Mon·Jan 20, 2025Monday·January 20, 2025

1. 01*

   Experimental signatures of Kalb-Ramond-like particles

   P. C. Malta🇧🇷 · J. P. S. Melo🇧🇷 · C. A. D. Zarro🇧🇷

   We analyse phenomenological signatures of Kalb-Ramond-like particles, described by an antisymmetric rank-2 tensor, when coupled to fermionic matter. The latter is modelled by a tensor current coupled directly to the Kalb-Ramond field or by a pseudovector current coupled to the rank-1 dual of the field-strength tensor. We obtain limits on the coupling constants to fermions and mass of the Kalb-Ramond-like particles by investigating their impact on the hyperfine splittings of hydrogen, the tree-level unitarity of the $S$ matrix for $e^{-}+e^{+}\to {\ell }^{-}+{\ell }^{+}$ scattering with $\ell \ne e$ and the differential cross section for Bhabha scattering. Assuming that the couplings to fermions are independent of the fermion species, the strongest 95\%-CL bounds we find are from LEP data at $\sqrt{s}=136.23$~GeV, namely $g_{\mathrm{PV}}/\Lambda \lesssim 6.3\times 10^{-13}{\mathrm{eV}}^{-1}$ and $g_{\mathrm{T}}\lesssim 1.3\times 10^{-12}\left(m/\mathrm{eV}\right)$, both for $m\ll \sqrt{s}$ (here $\Lambda$ is a characteristic energy scale). These limits can be improved in upcoming lepton colliders due to enhanced precision, as well as higher energies.

   hep-phhep-thJHEP(2025)·8 citations
2. 02*

   Dirt/Detector/Dump: Complementary BSM production at Short-Baseline Neutrino Facilities

   Bhaskar Dutta🇺🇸 · Debopam Goswami🇺🇸 · Aparajitha Karthikeyan🇺🇸 · Kevin J. Kelly🇺🇸

   Short-baseline neutrino (SBN) facilities are optimal for new-physics searches, including the possible production of new particles in and along the neutrino beamline. One such class of models considers states that are created by neutrino upscattering that then decay in the neutrino detector -- in the past, such upscattering has often been considered to occur in the detector itself (with a prompt decay) or in the dirt upstream of the detector. In this work, we highlight the importance of the beam dumps, situated even further upstream, for such searches. The Fermilab Booster Neutrino Beam, with its iron dump, provides one such possibility. We focus on sub-GeV heavy neutral leptons (HNLs) with a transition magnetic moment, which allows this upscattering to take advantage of the high-$Z$ iron. We observe that, in addition to increased sensitivity to this model at SBND, MicroBooNE, and ICARUS, there exist distinct features in the signal events' kinematical properties when coming from production in the dump, dirt, and detector which can allow for enhanced signal-to-background separation. We highlight the complementarity of this approach to study parameter space relevant for the MiniBooNE low-energy excess, as well as in models in which the HNLs couple to a light scalar particle.

   hep-phhep-exJHEP(2025)·6 citations
3. 03*

   Kaon-induced production of strange hidden-charm molecular pentaquarks $P_{\psi s}^{\Lambda }$ from proton

   Shu Chen🇨🇳 · Jun-Tao Zhu🇨🇳 · Shu-Yi Kong🇨🇳 · Jun He🇨🇳

   In this work, we investigate the kaon-induced production of strange hidden-charm pentaquark $P_{\psi s}^{\Lambda }$ states, including the $P_{\psi s}^{\Lambda }(4459)$ and $P_{\psi s}^{\Lambda }(4338)$ observed by the LHCb collaboration. Coupled-channel interactions involving the channels $\bar{K}N$, ${\Xi }_c^{(\ast )}{\bar{D}}^{(\ast )}$, ${\Xi }_c^{\prime }{\bar{D}}^{(\ast )}$, ${\Lambda }_c{\bar{D}}_s^{(\ast )}$, and $\Lambda J/\psi$ are studied using effective Lagrangians to describe these interactions. The potential kernels are constructed within the one-boson-exchange model and implemented into the quasipotential Bethe-Salpeter equation to calculate the scattering amplitudes. From these amplitudes, the partial-wave cross sections for kaon-induced production are predicted alongside the poles corresponding to strange hidden-charm molecular pentaquarks. The analysis reveals complex structures in the cross sections due to molecular states. A structure near the ${\Xi }_c\bar{D}$ threshold is predicted in the ${\Lambda }_c{\bar{D}}_s$ channel, corresponding to $P_{\psi s}^{\Lambda }(4338)$. Both molecular states near the ${\Xi }_c{\bar{D}}^{\ast }$ threshold with $J^P=1/2^{-}$ and $J^P=3/2^{-}$, associated with $P_{\psi s}^{\Lambda }(4459)$, produce peaks in the ${\Xi }_c^{\prime }\bar{D}$ channel, which vary significantly with the cutoff. Additionally, a molecular state with $J^P=3/2^{-}$ near the ${\Xi }_c^{\ast }\bar{D}$ threshold gives rise to a peak in the ${\Xi }_c{\bar{D}}^{\ast }$ channel. In the higher energy region, from 4350 to 4550 MeV, although the cross sections in the ${\Lambda }_c{\bar{D}}_s^{(\ast )}$ channels are substantial, no distinct structures corresponding to strange hidden-charm pentaquarks are identified, apart from some threshold-related cusps. These results provide valuable theoretical insights and serve as a foundation for future experimental studies of strange hidden-charm pentaquarks using kaon beams at J-PARC and JLab.

   hep-phEPJC(2025)·1 citation
4. 04*

   Solar neutrinos

   Shaomin Chen🇨🇳 · Xun-Jie Xu🇨🇳

   Solar neutrinos, generated abundantly by thermonuclear reactions in the solar interior, offer a unique tool for studying astrophysics and particle physics. The observation of solar neutrinos has led to the discovery of neutrino oscillation, a topic currently under active research, and it has been recognized by two Nobel Prizes. In this pedagogical introduction to solar neutrino physics, we will guide readers through several key questions: How are solar neutrinos produced? How are they detected? What is the solar neutrino problem, and how is it resolved by neutrino oscillation? This article also presents a brief overview of the theory of solar neutrino oscillation, the experimental achievements, new physics relevant to solar neutrinos, and the prospects in this field.

   hep-phastro-ph.SRhep-exnucl-ex6 citations
5. 05*

   Coupled-channel formalism

   José Antonio Oller🇪🇸

   This article provides a pedagogical exploration of coupled-channel scattering in hadronic physics, focusing on theoretical methodologies, and practical applications. It covers key concepts such as the $N/D$ method, Castillejo-Dalitz-Dyson poles, and the generalization of these techniques to coupled channels. The article also presents a parameterization for partial wave amplitudes, ensuring unitarity and analyticity, and addresses scattering near the threshold of dominant channels, with use also of the Lippmann-Schwinger equation. Additionally, it explores final-state interactions, Omnès and Muskhelishvily solutions, the Khuri-Treiman approach, and the two-potential model for resonant event distributions, highlighting the role of Riemann sheets in resonance behavior. These methods are also applicable to related fields like nuclear and atomic physics.

   hep-phnucl-th8 citations
6. 06*

   Collapsing domain walls with ${\mathbb{Z}}_2$-violating coupling to thermalized fermions and their impact on gravitational wave detections

   Qing-Quan Zeng🇨🇳 · Xi He🇨🇳 · Zhao-Huan Yu🇨🇳 · Jiaming Zheng🇨🇳

   We study the dynamics of domain walls formed through the spontaneous breaking of an approximate ${\mathbb{Z}}_2$ symmetry in a scalar field, focusing on their collapse under the influence of quantum and thermal corrections induced by a ${\mathbb{Z}}_2$-violating Yukawa coupling to Dirac fermions in the thermal bath. The thermal effects make the potential bias between the true and false vacua dependent on the temperature and may lead to notable variations in the annihilation temperature of domain walls, in addition to the shift caused by temperature-independent quantum corrections. These modifications could substantially alter the gravitational wave spectrum produced by collapsing domain walls, potentially providing observable signatures for future gravitational wave detection experiments.

   hep-phastro-ph.COgr-qchep-thPRD(2025)·8 citations
7. 07*

   Gluon skewed generalized parton distributions of proton from a light-front Hamiltonian approach

   Pengxiang Zhang🇨🇳 · Yiping Liu🇨🇳 · Siqi Xu🇨🇳 · Chandan Mondal🇨🇳 · Xingbo Zhao🇨🇳 · James P. Vary🇺🇸

   We calculate all leading-twist gluon generalized parton distributions (GPDs) inside the proton at nonzero skewness using the basis light-front quantization framework. The proton's light-front wave functions are derived from a light-front quantized Hamiltonian incorporating Quantum Chromodynamics inputs. Our results show that the qualitative behaviors of the GPDs are consistent with those from other theoretical calculations. Additionally, we analyze the GPDs in the boost-invariant longitudinal coordinate, $\sigma =\frac{1}{2}{b}^{-}{P}^{+}$, which serves as the Fourier conjugate of the skewness. The GPDs in $\sigma$-space exhibit diffraction patterns, reminiscent of optical wave diffraction.

   hep-phhep-thnucl-thPLB(2025)·11 citations
8. 08*

   Leptogenesis in the presence of density perturbations

   Kenta Hotokezaka🇯🇵 · Ryusuke Jinno🇯🇵 · Rin Takada🇯🇵

   We point out a new effect on the freeze-out process of heavy particles induced by density perturbations in the early universe, which we call ``acoustically driven freeze-out.'' This beyond-linear effect is caused by the exponential decoupling of heavy particles from the thermal bath in the presence of density perturbations, and already at moderately large values $\delta T/\bar{T}=O(10^{-2})$ it cannot be captured by linear perturbation theory. We illustrate this effect with leptogenesis taking the decay and inverse decay of heavy neutrinos into account, and discuss its phenomenological implications. We found that perturbations always enhance the (spatially averaged) values of the final lepton asymmetry, and as a result, constraints on the mass of heavy neutrinos are found to be relaxed in the presence of perturbations.

   hep-phastro-ph.COgr-qcPRD(2025)·2 citations
9. 09*

   Scalar fully-charm and bottom tetraquarks under extreme temperatures

   A. Aydın🇹🇷 · H. Sundu🇹🇷 · J.Y. Süngü🇹🇷 · E. Veli Veliev🇹🇷

   Temperature dependences of masses and current couplings of the ground state of the fully heavy tetraquarks $T_{4c}$ and $T_{4b}$, composed of charm $(c)$ and bottom $(b)$ quarks and antiquarks with spin-parities $J^{PC}=0^{++}$ are evaluated in the diquark antidiquark picture using Thermal QCD Sum Rules including vacuum condensates up to dimension four. The calculated values for $cc\bar{c}\bar{c}$ and $bb\bar{b}\bar{b}$ tetraquark states at $T=0$ align well with the experimental data on the broad structures. Based on the numerical analyses around the critical temperature, the mass of the $T_{4c}$ state decreases by $8\%$ compared to its vacuum state, while for its b partner, this percentage is approximately $3.3\%$. For the decay constants, the reductions are approximately $71\%$ and $66.6\%$, respectively. The precise exploration of tetraquark states awaits future scrutiny in upcoming experiments, including Belle II, Super-B, PANDA, and LHCb.

   hep-phEPJC(2025)·8 citations
10. 10*

    Binary superfluids: Low-energy properties and dissipative processes from spontaneous emission of massive phonons

    Silvia Trabucco🇮🇹 · Luca Lepori🇫🇷 · Maria Luisa Chiofalo🇮🇹 · Massimo Mannarelli🇮🇹

    We discuss the low-energy properties of binary superfluids with density-dependent interactions. Adding an intra-species coupling that induces an explicit soft symmetry-breaking, we determine the background pressure and we show that the low-energy spectrum consists of a massless Nambu- Goldstone boson and a massive (pseudo) Nambu-Goldstone boson. When the background velocities of the two superfluids are transonic, the system is characterized by two distinct acoustic horizons: the hydrodynamic analogue of the black hole event horizon. The Hawking-like emission occurring at these horizons produces an effective friction on the fluids. We compute the viscosity-to-entropy ratios close to the two acoustic horizons, finding that the emission of pseudo Nambu-Goldstone bosons violates the bound conjectured by Kovtun, Son and Starinet.

    hep-phcond-mat.quant-gasgr-qcquant-phPRD(2025)·6 citations
11. 11*

    Pauli principle forbids ${\Omega }_{QQQ}{\Omega }_{QQQ}{\Omega }_{QQQ}$ bound states

    H. Garcilazo🇲🇽 · A. Valcarce🇪🇸

    Lattice QCD studies have shown the attractive character of the ${}^1{S}_0$ ${\Omega }_{QQQ}{\Omega }_{QQQ}$, $Q=s,c,b$, interaction, predicting deeply bound states as the mass of the heavy quark increases. This has led to the question of the possible existence of bound states of more than two ${\Omega }_{QQQ}$ baryons, in particular ${\Omega }_{QQQ}{\Omega }_{QQQ}{\Omega }_{QQQ}$ bound states. We discuss how these states might not exist in nature in any flavor sector. The reason would be due to the simultaneous action of two consequences of the Pauli principle in the different partial waves: one at the baryon level, affecting the ${}^1{S}_0$ partial wave, and the other due to the quark substructure, affecting the ${}^5{S}_2$ partial wave.

    hep-phnucl-thPRD(2025)·1 citation
12. 12*

    ${\Omega }_{bbb}{\Omega }_{bbb}{\Omega }_{bbb}$ tribaryons

    H. Garcilazo🇲🇽 · A. Valcarce🇪🇸

    We study the possible existence of bound states of three ${\Omega }_{bbb}$ baryons. We consider only $S$ wave interactions and we start from recent lattice QCD results which give a strongly attractive potential between two ${\Omega }_{bbb}$ baryons in the ${}^1{S}_0$ channel. We analyze different scenarios. At baryonic level, the ${\Omega }_{bbb}{\Omega }_{bbb}$ interaction could be understood to be basically spin-independent, so that the two contributing channels, ${}^1{S}_0$ and ${}^5{S}_2$, would have a very similar interaction. This baryonic analysis leads to the existence of bound states in the three-body system. At the quark level, repulsive effects would appear in the ${}^5{S}_2$ channel, making it more repulsive than the ${}^1{S}_0$ channel. We study the effect of such repulsion in terms of its range.

    hep-phnucl-thRev.Mex.Fis.(2024)·3 citations
13. 13*

    Soft gluon resummation for gluon fusion $ZH$ production

    Goutam Das🇩🇪 · Chinmoy Dey🇮🇳 · M. C. Kumar🇮🇳 · Kajal Samanta🇬🇧

    We examine the effects of soft gluons on Higgs boson production in association with a $Z$ boson at the Large Hadron Collider (LHC). Utilizing the universal cusp anomalous dimensions and splitting kernels, we analyze effects of soft gluons on the gluon fusion $ZH$ process, focusing on the total production cross-section as well as the invariant mass distribution at the next-to-leading logarithmic level. Additionally, we estimate the next-to-soft effects on this subprocess to the same level of accuracy. A detailed phenomenological analysis is performed for the $13.6$ TeV LHC. Finally, combining these results with those from other subprocesses, we provide comprehensive predictions for the $ZH$ production cross-section and the invariant mass distribution that will be valuable for comparison with experimental data from the upcoming LHC run as well as the future hadron colliders.

    hep-phPRD(2026)·12 citations
14. 14*

    Exploring the Standard Model and Beyond from the Evidence of CE$\nu$NS with Reactor Antineutrinos in CONUS+

    M. Alpízar-Venegas🇲🇽 · L. J. Flores🇲🇽 · Eduardo Peinado🇲🇽 · E. Vázquez-Jáuregui🇲🇽

    The observation of the Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS) process using reactor antineutrinos offers a unique opportunity to probe the Standard Model and explore Beyond the Standard Model scenarios. This study reports on the latest results from the CONUS+ experiment conducted at the Leibstadt nuclear power plant (KKL), Switzerland. The CONUS collaboration reports $395\pm 106$ events detected from reactor antineutrinos with an exposure of 347 kg$\cdot$days, utilizing high-purity germanium detectors operated at sub-keV thresholds. A ${\chi }^2$-based statistical analysis was performed on these results, incorporating systematic uncertainties. This analysis was used to extract the weak mixing angle, establish a limit on the neutrino magnetic moment, and impose constraints on neutrino non-standard interactions using reactor antineutrinos. The results confirm the potential of CE$\nu$NS experiments in the study of fundamental neutrino properties and probing new physics.

    hep-phPRD(2025)·24 citations
15. 15*

    Parton distributions confront LHC Run II data: a quantitative appraisal

    Amedeo Chiefa🇬🇧 · Mark N. Costantini🇬🇧 · Juan Cruz-Martinez🇨🇭 · Emanuele R. Nocera🇮🇹 · Tanjona R. Rabemananjara🇳🇱 · Juan Rojo🇳🇱 · Tanishq Sharma🇮🇹 · Roy Stegeman🇬🇧 · Maria Ubiali🇬🇧

    We present a systematic comparison of theoretical predictions and various high-precision experimental measurements, specifically of differential cross sections performed by the LHC run II for Drell-Yan gauge boson, top-quark pair, single-inclusive jet and di-jet production, and by HERA for single-inclusive jet and di-jet production. Theoretical predictions are computed at next-to-next-to-leading order (NNLO) accuracy in perturbative Quantum Chromodynamics. The most widely employed sets of Parton Distribution Functions (PDFs) are used, and PDF, strong coupling, and missing higher order uncertainties are taken into account. We quantitatively assess the predictive power of each PDF set and the contribution of the different sources of experimental and theoretical uncertainty to the agreement between data and predictions. We show that control over all of these aspects is crucial to precision physics studies, such as the determination of Standard Model parameters at the LHC.

    hep-phhep-exJHEP(2025)·19 citations
16. 16*

    Excited s-wave $1^{--}$ vector mesons, their leptonic decays and (in-)complete absence of abnormal states as seen from the constituent quark BSE

    V. Sauli🇨🇿

    Within a lattice inspired interaction between quark and antiquark, we obtain a hierarchy of solutions to the Bethe-Salpeter equation (BSE) for vector quarkonia excited states in the constituent quark mass approximation. As a toy model, we apply the similar to calculate ground and excited states of $\varphi$ and $\omega /\rho$ meson. Through detailed numerical searches, our study provides evidence that the single-valued constant mass quark propagator does not yield known meson spectra without the simultaneous presence of abnormal (unphysical) solutions. We classify normal and abnormal solutions and discuss necessary changes in the calculation scheme to avoid the spectrum of inconsistent solutions. While all experimental narrow vector mesons are identified with a normal state of the BSE, the occurrence of mutually cancelled normal-abnormal states are reported. The results are slightly different for the heavy and light mesons, but in both cases they seem to result from the inconsistent use of the hmogeneous BSE to describe broad resonances.

    hep-phhep-exnucl-thNPA(2025)·1 citation
17. 17*

    (H)ALPing the 511 keV line: A thermal DM interpretation of the 511 keV emission

    Mohammad Aghaie🇮🇹 · Pedro De la Torre Luque🇪🇸 · Alessandro Dondarini🇮🇹 · Daniele Gaggero🇮🇹 · Giulio Marino🇮🇹 · Paolo Panci🇮🇹

    We propose a novel framework where MeV-scale Dirac Dark Matter annihilates into axion-like particles, providing a natural explanation for the 511 keV gamma-ray line observed in the Galactic Center. The relic abundance is determined by p-wave annihilation into two axion-like particles, while s-wave annihilation into three axion-like particles, decaying into $e^{+}{e}^{-}$ pairs, accounts for the line intensity. Remarkably, this model, assuming a standard Navarro-Frenk-White profile, reproduces the observed emission morphology, satisfies in-flight annihilation and cosmological bounds, and achieves the correct relic density, offering a compelling resolution to this longstanding anomaly.

    hep-phastro-ph.COastro-ph.HEPLB(2026)·14 citations
18. 18*

    Environmental effects in extreme mass ratio inspirals: perturbations to the environment in Kerr

    Conor Dyson🇩🇰 · Thomas F.M. Spieksma🇩🇰 · Richard Brito🇵🇹 · Maarten van de Meent🇩🇰 · Sam Dolan🇬🇧

    Future gravitational wave observatories open a unique avenue to study the environments surrounding black holes. Intermediate or extreme mass ratio inspirals will spend thousands to millions of cycles in the sensitivity range of detectors, allowing subtle environmental effects to accumulate in the gravitational waveform. Working in Lorenz gauge and considering equatorial circular orbits, we present the first self-consistent, fully relativistic calculation of a perturbation to a black hole environment due to an inspiraling secondary in the Kerr geometry. As an example case, we consider the environment to be that of a superradiantly grown scalar cloud, though our framework is generalizable to other scenarios. We demonstrate that the scalar field develops a rich wake structure induced by the secondary and compute scalar fluxes emitted to infinity and through the horizon. Relative differences in the fluxes compared to Schwarzschild are tens of percent on large intervals of parameter space, underscoring the importance of modeling in Kerr.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRL(2025)·87 citations
19. 19*

    More varieties of 4-d gauge theories: product representations

    Ben Gripaios🇬🇧 · Khoi Le Nguyen Nguyen🇬🇧

    Recently, we used methods of arithmetic geometry to study the anomaly-free irreducible representations of an arbitrary gauge Lie algebra. Here we generalize to the case of products of irreducible representations, where it is again possible to give a complete description. A key result is that the projective variety corresponding to $m$-fold product representations of the Lie algebra ${\mathfrak{su}}_n$ is a rational variety for every $m$ and $n$. We study the simplest case of ${\mathfrak{su}}_3$ (corresponding to the strong interaction) in detail. We also describe the implications of a number-theoretic conjecture of Manin (and related theorems) for the number of chiral representations of bounded size $B$ (measured roughly by the Dynkin labels) compared to non-chiral ones, giving a precise meaning to the sense in which the former (which are those most relevant for phenomenology) are rare compared to the latter. As examples, we show that, for both irreducible representations of ${\mathfrak{su}}_5$ and once-reducible product representations of ${\mathfrak{su}}_3$ that are non-anomalous, the number of chiral representations is asymptotically between $B(\log B{)}^5$ and $B^{\frac{4}{3}}$, while the number of non-chiral representations is asymptotically $B^2$. Despite this rarity of chiral, anomaly-free, product representations, we show that there are examples relevant for phenomenology, including one that gives an asymptotically-free gauge theory with Lie algebra ${\mathfrak{su}}_7$.

    ↳ hep-thhep-phmath.AGJHEP(2025)·3 citations
20. 20*

    Quantum field theory on curved manifolds

    Tomohiro Matsuda🇯🇵

    This paper discusses how particle production from the vacuum can be explained by local analysis when the field theory is defined by differential geometry on curved manifolds. We have performed the local analysis in a mathematically rigorous way, respecting the Markov property. The exact WKB is used as a tool for extracting non-perturbative effect from the local system. After a serious application of the differential geometry and the exact WKB to particle production, we show that entanglement does not appear in the Unruh effect as far as the standard formulation by the differential geometry is valid. This result should not be attributed to a consistency problem between the ``entanglement state'' and the ``standard field theory by differential geometry'', but to the fact that the conventional calculation of the Unruh effect is done by extrapolation which is not consistent with the differential geometry. The situation is similar to that of the Dirac monopole, but topology is not relevant and the basis for building field theories in differential geometry is strongly involved.

    ↳ hep-thgr-qchep-phInt.J.Mod.Phys.A(2025)·3 citations
21. 21*

    Fully viable DHOST bounce with extra scalar

    Ok Song An🇰🇵 · Jin U Kang🇰🇵 · Yong Jin Kim🇰🇵 · Ui Ri Mun🇰🇵 · Un Gyong Ri🇰🇵

    In this paper we construct a class of Degenerate Higher-Order Scalar-Tensor (DHOST) theories with an extra scalar field, which admits viable solutions of bouncing universe satisfying the following requirements: (i) absence of Belinski-Khalatnikov-Lifshitz (BKL) instability, ghost and gradient instability, (ii) absence of superluminality, (iii) generation of nearly scale-invariant curvature perturbations and very small tensor-to-scalar ratio, and (iv) conventional asymptotics in the distant past and future, where gravity sector is described by General Relativity and the DHOST scalar has a canonical form of Lagrangian. We also expect our models to have sufficiently small non-Gaussianities of primordial curvature perturbations to be compatible with observations. As such, this work exemplifies for the first time the fully viable two-field DHOST bouncing cosmology, which is free of instability and superluminality problems as well as compatible with observations.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2025)·5 citations
22. 22*

    Nuclear equation of state at finite ${\mu }_B$ using deep learning assisted quasi-parton model

    Fu-Peng Li🇨🇳 · Long-Gang Pang🇨🇳 · Guang-You Qin🇨🇳

    To accurately determine the nuclear equation of state (EoS) at finite baryon chemical potential (${\mu }_B$) remains a challenging yet essential goal in the study of QCD matter under extreme conditions. In this study, we develop a deep learning assisted quasi-parton model, which utilizes three deep neural networks, to reconstruct the QCD EoS at zero ${\mu }_B$ and predict the EoS and transport coefficient $\eta /s$ at finite ${\mu }_B$. The EoS derived from our quasi-parton model shows excellent agreement with lattice QCD results obtained using Taylor expansion techniques. The minimum value of $\eta /s$ is found to be approximately 175 MeV and decreases with increasing chemical potential within the confidence interval. This model not only provides a robust framework for understanding the properties of the QCD EoS at finite ${\mu }_B$ but also offers critical input for relativistic hydrodynamic simulations of nuclear matter produced in heavy-ion collisions by the RHIC beam energy scan program.

    ↳ nucl-thhep-phPLB(2025)·11 citations
23. 23*

    Neutrino Experiments at the Large Hadron Collider

    Akitaka Ariga🇨🇭 · Jamie Boyd🇨🇭 · Felix Kling🇩🇪 · Albert De Roeck🇨🇭

    The proton-proton collisions at the Large Hadron Collider (LHC) produce an intense, high-energy beam of neutrinos of all flavors, collimated in the forward direction. Recently two dedicated neutrino experiments, FASER and SND@LHC, have started operating to take advantage of the TeV energy LHC neutrino beam, with first results released in 2023 and further results released in 2024. The first detection of neutrinos produced at a particle collider opens up a new avenue of research, allowing to study the highest energy neutrinos produced in a controlled laboratory environment, with an associated broad and rich physics program. Neutrino measurements at the LHC will provide important contributions to QCD, neutrino and BSM physics, with impactful implications for astro-particle physics. This review article summarizes the physics motivation, status and plans of, present and future neutrino experiments at the LHC.

    ↳ hep-exhep-phAnn.Rev.Nucl.Part.Sci.(2025)·17 citations
24. 24*

    From QCD phenomenology to nuclear physics phenomenology: the chiral confining model

    Guy Chanfray🇫🇷 · Magda Ericson🇫🇷 · Hubert Hansen🇫🇷 · Jérôme Margueron🇺🇸 · Marco Martini🇫🇷

    We present a theoretical framework allowing to make an explicit connection between the phenomenology of QCD, namely the properties of the gluon correlator and Wilson loops, and a particular relativistic model for the description of nuclear matter and neutron stars, the chiral confining model. Starting with the Field Correlator Method, which incorporates explicitly and simultaneously confinement and chiral symmetry breaking, we describe how to obtain the response of the composite nucleon to the nuclear scalar field, the relative role of confinement and chiral symmetry breaking in the in-medium nucleon mass evolution, generating the three-body forces needed for the saturation mechanism.

    ↳ nucl-thhep-phSymmetry(2025)·4 citations
25. 25*

    From Many Models to ONE THEORY

    J. Iliopoulos🇫🇷

    The year 2024 marks two anniversaries: The 70th anniversary of CERN and the 50th anniversary of the $J/\Psi$ discovery. At this occasion I have been asked to give review talks on the significance of these anniversaries. This article is an expanded version of these talks.

    ↳ physics.hist-phhep-phhep-thHiHEP(2025)·4 citations
26. 26*

    DeepSSM: an emulator of gravitational wave spectra from sound waves during cosmological first-order phase transitions

    Chi Tian🇨🇳 · Xiao Wang🇦🇺 · Csaba Balázs🇦🇺

    We present DeepSSM, an open-source code powered by neural networks (NNs) to emulate gravitational wave (GW) spectra produced by sound waves during cosmological first-order phase transitions in the radiation-dominated era. The training data is obtained from an enhanced version of the Sound Shell Model (SSM), which accounts for the effects of cosmic expansion and yields more accurate spectra in the infrared regime. The emulator enables instantaneous predictions of GW spectra given the phase transition parameters, while achieving agreement with the enhanced SSM model within 10\% accuracy in the worst-case scenarios. The emulator is highly computationally efficient and fully differentiable, making it particularly suitable for direct Bayesian inference on phase transition parameters without relying on empirical templates, such as broken power-law models. We demonstrate this capability by successfully reconstructing phase transition parameters and their degeneracies from mock LISA observations using a Hamiltonian Monte Carlo sampler. The code is available at: https://github.com/ctian282/DeepSSM.

    ↳ astro-ph.COhep-phJCAP(2025)·8 citations
27. 27*

    A precise study of the SU(3) Yang-Mills theory across the deconfinement transition

    Leonardo Giusti (Milan Bicocca U. and INFN, Milan Bicocca)🇮🇹 · Mitsuaki Hirasawa (Milan Bicocca U. and INFN, Milan Bicocca)🇮🇹 · Michele Pepe (INFN, Milan Bicocca)🇮🇹 · Luca Virzì (Milan Bicocca U. and INFN, Milan Bicocca)🇮🇹

    We perform a detailed computation of key quantities across the first-order deconfinement phase transition of the SU(3) Yang-Mills theory. Specifically, we calculate the entropy density, $s(T_c)/T_c^3$, on both sides of the transition and determine the latent heat $h$. The calculations are carried out in the lattice regularization with the Wilson action, employing shifted boundary conditions in the temporal direction. Our simulations are performed at five different values of the lattice spacing in order to extrapolate the results to the continuum limit. The latent heat can be measured also as the discontinuity in the trace anomaly of the energy-momentum tensor: our result using the entropy density is compatible with the one obtained from the trace anomaly, giving a combined estimate $h=1.175(10)$. Additionally, we determine the critical temperature $T_c$ in physical units with permille accuracy, yielding $T_c\sqrt{t_0}=0.24915(29)$. These results allow to connect with precision the confined and the deconfined phases and we present an improved computation of the Equation of State across the deconfinement transition for $T$ between 0 and $3.4T_c$.

    ↳ hep-lathep-phPLB(2025)·22 citations
28. 28*

    Constituent Quark-model for BaryonsTh. Harmonic confinement and Two-body Meson-exchange Potentials

    Th.A. Rijken🇳🇱

    Soft Two-body potentials between the constituent quarks of the nucleon are derived using harmonic oscillator, i.e. gaussian, quark wave-functions. The gaussian wave-functions are very suited for applications with the ESC soft-core interactions, which employ gaussian form factors. In these notes using the Fourier transformation to momentum space the local and non-local contributions of the potentials based on the ESC meson-quark-quark vertices are evaluated. Using the ESC16 parameters translated to the quark-level leads to parameter free two-body and three-body diquark and triquark meson-exchange interactions. Applications to the SU(3) baryon-octet states and the ${\Delta }_{33}$ resonance are performed., within the CQM using a harmonic confinement potential, leading to a satisfactory picture with relativistic constituent quarks. We present two versioins for the $N-\Delta$ splitting: (i) model A with the instanton interaction, and (ii) model B with a large color-magnetic interaction from an almost point like OGE. The size of the baryons $\approx$ 1 fm.

    ↳ nucl-thhep-ph0 citations
29. 29*

    Unnuclear matter at large-charge

    Silas R. Beane🇨🇭 · Domenico Orlando🇨🇭 · Susanne Reffert🇨🇭

    The utility of the non-relativistic large-charge EFT for physical systems, and neutron matter in particular, relies on controlled Schrödinger-symmetry breaking deformations due to scattering length and effective-range effects in the two-body system. A recently-found exact solution of the large-charge system is used to compute these effects for two-point correlation functions of large-charge operators in perturbation theory around the large-charge ground state. Notably, the leading effective-range effects are found to enter at second order in the effective range, in agreement with analogous calculations in the three-body system. The Schrödinger-symmetry breaking deformations are used -- together with input from Quantum Monte Carlo simulations -- to address the range of validity of the EFT with deformations both in general and in the special case of neutron matter. In particular, it is found that nuclear reactions with up to six low-energy neutrons in the final state can be described by the large-charge EFT with Schrödinger-symmetry breaking.

    ↳ nucl-thhep-phhep-thPRD(2025)·5 citations
30. 30*

    Four-quark operators with $\Delta F=2$ in the GIRS scheme

    M.Constantinou · M. Costa · H. Herodotou🇨🇾 · H.Panagopoulos · G. Spanoudes🇨🇾

    We calculate the mixing matrices of four-quark operators that change flavor numbers by two units. Our approach employs two schemes: the coordinate-space Gauge Invariant Renormalization Scheme (GIRS) and the Modified Minimal Subtraction scheme. From our perturbative computations, we extract the conversion factors between these two renormalization schemes at the next-to-leading order. A significant challenge in the study of four-quark operators is that they mix among themselves upon renormalization. Additionally, computations in GIRS at a given order in perturbation theory require Feynman diagrams with at least one additional loop. The extraction of the conversion factors involves calculating two-point Green's functions, which include products of two four-quark operators, and three-point Green's functions, which involve one four-quark operator and two bilinear operators, with all operators located at distinct spacetime points. We investigate both parity-conserving and parity-violating four-quark operators. This calculation is relevant to the determination of Cabibbo-Kobayashi-Maskawa (CKM) matrix elements from numerical simulations using the GIRS scheme.

    ↳ hep-lathep-phPoS(2025)·0 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.