cases with large Lorentz violation, one incorporating CPT violation and one preserving CPT symmetry. Some alternative topological invariants are also obtained. In certain scenarios with large Lorentz violation, the physical vacuum is associated with a topological phase.

    hep-phcond-mat.mes-hallPRD(2026)·6 citations
18. 18*

    Linear realization of SU(3) parity doublet model for octet baryons with bad diquark

    Bikai Gao🇯🇵 · Atsushi Hosaka🇯🇵

    We construct a linear $SU(3{)}_L\times SU(3{)}_R$ parity doublet model for octet baryons. Our model employs the $(3,\bar{3})+(\bar{3},3)$ and $(3,6)+(6,3)$ chiral representations while excluding the $(8,1)+(1,8)$ representation. Through systematic analysis, we demonstrate that the $(3,6)+(6,3)$ representation containing symmetric ``bad'' diquarks, despite being energetically disfavored, is essential for reproducing the correct baryon mass hierarchy, particularly the $\Sigma$$\Xi$ mass ordering. The model incorporates both spontaneous and explicit chiral symmetry breaking, with the latter implemented through bare quark mass terms that properly account for $SU(3)$ flavor breaking effects. Our numerical analysis successfully reproduces the ground-state octet baryon masses and predicts the spectrum of excited states up to 2.5 GeV. For the experimentally challenging $\Xi$ sector, we provide specific predictions for spin-parity assignments: identifying $\Xi (1950)$ as the first positive-parity excitation. The analysis reveals that ground states are dominated by the $(3,\bar{3})+(\bar{3},3)$ representation, consistent with the preference for ``good'' diquark configurations, while the $(3,6)+(6,3)$ contribution remains crucial for the mass spectrum.

    hep-phhep-thnucl-thPRD(2026)·4 citations
19. 19*

    Analysis of $H\to J/\psi +\gamma$ up to Next-to-Next-to-Leading Order QCD Corrections

    Wen-Yuan Li🇨🇳 · Ting Sun🇨🇳 · Sheng-Quan Wang🇨🇳 · Jian-Ming Shen🇨🇳 · Hua Zhou🇨🇳 · Xing-Gang Wu🇨🇳 · Leonardo Di Giustino🇮🇹

    The rare exclusive decay of the Higgs boson $H\to J/\psi +\gamma$ is an important channel for measuring the Yukawa coupling of the charm quark. In this article, we analyze the process by employing the Principle of Maximum Conformality (PMC) up to the next-to-next-to-leading order (NNLO) in QCD. Conventional scale setting leads to theoretical predictions affected by errors dominated by renormalization scale uncertainty. The PMC provides a systematic method to eliminate this renormalization scale uncertainty by resumming non-conformal $\beta$ contributions into the QCD running coupling via renormalization group equation (RGE). We obtain a PMC scale result of $Q_{\star }=3.29\text{GeV}$, which reflects the low virtuality of the underlying QCD dynamics for the $H\to J/\psi +\gamma$ process. In fact, this is an order of magnitude smaller than the guessed scale using the conventional method, i.e., ${\mu }_r=m_H/2$. By removing non-conformal $\{{\beta }_i\}$-terms from the perturbative QCD (pQCD) series, the PMC eliminates renormalization scale uncertainty. Comparing results, we find that the PMC NLO QCD correction term is significantly enhanced, while the PMC NNLO QCD correction is suppressed. This indicates improved convergence of the pQCD series up to NNLO. Finally, we determine the decay width $\Gamma (H\to J/\psi +\gamma )=14.183_{-0.347}^{+0.249}\pm 0.022$ eV, where the first error arises from the factorization scale ${\mu }_{\Lambda }\in [1,2]\text{GeV}$, and the second error from estimating unknown higher-order terms using the Pade approximant approach. The corresponding branching fraction is $\mathcal{B}(H\to J/\psi +\gamma )=3.485_{-0.161}^{+0.152}\times 10^{-6}$.

    hep-phChinese Physics C.50.103108 (2026)·0 citations
20. 20*

    Effect of super-Gaussian pulse shape on pair production in chirped electric field with spatial inhomogeneity

    Xiao-Ting Xu🇨🇳 · Le-Le Chen🇨🇳 · Rong-an Tang🇨🇳 · Xue-Ren Hong🇨🇳 · Lie-Juan Li🇨🇳 · Bai-Song Xie🇨🇳

    Pair production in spatially inhomogeneous chirped electric fields with super-Gaussian pulse shape is investigated using the Dirac-Heisenberg-Wigner formalism, and the effect of super-Gaussian pulse shapes on the reduced momentum spectrum and the reduced total yield of created particles is mainly concerned. It is found that with the variation of the super-Gaussian envelope exponent, the momentum spectrum exhibits the more pronounced oscillations, shifting and broadening. The total yield of created particles increases monotonically with the increase of the super-Gaussian envelope exponent in the high-frequency fields with small chirp and low-frequency fields with any chirp. Meanwhile, the total yield of created particles under the super-Gaussian pulse electric fields is approximately twice that produced with the usual Gaussian pulse envelope. These results can provide theoretical guidance for optimizing the form of external field to enhance the vacuum pair production rate.

    hep-phPRD(2026)·1 citation
21. 21*

    A Coupled Source Description of Pseudorapidity Distributions from RHIC to LHC: Emergent $1/{\mu }_B$ Scaling and Limiting Fragmentation

    Neeraj · Md. Kaosar Ali Mondal · Amal Sarkar🇮🇳

    One of the most remarkable observations in heavy-ion collisions is the systematic regularity exhibited by pseudorapidity distributions of charged particles across collision energies. While single-source models fail at higher energies and independent multi-source approaches do not reproduce the central dip observed at LHC energies, a unified description across the full RHIC-LHC energy range remains elusive. These distributions from Au+Au collisions at RHIC ($\sqrt{s_{NN}}$ = 19.6--200 GeV) and Pb+Pb collisions at LHC ($\sqrt{s_{NN}}$ = 2.76--5.36 TeV) are analyzed using a novel parametrization based on coupled Gaussian sources where the interaction strength is quantified by parameter $\lambda$. This coupled two-source model captures the interaction between forward and backward sources through the medium formed in the collision. Remarkably, $\lambda$ exhibits empirical scaling behavior resembling $1/{\mu }_B$, suggesting sensitivity to baryon stopping and the strongly-interacting medium. All fitting parameters follow systematic energy trends, with the peak-to-peak distance and chemical freeze-out temperature exhibiting identical exponential saturation patterns, indicating that geometric expansion and thermal evolution share a common underlying dynamics governed by QCD phase structure. Furthermore, the approach naturally preserves limiting fragmentation behavior across all energies, in contrast to independent source models that suggest its violation at LHC energies. Although the theoretical basis requires further investigation, these empirical correlations successfully unify charged particle production across nearly two orders of magnitude in collision energy, revealing fundamental connections to underlying collision dynamics.

    hep-ph0 citations
22. 22*

    Resonant Annihilation of WIMP Dark Matter for Halo Gamma Ray Signal

    Hitoshi Murayama🇺🇸

    We propose a resonant annihilation as a way to reconcile the WIMP annihilation cross sections in a recently reported gamma ray signal from the Milky Way halo with that for the freeze-out and the upper limit from dwarf galaxies. We perform a simple model-independent analysis based on this hypothesis and determine the required parameters. We also present a simple particle-physics model that can accommodate them.

    hep-phastro-ph.HE9 citations
23. 23*

    Standard Model and SMEFT Higgs theory overview

    Ramona Gröber🇮🇹

    After more than a decade from its discovery, the Higgs boson remains at the centre of the particle physics programme. While its couplings to vector bosons and third-generation fermions have been measured with impressive precision, the structure of the Higgs potential, the self-couplings, and the interactions with first- and second-generation fermions are still poorly constrained. This contribution summarises recent theoretical progress in precision predictions in Higgs physics, the interpretation of these results in Effective Field Theories (EFTs), and the current and future prospects to probe light Yukawa couplings at the LHC and beyond.

    hep-phPoS(2026)·2 citations
24. 24*

    Decoding the structure near the ${\pi }^{+}{\pi }^{-}$ mass threshold in $\psi (3686)\to J/\psi {\pi }^{+}{\pi }^{-}$ decays

    Yun-Hua Chen🇨🇳 · Xiang-Kun Dong🇩🇪 · Feng-Kun Guo🇨🇳 · Christoph Hanhart🇩🇪 · Bastian Kubis🇩🇪

    In light of recent high-precision data taken by the BESIII Collaboration, we reconsider the dipion transition $\psi (3686)\to J/\psi {\pi }^{+}{\pi }^{-}$. The strong pion-pion final-state interactions are taken into account model-independently by using dispersion theory. We find that we can reproduce the substructure near the ${\pi }^{+}{\pi }^{-}$ threshold observed experimentally without introducing an extra resonance state. While a helicity-flip amplitude plays an important role for the formation of the dip in the invariant-mass distribution, the virtual exchange of the charmoniumlike exotic $Z_c(3900)$ state improves the fit quality only slightly.

    hep-phhep-exnucl-thPRD(2026)·3 citations
25. 25*

    The effect of Coulomb interactions on relic neutrino detection via beta decaying impurities in (semi)metals

    Karel van der Marck🇳🇱 · Vadim Cheianov🇳🇱

    Measuring the electron neutrino mass is a long-standing objective and requires a high energy resolution of certain $\beta$-decay experiments, as well as a visible cosmic neutrino background (C$\nu$B) spectrum. Many quantum mechanical and chemical effects could potentially impair the required resolution/visibility, e.g., the Coulomb interactions between the electrons in the $\beta$-decaying impurity and in the solid-state environment. We analyze the effect when hybridization is suppressed completely using a dielectric spacer, and also when hybridization is present up to the lowest nontrivial order in perturbation theory.

    hep-phcond-mat.mes-hallcond-mat.othercond-mat.str-el+1SciPost Phys.(2026)·0 citations
26. 26*

    Data-Driven Refinement of an Analytical Holographic Model for the QCD Phase Transition

    Xun Chen🇨🇳 · Floriana Giannuzzi🇮🇹 · Stefano Nicotri🇮🇹

    Using (2+1)-flavor lattice QCD data, we refine the parameters of an analytical holographic model via gradient descent optimization to precisely locate the critical endpoint in the $T-\mu$ plane. Specifically, we calibrate the model using input data for the speed of sound at ${\mu }_B=0$, the second-order baryon number susceptibility ${\chi }_2^B$, and the baryon number density at ${\mu }_B/T=1$. With these parameters fixed, we calculate pressure and energy density versus temperature at small chemical potentials and compare the results with lattice QCD data using Taylor expansion techniques. This comparison validates the robustness of our model upon extension to finite chemical potentials, as the results show broad consistency with lattice QCD data in this regime. Finally, we employ the calibrated model to determine the coordinates of the critical endpoint in the $T-{\mu }_B$ plane, finding it located at $({\mu }_B=0.678\mathrm{GeV},\mathrm{T}=0.110\mathrm{GeV})$

    hep-phPRD(2026)·5 citations
27. 27*

    PrecisionSM: an annotated database for low-energy $e^{+}{e}^{-}$ hadronic cross sections

    Lorenzo Cotrozzi🇬🇧 · Anna Driutti🇮🇹 · Fedor Ignatov🇬🇧 · Alberto Lusiani🇮🇹 · Graziano Venanzoni🇬🇧

    PrecisionSM is an annotated database that compiles the available data on low-energy cross sections of electron-positron collisions into hadronic channels. This database organizes and collects data samples from $e^{+}{e}^{-}$ experiments, which are used as input for the data-driven theoretical evaluation of the muon anomalous magnetic moment, $a_{\mu }$, serving as a precise test of the Standard Model when compared to the experimental measurements of $a_{\mu }$. The database is accessible through a custom website (https://precision-sm.github.io) which contains details about the data samples, such as the treatment of radiative corrections, as well as links to papers on INSPIRE-HEP and to tables on HEPData. The PrecisionSM database was developed within a Joint Research Initiative in the group application of the European hadron physics community, STRONG2020, and is now incorporated into the RadioMonteCarLow2 Working Group (RMCL2 WG) activities, which have the more general goal of improving the theoretical description of scattering processes at $e^{+}{e}^{-}$ colliders. The results of Phase I of the new RMCL2 WG have been published in Aliberti et al, arXiv:hep-ph/2410.22882. In this proceeding, we will report on the status of the PrecisionSM database, which currently contains a list of the dominant $2\pi$ channel as well as $3\pi$ and ${\pi }^0\gamma$, and on the ongoing work for the other channels and for responsive plots.

    hep-phhep-exPoS(2026)·0 citations
28. 28*

    Probing neutrino-night-quark effective scalar interactions from neutrino masses

    Feng-Zhi Chen🇨🇳 · Junlin Huang🇨🇳 · Fanrong Xu🇨🇳

    In this work, we use neutrino masses as a probe of the neutrino-light-quark effective scalar interactions. It is found that neutrinos can acquire masses not only from the usual light quark loop corrections but also from the light quark condensates. The latter contribution has been overlooked in the literature. We show that both contributions are comparable for operators involving $u$ and $d$ quarks, while quark loop corrections dominate for operators involving the $s$ quark. Using the low-energy effective field theory extended with light right-handed neutrinos and matching to chiral perturbation theory, we systematically analyze these contributions, deriving constraints on the corresponding Wilson coefficients from neutrino mass bounds, coherent elastic neutrino-nucleus scattering, and light pseudoscalar meson invisible decays. Our analysis shows that electron neutrino mass measurements provide the most stringent constraints on these scalar couplings, significantly improving upon limits from other observables. The results highlight the importance of including both perturbative and nonperturbative contributions in complete phenomenological analyses of neutrino mass generation mechanisms.

    hep-phPRD(2026)·0 citations
29. 29*

    Towards Precision Gluon Densities at Small $x$: From Resummation to Collider Observables

    Francesco Giovanni Celiberto🇪🇸 · Marco Bonvini🇮🇹

    Accurate gluon densities at small $x$ are essential for reducing theoretical uncertainties in collider predictions, yet remain one of the least constrained ingredients in global analyses. We report recent advances in the resummation of small-$x$ logarithms in the gluon sector, focusing on collinear distributions and their interplay with transverse-momentum-dependent formulations. Particular attention is paid to the impact of gluon-proton spin correlations and to the emergence of unintegrated gluon densities derived from resummed dynamics. These developments aim to fill the current precision gap in the small-$x$ region and enable robust applications to LHC and future-collider observables.

    hep-phhep-exhep-thPoS(2026)·6 citations
30. 30*

    Emergent Grand Unified Structure in a 4 x 4 Nilpotent Matrix Algebra

    M. Adeel Ajaib🇺🇸

    We show that nilpotent matrices that yield the Schrodinger equation from its first order form encode the fingerprints of grand unified theories. We perform a rigorous search for all such nilpotent matrices and find that the resulting matrices naturally organize into suggestive group theoretic structures without any other a priori assumptions. The antisymmetric sector consists of three groups of sixteen matrices, each of which further splits as 16 = 12 + 4 and exhibits unique characteristics in the step potential scattering problem. The symmetric zero-diagonal sector also forms three families, mirroring the quark-lepton decomposition of the Pati-Salam model. These results may help answer why there are three families of fermions and also demonstrate that the 4 x 4 matrix algebra is a compact, nontrivial shadow of the SO(10) embedding, with fermion-like and gauge-like subspaces.

    hep-ph0 citations
31. 31*

    Modified Entanglement Patterns in Two-Flavor Neutrinos from Quantum-Gravity Interactions

    Bipin Singh Koranga🇮🇳 · Parnav Kumar🇮🇳 · Baktiar Wasir Farooq🇮🇳

    In this work, we investigate the influence of quantum gravity induced corrections on the entanglement entropy associated with two flavor neutrino oscillations in vacuum. Using the Von Neumann entropy as a measure of quantum correlations, we analyze how Planck scale suppressed modification implemented through quantum gravity motivated changes in the neutrino dispersion relation affect the evolution of entanglement during successive oscillation cycles. By performing a statistical study over a range of oscillation lengths and neutrino energies, we identify characteristic deviations in the entropy profile arising from quantum gravity effects. Our results suggest that entanglement entropy provides a sensitive probe of small quantum gravity induced departures from standard neutrino oscillation dynamics, highlighting its potential role in testing Planck scale physics within neutrino phenomenology.

    hep-phNPB(2026)·3 citations
32. 32*

    QCD in Language Models: What do they really know about QCD?

    Antonin Sulc🇺🇸 · Patrick L.S. Connor🇨🇭

    This study presents an analysis of modern open-source large language models (LLMs) -- including Llama, Qwen, and Gemma -- to evaluate their encoded knowledge of Quantum Chromodynamics (QCD). Through reverse engineering of these models' representations, we uncover the naturally idiosyncratic patterns in how foundational QCD concepts are embedded within their parameter spaces. Our methodology combines targeted probing techniques and knowledge extraction protocols to assess the models' understanding of critical QCD principles like color confinement, asymptotic freedom, and the running coupling constant. This work provides a tool for utilizing LLMs as an assistant in physics research, while also highlighting current limitations in their representation of advanced quantum field theory concepts that future model development should address.

    hep-phphysics.data-anPoS(2026)·1 citation
33. 33*

    Unitarizing non-relativistic scattering

    Marcos M. Flores🇫🇷 · Kalliopi Petraki🇫🇷

    Unitarity imposes coupled constraints on elastic and inelastic amplitudes. Satisfying them requires resummation of the self-energy contributions from both elastic and inelastic channels. Inelastic channels generate anti-Hermitian contributions that can be consistently deduced from the unitarity relation underlying the optical theorem, leading to non-local separable potentials and a compact, unique and complete unitarization scheme in the non-relativistic regime. We present two alternative derivations of the anti-Hermitian kernel, from the continuity equation combined with LSZ reduction, and by integrating out inelastic channels. We further extend the unitarization framework to treat non-analytic and non-convergent behavior of inelastic amplitudes in the complex momentum plane and to incorporate bound states. For non-convergent amplitudes, we demonstrate two renormalization procedures in which anti-Hermitian separable potentials necessarily induce Hermitian separable counterterms, yielding finite cross-sections consistent with unitarity. These results provide a general tool for non-relativistic scattering, with clear applications to dark-matter phenomenology.

    hep-phhep-thJHEP(2026)·5 citations
34. 34*

    Do neutrinos dream in 5D? Towards a comprehensive extra-dimensional neutrino phenomenology

    Arturo de Giorgi🇬🇧 · Dhruv Pasari🇬🇧 · Jessica Turner🇬🇧

    This paper provides a comprehensive overview of neutrino masses and mixing in Large Extra Dimension scenarios, focusing on the phenomenological impact of a five-dimensional (5D) bulk fermion. In a flat extra dimension compactified on an $S^1/{\mathbb{Z}}_2$ orbifold, this fermion manifests as a Kaluza-Klein tower of right-handed neutrinos in the 4D effective theory. We systematically investigate four distinct scenarios for mass generation, considering both Dirac and Majorana mass terms originating from either the bulk or the 3-brane. For each case, we analyse the consequences for neutrino oscillations in a vacuum and in matter, deriving the resulting mass spectra and mixing patterns. By comparing these theoretical predictions with experimental data, we explore the constraints on the large extra dimensions' parameters.

    hep-phJHEP(2026)·7 citations
35. 35*

    Momentum entanglement at colliders: the $H\to WW,ZZ$ case

    J. A. Aguilar-Saavedra🇪🇸

    We address momentum entanglement in Higgs decays to weak boson pairs, $H\to WW,ZZ$, by discretising momentum space. The momenta of the two weak bosons are entangled, as well as the degrees of freedom in momentum and spin spaces. For $H\to ZZ$ in the four-lepton final state, we also estimate the statistical sensitivity of entanglement measures at the Large Hadron Collider and future upgrades. The discretisation method introduced here is broadly applicable, offering a framework for studies of momentum entanglement at the energy frontier.

    hep-phhep-exquant-ph7 citations
36. 36*

    Assessing uncertainties in the determination of the trilinear Higgs self-coupling from single-Higgs observables

    Henning Bahl🇩🇪 · Philip Bechtle🇩🇪 · Johannes Braathen🇩🇪 · Sven Heinemeyer🇪🇸 · Jenny List🇩🇪 · Murillo Vellasco🇩🇪 · Georg Weiglein🇩🇪

    Circular $e^{+}{e}^{-}$ colliders operating at energies below the di-Higgs production threshold can provide information on the trilinear Higgs self-coupling ${\lambda }_{hhh}$ via its loop contributions to single Higgs production processes and electroweak precision observables. We investigate how well a non-SM value of ${\lambda }_{hhh}$ can be determined indirectly via its loop contributions within a global EFT fit. Using an inert doublet extension of the SM Higgs sector as an example for a scenario of physics beyond the SM that could be realised in nature, we find that theoretical uncertainties related to the treatment of loop contributions and the truncation of the EFT expansion, which are usually neglected, play an important role in determining the sensitivity to ${\lambda }_{hhh}$ in a global fit. The results obtained from such an indirect determination of ${\lambda }_{hhh}$ without taking these additional uncertainties into account would be too optimistic, leading to an artificially high resulting precision for ${\lambda }_{hhh}$. They could therefore be misleading in the quest to precisely identify the underlying physics of electroweak symmetry breaking.

    hep-phPoS(2026)·1 citation
37. 37*

    Vacuum structure of the Babu-Nandi-Tavartkiladze model of neutrino mass generation

    Saiyad Ashanujjaman🇩🇪 · Siddharth P. Maharathy🇿🇦

    We analyze the vacuum structure of the Babu--Nandi--Tavartkiladze (BNT) model of neutrino mass generation, in which the Standard Model is extended by an $SU(2{)}_L$ scalar quadruplet with hypercharge $Y=3/2$ and a vector-like $SU(2{)}_L$ triplet fermion with $Y=1$, generating neutrino masses via an effective dimension-seven operator. We delineate the theoretical constraints on the model, requiring the scalar potential to be bounded from below in all field directions, ensuring perturbative unitarity of scattering amplitudes, and demanding that the electroweak vacuum corresponds to the global minimum of the potential. We find that the electroweak vacuum is not generically guaranteed to be the global minimum: several charge-breaking stationary points may coexist with -- and potentially lie below -- it in potential depth. For the electroweak-like vacuum with vanishing quadruplet expectation value, the condition of global stability reduces to two simple mass inequalities involving the doubly- and triply-charged scalars. In contrast, for the general electroweak vacuum with nonzero doublet and quadruplet expectation values -- compatible with neutrino-mass generation -- no comparably simple analytic condition emerges, and the stability must in general be assessed for specific choices of scalar couplings. In the special case where the interaction responsible for neutrino-mass generation vanishes, both electroweak configurations coexist, and the bounded-from-below conditions ensure a definite ordering between them. In this limit, the mass inequalities alone are sufficient to guarantee that the general electroweak vacuum is the global minimum. In the physically relevant regime, the results provide practical sufficient criteria and a systematic framework for assessing vacuum stability in the BNT model.

    hep-phPRD(2026)·1 citation
38. 38*

    Dynamical Heating from Dark Compact Objects and Axion Minihalos: Implications for the 21-cm Signal

    Badal Bhalla🇺🇸 · Aurora Ireland🇺🇸 · Hongwan Liu🇺🇸 · Huangyu Xiao🇺🇸 · Tao Xu🇺🇸

    The temperature of baryons at the end of the cosmic dark ages can be inferred from observations of the 21-cm hyperfine transition in neutral hydrogen. Any energy injection from the dark sector can therefore be detected through these measurements. Dark compact objects and dark-matter substructures can modify the baryon temperature by transferring heat via dynamical friction. In this work, we evaluate the prospects for detecting dynamical friction-induced heating from dark compact objects with a mass in the range $10^2{M}_{\odot }$ to $10^5{M}_{\odot }$, as well as from axion minihalos, using upcoming 21-cm experiments. We find that both the 21-cm global signal and power-spectrum measurements will be sensitive to dark compact objects that constitute about 10% of the dark matter, and will substantially improve our sensitivity to axion-like particles with masses in the range $10^{-18}$ eV to $10^{-9}$ eV.

    ↳ astro-ph.COhep-ph2 citations
39. 39*

    Cross-Geometry Transfer Learning in Fast Electromagnetic Shower Simulation

    Frank Gaede🇩🇪 · Gregor Kasieczka🇩🇪 · Lorenzo Valente🇩🇪

    Accurate particle shower simulation remains a critical computational bottleneck for high-energy physics. Traditional Monte Carlo methods, such as Geant4, are computationally prohibitive, while existing machine learning surrogates are tied to specific detector geometries and require complete retraining for each design change or alternative detector. We present a transfer learning methodology for generative calorimeter simulation models that enables adaptation across diverse geometries with high data efficiency. Using point cloud representations and pre-training on the International Large Detector, our approach handles new configurations without re-voxelizing showers for each geometry. On the CaloChallenge dataset, transfer learning with only 100 target-domain samples achieves a $51\%$ improvement on the geometric mean of Wasserstein distance over training from scratch. Parameter-efficient fine-tuning with bias-only adaptation achieves competitive performance while updating only $17\%$ of model parameters. Our analysis provides insight into adaptation mechanisms for particle shower development, establishing a baseline for future progress of point cloud approaches in calorimeter simulation.

    ↳ physics.ins-dethep-exhep-phphysics.comp-phJINST(2026)·7 citations
40. 40*

    Particle Astrophysics with High and Ultrahigh Energy Neutrinos

    Ke Fang🇺🇸 · Kohta Murase🇺🇸

    We summarize recent results of the observations of high (1 TeV-100 PeV) and ultrahigh ($\ge 100$ PeV) energy neutrinos, including the detection of a diffuse cosmic high-energy neutrino background, the identification of the first neutrino source candidates, and the observation of high-energy neutrinos from the Galactic plane. These findings open a new window to the universe by enabling the use of neutrinos to probe the cosmos that are otherwise inaccessible via photons. Although the origins of most detected neutrinos remain uncertain, we highlight several distinctive features of their sources that have emerged from current observations.

    ↳ astro-ph.HEhep-phEncyclopedia of Particle Physics 3 (2026)…·1 citation
41. 41*

    A Review on Intense Electromagnetic Fields in Heavy-Ion Collisions: Theoretical Predictions and Experimental Results

    Diyu Shen🇨🇳 · Jinhui Chen🇨🇳 · Xu-Guang Huang🇨🇳 · Yu-Gang Ma🇨🇳 · Aihong Tang🇺🇸 · Gang Wang🇺🇸

    In heavy-ion collisions at relativistic energies, the incident nuclei travel at nearly the speed of light. These collisions deposit kinetic energy into the overlap region and create a high-temperature environment where hadrons ``melt'' into deconfined quarks and gluons. The spectator nucleons, which do not undergo scatterings, generate an ultra-intense electromagnetic field -- on the order of $10^{18}$ Gauss at Relativistic Heavy-Ion Collider, and $10^{19}$ Gauss at the Large Hadron Collider. These powerful electromagnetic fields have a significant impact on the produced particles, not only complicating the study of particle interactions but also inducing novel physical phenomena. To explore the nature of these fields and their interactions with deconfined quarks, we provide a detailed overview, encompassing theoretical estimations of their generation and evolution, as well as experimental efforts to detect them. We also provide physical interpretations of the discovered results and discuss potential directions for future investigations.

    ↳ nucl-exhep-phnucl-thResearch(2025)·25 citations
42. 42*

    Probing the three-body force in hadronic systems with specific charge parity

    Ya-Wen Pan🇨🇳 · Ming-Zhu Liu🇨🇳 · Li-Sheng Geng🇨🇳

    Three-body forces, a type of non-perturbative strong interaction, are widely studied in nuclear physics. However, whether their inclusion is necessary in nuclear systems remains a topic of intense debate. In this letter, we propose that the existence of three-body forces in certain three-body hadronic systems with definite $C$-parity is certain. Such systems consist of two components whose interactions are mediated by three-body forces--a mechanism not easily realized in conventional three-nucleon systems. We investigate two specific three-body hadronic systems, ${\bar{D}}_{s}DK$ and ${\bar{D}}^{\ast }D\eta$, using contact-range potentials. The two-body hadron-hadron interactions are constrained by reproducing their scattering lengths, while the three-body couplings are constrained by charge symmetry. Our results indicate that three-body forces play a minor role in binding the $I(J^{PC})=0(0^{--})$ ${\bar{D}}_{s}DK$ system, but a crucial one in binding the $I(J^{PC})=0(1^{-+})$ ${\bar{D}}^{\ast }D\eta$ system. In fact, three-body forces determine whether ${\bar{D}}^{\ast }D\eta$ forms a bound state, making this system a promising candidate for exploring three-body forces in hadronic physics.

    ↳ nucl-thhep-phPRL(2026)·4 citations
43. 43*

    Fermi-liquid view of viscosity in cold and dense nucleon matter

    Jianing Li🇩🇪 · Weiyao Ke🇨🇳 · Jin Hu🇨🇳

    We develop a framework to calculate transport properties in cold, dense relativistic quasiparticle system within the Fermi-liquid theory at the mean-field level. Building on our previous study J. Li \emph{et al.} [Phys. Rev. C \textbf{111}, 044904 (2025)], we start from the linearized relativistic Boltzmann equation tailored to quasiparticles with medium-dependent dispersion relation and implement Landau matching conditions, proving that the bulk viscosity is manifestly nonnegative. A low-temperature expansion then yields leading-order ($T/{\mu }^{\ast }$) expressions for the shear ($\eta$) and bulk ($\zeta$) viscosities, where the behavior $\zeta /\eta \propto (T/{\mu }^{\ast }{)}^4$ in the degenerate regime is found to be robust against quasiparticle mass correction. We couple the kinetic framework to a Walecka-type mean-field equation of state and compute $\eta$ and $\zeta$ for cold, dense nucleon matter. The transport properties of nucleonic matter in the degenerate regime can be relevant for intermediate beam-energy nuclear experiments.

    ↳ nucl-thcond-mat.str-elhep-phhep-thPRC(2026)·0 citations
44. 44*

    Directly computing Wigner functions for open quantum systems

    Nick Huggett🇺🇸 · Christian Käding🇦🇹 · Mario Pitschmann🇦🇹 · James Read🇬🇧

    The Wigner function is a well-known phase space distribution function with many applications in quantum mechanics. In this article, we consider an open quantum system consisting of a non-relativistic single particle interacting with a general, possibly relativistic environment. For this system, we derive an expression for directly computing the time-dependent Wigner function from its initial values. This result renders time-dependent Wigner functions more applicable without having to make additional approximations that would otherwise be required in order to solve the corresponding equation of motion. As an illustration of our findings, we discuss the example of a non-relativistic single scalar particle interacting via a Yukawa interaction with an environment comprising another type of scalar field that is treated relativistically.

    ↳ quant-phhep-phhep-th1 citation
45. 45*

    Nuclear modification of heavy flavor decayed dielectrons in relativistic heavy-ion collisions

    Lejing Zhang🇨🇳 · Wen-Jing Xing🇨🇳 · Shanshan Cao🇨🇳 · Guang-You Qin🇨🇳

    Dielectrons from heavy flavor hadron decays not only constitute a crucial background to their thermal spectrum in high-energy nuclear collisions, from which the temperature of the quark-gluon plasma (QGP) is extracted, but also provide a valuable probe of heavy quark interactions with the QGP. Using a linear Boltzmann transport (LBT) model to describe heavy quark evolution inside the QGP and a hybrid fragmentation-coalescence model for their hadronization, we find heavy quark energy loss softens the invariant mass spectrum of their decayed dielectrons and yields a higher value of the extracted QGP temperature, while coalescence hardens the spectrum and yields a lower value. Taking into account full medium effects leads to higher values of the extracted temperature than using vacuum baselines of heavy flavor decayed dielectrons in analyzing the experimental data. In addition, we find the angular correlations between dielectron pairs are sensitive to heavy quark interactions with the QGP: the radial flow of the QGP enhances the near-side correlations, and scatterings between heavy quarks and the QGP broaden the away-side correlations, with elastic and string interactions playing a dominant role.

    ↳ nucl-thhep-phnucl-exSCPMA(2026)·0 citations
46. 46*

    Quantum computing applications in High Energy Physics: clustering, integration and generative models

    Jorge J. Martínez de Lejarza🇪🇸

    This PhD thesis explores the potential of quantum computing to address computational challenges in high-energy physics (HEP). As the Standard Model (SM) leaves key questions unanswered and no signs of new physics have emerged since the Higgs boson discovery, advanced experimental and computational tools become necessary. Quantum computing offers a promising alternative to classical methods, and this work investigates three main avenues where quantum algorithms can be useful in HEP research. First, we develop quantum subroutines for computing Minkowski distances and identifying maximum values in unsorted data, inserting them into clustering algorithms such as $k$-means, Affinity Propagation, and $k_T$-jet clustering. These quantum algorithms match classical performance while offering theoretical advantages when implemented on quantum hardware with qRAM. Then, we introduce a novel quantum Monte Carlo integrator, Quantum Fourier Iterative Amplitude Estimation (QFIAE), which combines a quantum neural network with amplitude estimation to integrate multivariate functions. QFIAE is executed on simulators and real quantum computers to evaluate Feynman loop integrals via Loop-Tree Duality, and is extended to compute (partially on hardware) a physical observable at NLO in perturbative quantum field theory. Finally, we present Quantum Chebyshev Probabilistic Models (QCPMs) for modeling multivariate distributions, applying them to fragmentation functions of partons fragmenting into kaons and pions. These models demonstrate accurate generative and interpolation capabilities. We also show how entanglement between variables plays a key role in training, enhancing model accuracy. Overall, these results show how quantum algorithms can already tackle relevant HEP problems on current hardware, while paving the way for future fault-tolerant applications that fully exploit quantum computational advantages.

    ↳ quant-phhep-ph0 citations
47. 47*

    Analytical Emulator for the Baryon Density Distribution inside the Fuzzy Dark Matter Soliton from Machine Learning

    Ke Wang🇨🇳 · Jianbo Lu🇨🇳 · Man Ho Chan🇨🇳

    An empirical baryon density profile can be included in the Schrödinger-Poisson (SP) equations to influence the fuzzy dark matter (FDM) soliton formation. However, to probe the effects of baryon on the other dynamical evolutions of the FDM soliton, its equation of motion (EoM) inside the corresponding FDM soliton is needed. In this paper, given an empirical baryon density profile, we first provide the cylindrical symmetric FDM soliton solution about the FDM density and the total potential of FDM and baryon. Then, instead of EoM, we build an analytical emulator (AE) for the baryon density distribution from the obtained FDM density and total potential by machine learning. Finally, we check that this AE works as well as an empirical baryon density profile for the FDM soliton formation, with the fractional errors $\lesssim 0.04$. It should also work as a kind of baryon EoM for some other simple FDM soliton evolutions.

    ↳ astro-ph.COhep-phhep-thPRD(2026)·0 citations
48. 48*

    Equivalence of Stability Criteria for Multi-Fluid Stars

    Tian-Shun Chen🇨🇳 · Xiao-Ding Zhou🇨🇳 · Hao Feng🇨🇳 · Kilar Zhang🇨🇳

    We prove a static criterion for radial zero modes in relativistic multi-fluid stars whose isentropic barotropic components are separately conserved and interact only through gravity. For a regular multi-parameter equilibrium family, the particle-number map is rank deficient if and only if a nontrivial physical radial zero mode exists. The proof establishes a one-to-one correspondence between particle-preserving infinitesimal equilibrium deformations and zero-frequency radial perturbations. We also construct the self-adjoint form realization associated with the coupled pulsation operator, prove that it has compact resolvent, show that its eigenspaces coincide with the physical radial-mode spaces, and establish continuity of every ordered squared mode frequency along the equilibrium family. It follows that every boundary point of strict radial stability within the equilibrium family satisfies the static rank condition. A representative two-fluid example shows that the static criterion and the dynamical zero-mode calculation yield the same critical curve. The rank condition therefore provides an equilibrium-based method for locating radial zero modes and determining their multiplicity.

    ↳ astro-ph.HEgr-qchep-phhep-th+20 citations
49. 49*

    Stability Boundary of Neutron-Dark Matter Mixed Stars

    Xiao-Ding Zhou🇨🇳 · Tian-Shun Chen🇨🇳 · Si-Man Wu🇨🇳 · Kilar Zhang🇨🇳

    Regarding the stability of two-fluid star models, we rigorously prove the equivalence between the emergence of a zero-frequency radial oscillation mode and the static critical-curve criterion for mixed stars, after briefly reviewing the hybrid star case. This establishes a sufficient-condition relation between two independently developed stability criteria. Although this connection has often been implicitly assumed in previous studies of mixed stars, it has rarely been demonstrated explicitly. Our derivation can be extended to general multi-fluid systems. As an illustrative example, we consider dark matter-admixed neutron star models and show that their stability boundary differs from that of single-fluid stars. In this case, stable configurations form a surface in the three-dimensional parameter space spanned by central pressure, mass, and radius, giving rise to a class of stable mixed stars. This class includes "twin stars" with identical masses and radii but distinct internal compositions and structures. These results provide a useful framework for interpreting compact star observations and for constraining dark matter properties through astrophysical measurements.

    ↳ astro-ph.HEgr-qchep-phhep-th+2CPC·3 citations
50. 50*

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

    Alicia C. Postuma (1)🇨🇦 · Garth M. Huber (1)🇨🇦 · D.J. Gaskell (2)🇺🇸 · N. Heinrich (1)🇨🇦 · T. Horn (3 and 2)🇺🇸 · M. Junaid (1)🇨🇦 · S.J.D. Kay (1 and 4)🇨🇦 · V. Kumar (1)🇨🇦 · P. Markowitz (5)🇺🇸 · J. Roche (6)🇺🇸 · R. Trotta (3)🇺🇸 · A. Usman (1)🇨🇦 and 67 other authors

    Deep exclusive meson production (DEMP) reactions, such as $p(\vec{e},e^{\prime }{\pi }^{+})n$, provide opportunities to study the three-dimensional structure of the nucleon through differential cross section and beam- and target-spin asymmetry measurements. This work aims to probe the onset of the hard/soft factorization regime through the exclusive $p(\vec{e},e^{\prime }{\pi }^{+})n$ reaction, as measured in the KaonLT experiment at Jefferson Lab Hall C. A 10.6 GeV longitudinally polarized electron beam was incident on an unpolarized liquid hydrogen target, and the scattered electron and produced meson were detected in two magnetic focusing spectrometers, enabling precision cross section measurements. The cross section ratio ${\sigma }_{L{T}^{\prime }}/{\sigma }_0$ was extracted from the beam-spin asymmetry $A_{LU}$. The $t$-dependence of ${\sigma }_{L{T}^{\prime }}/{\sigma }_0$ was determined at fixed $Q^2$ and $x_B$ over a range of kinematics from $2<Q^2<6$ GeV${}^2$ above the resonance region ($W>2$ GeV). Furthermore, these data are combined with recent results from CLAS/CLAS12 to determine the $Q^2$-dependence of ${\sigma }_{L{T}^{\prime }}/{\sigma }_0$ at two ($x_B$, $t$) settings. This was fairly flat, with $Q^2$ not having a measurable effect on the value of ${\sigma }_{L{T}^{\prime }}/{\sigma }_0$ in the range explored. Results are compared to predictions from the generalized parton distribution (GPD) formalism, which relies explicitly on hard/soft factorization, and Regge formalism. The Regge models better predict ${\sigma }_{L{T}^{\prime }}/{\sigma }_0$, which suggests that the factorization regime is not yet reached.

    ↳ nucl-exhep-exhep-phPLB(2026)·0 citations
51. 51*

    Constraining Dark Acoustic Oscillations with the High-Redshift UV Luminosity Function

    Jared Barron🇺🇸 · David Curtin🇨🇦 · Hongwan Liu🇺🇸 · Julian Munoz🇺🇸 · Sandip Roy🇺🇸

    Dark acoustic oscillations (DAOs) in the matter power spectrum can arise in many different dark sector models, and can imprint on a variety of cosmological observables. In this work we use measurements of the galactic UV luminosity function (UVLF) at high redshifts to constrain the dark acoustic oscillation feature at small scales in a model-agnostic way. We introduce a phenomenological transfer function model for a dark sector with a species undergoing DAOs which can accommodate sub-dominant dark matter abundances, and obtain constraints on its parameters. In order to predict the UVLF, we employ an Extended Press-Schechter formalism which we calibrate using N-body simulations with initial conditions featuring DAOs. Using measurements from the Hubble Space Telescope, James Webb Space Telescope, Subaru Telescope, and Canada-France-Hawaii Telescope, we constrain the wave number of the first DAO peak to be at $k\gtrsim 50h/\mathrm{Mpc}$, unless the fraction of dark matter undergoing DAOs is less than $0.07$.

    ↳ astro-ph.COhep-phJCAP(2026)·10 citations
52. 52*

    Modifications in clusterization procedures for heavy-ion collisions: minimum spanning tree, simulated annealing, coalescence

    Viktar Kireyeu🇷🇺

    A new open-source cluster finding library ''Common Clusterization Library'' (CCL) is proposed to describe the clusters production when applied to the transport codes. The new library was applied to the Parton-Hadron-Quantum-Molecular Dynamics approach to be comparable with the established and well known MST and SACA implementations on the exactly same set of the events. The presented procedures were tested with rapidity density distributions and complex observables like $⟨M_{imf}⟩$ and $⟨Z_{\text{max}}⟩$ vs $Z_{bound}2$ at the energies of ALADiN and NA49 experiments. An improvement to the simulated annealing chain is proposed to reduce the computational time. The new stable clusters tracking algorithm for the ''lost'' cluster recovering is presented. The results of the ''box-like'' coalescence procedure and a mixed method which incorporates the coalescence algorithm steps and the negative binding energy criteria are presented. The difference between the Helium-3 found by the MST-based cluster finding procedure and the coalescence algorithm applied on the exactly same set of events and baryons is shown for the first time.

    ↳ nucl-thhep-phComput.Phys.Commun.(2026)·1 citation
53. 53*

    Possible $\nu$ Source Class: 3-sigma Detection of High-Energy Neutrinos from Supermassive Black Hole Binary Candidates

    Pugazhendhi A D🇮🇳 · Subhadip Bouri🇮🇳 · Bei Zhou🇺🇸 · Rachana🇮🇳 · Ranjan Laha

    Identifying the sources of high-energy (TeV-PeV) astrophysical neutrinos is crucial for studies in both astrophysics and particle physics. Despite extensive searches for more than a decade, which revealed several individual potential sources and only one potential source class, the origins of these neutrinos remain largely unresolved; thus, more source classes should be investigated. In this work, we conduct the first search for high-energy neutrino emission from a new source class, supermassive black hole binaries (SMBHBs), which are also theoretically motivated. We perform an unbinned maximum-likelihood-ratio analysis on our constructed catalog of 693 SMBHB candidates and 10 years of IceCube public data. Our results show positive correlations, with higher significance in more physically motivated scenarios and the highest significance at 3.0$\sigma$. In addition, we also study potential connections between SMBHBs' high-energy neutrino and nano-Hz gravitational-wave emissions, the latter being the main target of pulsar timing arrays. Our results provide the first evidence of SMBHBs being high-energy neutrino emitters.

    ↳ astro-ph.HEastro-ph.COhep-exhep-ph4 citations
54. 54*

    General Four-Loop Beta Function for Scalar-Fermion Theories in Three Dimensions

    York Schröder🇨🇱 · Emmanuel Stamou🇩🇪 · Tom Steudtner🇩🇪 · Max Uetrecht🇩🇪

    We present general four-loop template $\beta$-functions and anomalous field dimensions for renormalisable scalar-fermion theories in three dimensions. By imposing $\mathcal{N}=1$ and $\mathcal{N}=2$ supersymmetry, we obtain relations between the template RGE coefficients, valid in any renormalisation scheme. Directly in $d=3$, we identify a new theory with a non-trivial IR fixed point that is under perturbative control in a large-$N$ limit. We provide up-to-date numerical results for all required massive tadpole master integrals up to four loops and complement them with analytic expressions where available.

    ↳ hep-thcond-mat.str-elhep-phSciPost Phys.(2026)·3 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.