Fri·Dec 27, 2024Friday·December 27, 2024

1. 01*

   Impact of resummation on the production and experimental bounds of scalar high-electric-charge objects

   Jean Alexandre🇬🇧 · Nick E. Mavromatos🇬🇷 · Vasiliki A. Mitsou🇪🇸 · Emanuela Musumeci🇪🇸

   A one-loop Dyson-Schwinger-like resummation scheme is applied to scalar High-Electric-Charge compact Objects (HECOs), extending previous work on spin-1/2 case. The electromagnetic interactions of HECOs are considered within the framework of strongly coupled scalar Quantun Electrodynamics. The resummation amounts to determining non-trivial ultraviolet (UV) fixed points, at which the effective Lagrangian, which will lead to the pertinent predictions on the cross sections, is computed. In contrast to the fermionic HECO case, in which the fixed point structure was determined solely by the interactions of the HECOs with the photon field, in the scalar case the existence of non-trivial UV fixed points requires the presence of additional strong self interactions among the HECOs. Our resummation scheme, which is notably different from a lattice strong-coupling approach, makes the computation of the pertinent scalar-HECO-production cross sections reliable, thus allowing revisiting the mass bounds obtained from searches for such objects in current or future colliders. Our MadGraph implementation of the results leads to enhanced (up to ~30%) lower bounds on the mass of scalar HECOs, as compared to those extracted from the tree-level processes typically used in LHC collider searches by ATLAS and MoEDAL experiments.

   hep-phhep-exPRD(2025)·9 citations
2. 02*

   Coarse-grained binning in Drell-Yan transverse momentum spectra

   Wenxiao Zhan🇨🇳 · Siqi Yang🇨🇳 · Minghui Liu🇨🇳 · Francesco Hautmann🇬🇧 · Liang Han🇨🇳

   We report a study of the determination of the intrinsic transverse momentum of partons, the intrinsic $k_T$, from the dilepton transverse momentum $p_T$ in Drell-Yan (DY) production at hadron colliders. The result shows that a good sensitivity to the intrinsic $k_T$ distribution is achieved by measuring relative ratios between the cross sections of suitably defined low-$p_T$ and high-$p_T$ regions. The study is performed through both a pseudo-data test and an extraction from measurements of the DY process by the CMS collaboration. Since the methodology does not rely on any dedicated partition of bins, this $p_T$-ratio observable requires less special treatment in very low $p_T$ regions, and propagates lower systematic uncertainties induced from unfolding or momentum migration, in contrast with previous proposals of using a fine-binning measurement of the differential cross section.

   hep-phPRD(2025)·5 citations
3. 03*

   Are the new particles heavy or light in $b\to s{E}_{\mathrm{miss}}$?

   Quan-Yi Hu🇨🇳

   In this work, we study the $B^{+}\to K^{+}{E}_{\mathrm{miss}}$, $B^0\to K^{\ast 0}{E}_{\mathrm{miss}}$, and ${\Lambda }_b^0\to {\Lambda }^0{E}_{\mathrm{miss}}$ decays under three different new physics hypotheses: the heavy new particles, the light neutral vector particles, and the axion-like particles. We find that all three hypotheses can resolve the Belle-II excess, and they can be clearly distinguished by the longitudinal polarization fraction of $K^{\ast }$. Furthermore, we discover that the longitudinal polarization fraction of $\Lambda$ can be used to distinguish the chirality of the effective operators.

   hep-phEPJC(2025)·18 citations
4. 04*

   Dark matter from axion and small neutrino mass

   Shivam Gola🇮🇳

   We explore a KSVZ-like extension of the Standard Model with a Dirac fermion and three right-handed neutrinos. PQ symmetry allows the Dirac mass for neutrinos and prevents the Majorana mass. A ${\mathcal{Z}}_2$ symmetry guarantees the stability of Dirac fermion dark matter. The breakdown of PQ symmetry generates the QCD axion at a high scale. The fermion dark matter relic abundance arises from the UV-freeze-in mechanism through the axion portal. We determine the fermion DM relic by solving the coupled Boltzmann equations and finding the allowed parameter space using the relic density constraints. Having determined the allowed parameter space for fermion DM, we also look for non-thermal axion production schemes to seek the two DM possibility. We find that FIMP alone is a suitable dark matter that is not excluded while considering several current bounds and future sensitivities on axion and dark matter. Our study highlights the interlinking of dark matter, axion, and neutrinos while addressing the strong CP problem and small neutrino masses.

   hep-phPRD(2025)·1 citation
5. 05*

   Study of rare top quark decays into a jet plus a charged pseudo-scalar meson

   Long-Shun Lu🇨🇳 · Lei-Yi Li🇨🇳 · Cai-Dian Lü🇨🇳

   The semi-inclusive decay processes of a top quark into a charged pseudo-scalar meson and a jet are studied within the framework of QCD factorization. The leading power of the decay matrix elements can be factorized into heavy-to-light quark transition current and a hadron matrix element up to next-to-leading order QCD corrections. We calculate one-loop virtual corrections together with real gluon emission corrections at the {\alpha}s order. The numerical results of the branching ratios are presented for the sum of two-body and three-body decays. We also study the energy cut-off dependence of the gluon jet. These processes are hopeful to be detected in the near future experiments, which can serve as probes for new physics.

   hep-phPRD(2025)·0 citations
6. 06*

   New Physics in the 3-3-1 models

   H. N. Long🇻🇳

   Two main ingredients of current particle physics such as local gauge symmetry and mass generation via the Higgs mechanism being basic ground of the Standard Model are widely confirmed by experimental data. However, some problems such as neutrino masses, dark matter, baryon asymmetry of Universe have clearly indicated that the Standard Model cannot be the ultimate theory of nature. To surpass the mentioned puzzles, many extensions of the Standard Model (called beyond Standard Model) have been proposed. Among beyond Standard Models, the 3-3-1 models have some intriguing features and they get wide attention. The pioneer models develop in some directions. In this paper, %some new main versions of the 3-3-1 models and their consequences are presented.

   hep-phCommun.in Phys.(2024)·3 citations
7. 07*

   Leptophilic Axion-like Particles at Forward Detectors

   Xu-Hui Jiang🇨🇳 · Chih-Ting Lu🇨🇳

   Leptophilic axion-like particles (ALPs) exhibit rich phenomenology, focusing exclusively on interactions between an ALP and Standard Model (SM) leptons. Through integration by parts, it is shown that both the three-point interaction, $a\bar{\ell }\ell$ and the four-point interaction, $a{\ell }^{-}\nu W^{+}$, play significant roles, making the flavor portal particularly compelling. For ALPs with masses ranging from $\mathcal{O}(1)$ MeV to $\mathcal{O}(1)$ GeV, they can contribute to exotic hadron decays. Suppressed couplings naturally extend the ALP lifetime, presenting opportunities for detection at forward detectors. In this study, we explore ALPs with both electrophilic and muonphilic scenarios. We propose an inclusive search for various hadrons that undergo exotic decays at the Large Hadron Collider (LHC). In the electrophilic scenario, long-lived ALPs are searched in the Forward Search Experiment (FASER) and its upgrading phase, FASER II. In the muonphilic scenario, where the ALP lifetime is significantly reduced due to its coupling to muons, we further investigate its detection potential at LHCb and its high-luminosity upgrade. Several benchmarks are analyzed, including electroweak-preserving, electroweak-violating and left-right softly asymmetric models, to demonstrate possible experimental constraints.

   hep-phhep-exPRD(2025)·13 citations
8. 08*

   Simulations of the Sterile Neutrino Oscillations with a Crossing-Width Term

   Qiankang Wang🇨🇳 · DaYun Qiu🇨🇳 · Yi-Lei Tang🇨🇳

   In this paper, we present an algorithm to generate the collider events of the GeV-scale oscillating sterile neutrinos with the ready-made event generation tools in the case that the crossing-widths among the nearly-degenerate fermionic fields arise. We prove the validity of our algorithm, and adopt some tricks for practical calculations. The formulations of the particle oscillation processes are also improved in the framework of the quantum field theory, offering us the ability to simulate the flying distances of the oscillating intermediate sterile neutrinos while regarding them as the internal lines in the Feynmann diagrams.

   hep-phhep-thJHEP(2025)·0 citations
9. 09*

   Violation of Parity and Flavor Symmetries in a Nambu-Jona-Lasinio Model

   Yukimi Goto🇯🇵 · Tohru Koma🇯🇵

   We study a lattice Nambu-Jona-Lasinio model with certain continuous chiral and two-flavor symmetries. For the Hamiltonian of the model, we construct a ground state which breaks the parity and flavor symmetries. In our argument, the chiral symmetry plays a crucial role for proving the violation of the parity and flavor symmetries, although the model does not contain the so-called Wilson term.

   hep-phcond-mat.stat-mechhep-latmath-ph+10 citations
10. 10*

    Exploring $Z^{\prime }$ and Right-Handed Neutrinos in the BLSM at the Large Hadron Collider

    Nidal Chamoun🇸🇾 · Kareem Ezzat🇪🇬 · Shaaban Khalil🇪🇬 · Rhitaja Sengupta🇩🇪

    We study the collider phenomenology of the $B$-$L$ extension of the Standard Model (BLSM), focusing on the production and decay of a heavy neutral gauge boson (\( Z' \)) at the Large Hadron Collider (LHC). In this framework, the \( Z' \) can decay into pairs of heavy right-handed neutrinos (\( \nu_R \)), which subsequently decay into charged leptons and \( W \) bosons. These processes give rise to three distinctive final states: (i) two leptons plus four jets (\( 2\ell + 4j \)), (ii) four leptons plus missing transverse energy (\( 4\ell + \text{MET} \)), and (iii) three leptons plus two jets and MET (\( 3\ell + 2j + \text{MET} \)). % To enhance signal sensitivity and suppress Standard Model backgrounds, we employ multivariate analysis techniques based on Boosted Decision Trees (BDTs), as well as selection optimizations using the \texttt{XGBOOST} framework. The classifiers are trained on kinematic observables sensitive to the masses of the \( Z' \) and \( \nu_R \). We demonstrate that all three final states offer significant discovery potential for both the \( Z' \) and heavy \( \nu_R \) at the High-Luminosity LHC. Our results highlight the testability of the BLSM at current and future collider experiments, and provide a promising avenue for probing the origin of neutrino masses and the baryon asymmetry of the Universe.

    hep-phhep-exPRD(2026)·1 citation
11. 11*

    Exploring semi-relativistic $p$-wave dark matter annihilation in minimal Higgs portal near supermassive black hole

    Chih-Ting Lu🇨🇳 · Xiao-Yi Luo🇨🇳 · Zi-Qing Xia🇨🇳

    We conduct a comprehensive analysis of potential annihilation processes of light dark matter (DM) in minimal Higgs portal models near supermassive black hole (Sgr A${}^{\star }$) in the Galactic Center, considering interactions between DM particles mediated by either a light scalar or pseudoscalar with couplings $c_s$ and $c_p$. Accelerated by the supermassive black hole, DM particles can reach velocities up to half the speed of light, significantly enhancing the $p$-wave annihilation cross-section, allowing forbidden annihilation channels within specific mass ranges, and producing unique gamma-ray spectral signals. Utilizing gamma-ray observation from Fermi Large Area Telescope (Fermi-LAT) in the direction of Sgr $A^{\star }$, we constrain light DM parameter in the mass range of $0.3-10\text{GeV}$ . Our results indicate that the couplings $c_s$ and $c_p$ are constrained to the order of $10^{-5}$, corresponding to a DM annihilation cross-section as low as $10^{-38}$${\mathrm{cm}}^3/\mathrm{s}$. In the future, the Very Large Gamma-ray Space Telescope (VLAST), with a larger detection area and broader detection range from $1$ MeV to $1$ TeV, will enhance our ability to probe sub-GeV DM and offer the opportunity to further study the forbidden annihilation scenario.

    hep-phPRD(2025)·2 citations
12. 12*

    NNLO QCD corrections to unpolarized and polarized SIDIS

    Saurav Goyal🇮🇳 · Roman N. Lee🇷🇺 · Sven-Olaf Moch🇩🇪 · Vaibhav Pathak🇮🇳 · Narayan Rana🇮🇳 · V. Ravindran🇮🇳

    The semi-inclusive deep-inelastic scattering (SIDIS) process requires the presence of an identified hadron H${}^{\prime }$ in the final state, which arises from the scattering of a lepton with an initial hadron P. By employing factorization in quantum chromodynamics (QCD), SIDIS provides essential knowledge on the hadron structure, enabling the exploration of parton distribution functions (PDFs) and fragmentation functions (FFs). The coefficient functions for SIDIS can be calculated in perturbative QCD and are currently known to the next-to-next-to-leading order (NNLO) for the cases, where the incoming lepton and the hadron P are either both polarized or unpolarized. We present a detailed description of these NNLO computations, including a thorough discussion of all the partonic channels, the calculation of the amplitudes and master integrals for the phase-space integration as well as the renormalization of ultraviolet divergences and mass factorization of infrared divergences in dimensional regularization through NNLO. We provide an extensive phenomenological analysis of the effects of NNLO corrections on SIDIS cross sections for different PDFs and FFs and various kinematics, including those of the future Electron-Ion Collider (EIC). We find that these corrections are not only significant but also crucial for reducing the dependence on the renormalization and factorization scales ${\mu }_R$ and ${\mu }_F$ to obtain stable predictions.

    hep-phhep-exhep-thPRD(2025)·28 citations
13. 13*

    Nuclear matter properties from chiral-scale effective theory including a dilatonic scalar meson

    Lu-Qi Zhang🇨🇳 · Yao Ma🇨🇳 · Yong-Liang Ma🇨🇳

    Chiral effective theory has become a powerful tool for studying the low-energy properties of QCD. In this work, we apply an extended chiral effective theory -- chiral-scale effective theory -- including a dilatonic scalar meson to study nuclear matter and find that the properties around saturation density can be well reproduced. Compared to the traditionally used Walecka-type models in nuclear matter studies, our approach improves the behavior of symmetry energy and the incompressibility coefficient in describing empirical data without introducing additional freedoms. Moreover, the predicted neutron star structures fall within the constraints of GW170817, PSR J0740+6620, and PSR J0030+0451, while the maximum neutron star mass can reach about $3M_{\odot }$ with a pure hadronic phase. Additionally, we find that symmetry patterns of the effective theory significantly impact neutron star structures. %In chiral-scale effective theory, effective operators are well organized by chiral-scale orders and freedoms induced by QCD symmetry patterns. We believe that introducing this type of theory into nuclear matter studies can lead to a deeper understanding of QCD, nuclear matter, and compact astrophysical objects.

    ↳ nucl-thastro-ph.HEhep-phCPC(2026)·6 citations
14. 14*

    Inflationary observables in $F(R)$ gravity

    Enrique Diaz · Oscar Meza-Aldama

    We present phenomenological signatures for a modified gravity model f(R), constructed with linear, quadratic, cubic and quartic terms. The obtained signatures satisfy current phenomenological bounds reported by PLANCK and BICEP3. Furthermore, two of the model solutions ${\sigma }_1$ and ${\sigma }_2$ seem to favor a much lower value for the tensor-to-scalar ratio $0.0005<r_{{\sigma }_1}<0.0015$ and $r_{{\sigma }_2}<0.00015$ than the current reported experimental bounds. The results we obtained are quantitatively similar to those presented in previous studies for $R^3$ models.

    ↳ gr-qchep-ph0 citations
15. 15*

    Cosmological scenario based on the first and second laws of thermodynamics: Thermodynamic constraints on a generalized cosmological model

    Nobuyoshi Komatsu🇯🇵

    The first and second laws of thermodynamics should lead to a consistent scenario for discussing the cosmological constant problem. In the present study, to establish such a thermodynamic scenario, cosmological equations in a flat Friedmann-Lemaître-Robertson-Walker universe were derived from the first law, using an arbitrary entropy $S_H$ on a cosmological horizon. Then, the cosmological equations were formulated based on a general formulation that includes two extra driving terms, $f_{\Lambda }(t)$ and $h_{\text{B}}(t)$, which are usually used for, e.g., time-varying $\Lambda (t)$ cosmology and bulk viscous cosmology, respectively. In addition, thermodynamic constraints on the two terms are examined using the second law of thermodynamics, extending a previous analysis [Phys. Rev. D 99, 043523 (2019) (arXiv:1810.11138)]. It is found that a deviation $S_{\Delta }$ of $S_H$ from the Bekenstein-Hawking entropy plays important roles in the two terms. The second law should constrain the upper limits of $f_{\Lambda }(t)$ and $h_{\text{B}}(t)$ in our late Universe. The orders of the two terms are likely consistent with the order of the cosmological constant ${\Lambda }_{\text{obs}}$ measured by observations. In particular, when the deviation $S_{\Delta }$ is close to zero, $h_{\text{B}}(t)$ and $f_{\Lambda }(t)$ should reduce to zero and a constant value (consistent with the order of ${\Lambda }_{\text{obs}}$), respectively, as if a consistent and viable scenario could be obtained from thermodynamics.

    ↳ gr-qcastro-ph.COhep-phEPJC(2025)·2 citations
16. 16*

    Prospects for probing dark matter particles and primordial black holes with the Hongmeng mission using the 21 cm global spectrum at cosmic dawn

    Meng-Lin Zhao🇺🇸 · Sai Wang🇨🇳 · Xin Zhang🇺🇸

    Probing dark matter particles and primordial black holes remains a pivotal challenge in modern cosmology. Exotic energy injections from dark matter annihilation, decay, and PBH Hawking evaporation can alter the thermal and ionization histories of the early universe, leaving distinctive imprints on the 21 cm global spectrum. We assess the potential of the upcoming space project, the Hongmeng mission, to probe dark matter particles and PBHs using the 21 cm global spectrum. Under ideal conditions with 1000 hours of integration time and negligible foreground residuals, the Hongmeng project can reach sensitivities to dark matter annihilation cross sections and decay lifetimes to $⟨\sigma v⟩\sim 10^{-28}\mathrm{c}{\mathrm{m}}^3{\mathrm{s}}^{-1}$ and $\tau \sim 10^{28}\mathrm{s}$, respectively, for dark matter particles with a mass of $10\mathrm{GeV}$. It can also probe PBHs with masses of $10^{16}\mathrm{g}$ and abundances as low as $f_{\mathrm{PBH}}\simeq 10^{-6}$. These results indicate that the Hongmeng mission can improve current constraints on dark matter annihilation, decay, and PBH Hawking radiation by nearly two orders of magnitude. Moreover, the Hongmeng mission surpasses current limits on sub-GeV dark matter probing and enables the probing of Hawking radiation from PBHs with masses above $10^{17}\mathrm{g}$, which remain undetectable through conventional cosmological means. Overall, the upcoming Hongmeng project holds great promise for advancing the investigation of both dark matter and PBHs, potentially deepening our understanding of the nature of dark matter.

    ↳ astro-ph.COastro-ph.HEgr-qchep-phJCAP(2025)·12 citations
17. 17*

    Gravitational Waves from Post-Collision of Fuzzy Dark Matter Solitons

    Chen Tan🇨🇳 · Jing-Kang Bin🇨🇳 · Ke Wang🇨🇳

    According to the Schrödinger-Poisson (SP) equations, fuzzy dark matter (FDM) can form a stable equilibrium configuration, the so-called FDM soliton. The SP system can also determine the evolution of FDM solitons, such as head-on collision. In this paper, we first propose a new adimensional unit of length, time and mass. And then, we simulate the adimensional SP system with $\mathtt{PyUltraLight}$ to study the GWs from post-collision of FDM solitons when the linearized theory is valid and the GW back reaction on the evolution of FDM solitons is ignored. Finally, we find that the GWs from post-collisions have a frequency of (few ten-years)${}^{-1}$ or (few years)${}^{-1}$ when FDM mass is $m=10^{-18}\mathrm{eV}/{\mathrm{c}}^2$ or $m=10^{-17}\mathrm{eV}/{\mathrm{c}}^2$. Therefore, future detection of such GWs will constrain the property of FDM particle and solitons.

    ↳ astro-ph.COastro-ph.GAhep-ph1 citation
18. 18*

    Probing medium response via strangeness enhancement around quenched jets

    Ao Luo🇨🇳 · Shanshan Cao🇨🇳 · Guang-You Qin🇨🇳

    Jet-induced medium excitation is a crucial part of jet interactions with the quark-gluon plasma (QGP) in relativistic heavy-ion collisions, and has recently been confirmed by experiment for the first time. Based on the AMPT model simulation, we propose the strangeness enhancement around quenched jets as a novel signature of jet-induced medium excitation. By applying the jet-particle correlation techniques, we calculate jet-induced particle yields around the jets and find a significant enhancement of the strange-to-non-strange-hadron ratio and the double-to-single-strange-hadron ratio correlated with jets in relativistic nucleus-nucleus collisions relative to proton-proton collisions. This enhancement increases with both the strength of jet-QGP interactions and the radial distance from jet axis. These observations align with the features of jet-induced medium excitation and parton coalescence in hadron formation, and await experimental validation in the future measurements.

    ↳ nucl-thhep-phnucl-exPLB(2025)·3 citations
19. 19*

    GRB multi-TeV detection: Beyond standard physics?

    Giorgio Galanti🇮🇹 · Lara Nava🇮🇹 · Marco Roncadelli🇮🇹 · Fabrizio Tavecchio🇮🇹 · Giacomo Bonnoli🇮🇹

    The recent detection by LHAASO up to 18 TeV of the gamma ray burst GRB 221009A at redshift $z=0.151$ challenges standard physics because of the strong absorption due to the extragalactic background light (EBL) for photons with energies above 10 TeV. Emission models partially avoiding EBL absorption proposed to explain such an event are unsatisfactory since they require peculiar and contrived assumptions. By introducing in magnetized media the interaction of photons with axion-like particles (ALPs) - which are a generic prediction of most theories extending the standard model of particle physics towards a more satisfying theory - the detection of GRB 221009A can be naturally explained, thereby providing a strong hint at ALP existence.

    ↳ astro-ph.HEhep-ph1 citation
20. 20*

    Double Exponents in $SL(2,\mathbb{Z})$ Cosmology

    Renata Kallosh🇺🇸 · Andrei Linde🇺🇸

    Recently proposed $SL(2,\mathbb{Z})$ invariant $\alpha$-attractor models have plateau potentials with respect to the inflaton and axion fields. The slope of the potential in the inflaton direction is exponentially suppressed at large values of the inflaton field, but the slope of the potential in the axion direction is double-exponentially suppressed. Therefore, the axion field remains nearly massless and practically does not change during inflation. The inflationary trajectory in such models is stable with respect to quantum fluctuations of the axion field. We show that isocurvature perturbations do not feed into the curvature perturbations during inflation, and discuss the possibility of such transfer at the post-inflationary stage.

    ↳ hep-thastro-ph.COgr-qchep-phJCAP(2025)·14 citations
21. 21*

    Experimental search potential for sbottom via ${\tilde{\chi }}_1^{\pm }$ decays at the LHC Run-3 and HL-LHC, in final states with same-sign leptons and multiple jets

    Otilia Ducu🇷🇴

    This paper explores the experimental search potential for sbottom pair production in an R-parity conserving scenario at the LHC Run-3 and HL-LHC. The sbottom decays with a 100% BR via a chargino, ${\tilde{b}}_1\to t{\tilde{\chi }}_1^{\pm }$, which subsequently decays to a $W$ boson and a neutralino, ${\tilde{\chi }}_1^{\pm }\to W{\tilde{\chi }}_1^0$, also with a 100% BR. The study follows the ATLAS object definitions and event selection criteria from Ref. JHEP06(2020)046, focusing on Rpc2L1b and Rpc2L2b signal regions defined with same-sign leptons and at least one $b$-tagged jet. Projected exclusion limits are presented in the ${\tilde{b}}_1$ - ${\tilde{\chi }}_1^0$ mass plane for three center-of-mass energies (13 TeV, 13.6 TeV, and 14 TeV) and three integrated luminosity scenarios (139 fb${}^{-1}$, 300 fb${}^{-1}$, and 3000 fb${}^{-1}$). keywords: sbottom pair production, same-sign leptons, multi-leptons

    ↳ hep-exhep-phInt.J.Mod.Phys.A(2025)·1 citation
22. 22*

    Semi-Classical Spin Hydrodynamics in Flat and Curved Spacetime: Covariance, Linear Waves, and Bjorken Background

    Annamaria Chiarini🇩🇪 · Julia Sammet🇩🇪 · Masoud Shokri🇩🇪

    We explore various aspects of semi-classical spin hydrodynamics, where hydrodynamic currents are derived from an expansion in the reduced Planck constant $\hslash$, incorporating both flat and curved spacetimes. After establishing covariant definitions for angular momentum currents, we demonstrate that the conservation of the energy-momentum tensor requires modifications involving the Riemann curvature and the spin tensors. We also revise pseudo-gauge transformations to ensure their applicability in curved spacetimes. Key assumptions for semi-classical spin hydrodynamics are introduced, enabling studies without explicitly invoking quantum kinetic theory. We derive and analyze the linearized semi-classical spin hydrodynamic equations, proving that spin and fluid modes decouple in the linear regime. As a concrete example, we study the ideal-spin approximation in a dissipative fluid with shear viscosity. This analysis confirms our general result: the damping of spin waves is governed solely by spin relaxation time coefficients, independent of linear fluid perturbations. We also examine the Gibbs stability criterion and reveal its limitations at first order in $\hslash$, signaling the inherent anisotropy of the equilibrium state, which remains unaddressed in current semi-classical spin hydrodynamics formulations. Finally, within a conformal Bjorken flow background and using the slow-roll approximation attractor for the fluid sector, we show that the relaxation of the spin potential is governed by spin relaxation time coefficients, mirroring the damping behavior of spin waves in the linear regime.

    ↳ gr-qchep-phhep-thnucl-thPRD(2026)·10 citations
23. 23*

    Constituent Quark Model and nucleon-Nucleon Potentials

    Th. A. Rijken🇳🇱

    In these notes, while focusing on the meson-nucleon vertices, we give a derivation of the nucleon-nucleon 9NN) potentials from meson-exchange between quarks. To establish such a relation the quark-quark-meson (QQM) interactions are properly defined. Hitherto, the coefficients in the Pauli-spinor expansion of the meson-nucleon-nucleon (NNM) vertices are equated with those of the QQM-vertices. In these notes we employ the description of the nucleon with Dirac-spinors in the SU(6) semi-relativistic "constituent" quark-model (CQM) as formulated by LeYouanc, et al. It appears that the constituent quark model with $m_q=M_N/3$, is able to produce the same ratio's for the central-, spin-spin-, tensor-, spin-orbit-, and quadratic-spin-orbit Pauli-invariants as in the phenomenological NNM-vertices. In order to achieve this, the scalar-, magnetic-vector, and axial-vector interactions require, besides the standard ones, an extra coupling to the quarks without the introduction of new parameters. in the case of the axial-vector mesons an extra coupling to the quarks is necessary, which is related to the quark orbital angular momentum contribution to the nucleon spin. Furthermore, a momentum correlation between the quark that is coupled to the meson and the remaining quark pair, and a (gaussian) QQM form factor, are necessary to avoid "spurious" terms. From these results we have obtained a formulation of the QQ-interactions which is directly related to the NN extended-soft-core (ESC) interactions. This has been applied to mixed quark-nuclear matter in a study of (heavy) neutron stars.

    ↳ nucl-thhep-ph2 citations
24. 24*

    Moments from Momentum Derivatives in Lattice QCD

    Zhuoyi Pang🇨🇳 · Jian-Hui Zhang🇨🇳 · Dian-Jun Zhao🇨🇳

    We show that the traditional moments approach in lattice QCD, based on operator product expansion (OPE), can be realized in a way that utilizes derivatives in momentum rather than in distance. This also avoids power divergent mixings, and thus allows to extract moments order by order, to all orders in principle. Moreover, by exploiting the symmetry of lattice matrix elements,we can determine the even and odd moments separately. As a demonstrative example, we determine the first three moments beyond the tensor charge gT of the isovector quark transversity distribution in the nucleon.

    ↳ hep-lathep-phhep-thnucl-ex+1CPC(2025)·5 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.