Tue·Mar 18, 2025Tuesday·March 18, 2025

1. 01*

   NNPDFpol2.0: a global determination of polarised PDFs and their uncertainties at next-to-next-to-leading order

   Juan Cruz-Martinez🇨🇭 · Toon Hasenack🇳🇱 · Felix Hekhorn🇫🇮 · Giacomo Magni🇳🇱 · Emanuele R. Nocera🇮🇹 · Tanjona R. Rabemananjara🇳🇱 · Juan Rojo🇳🇱 · Tanishq Sharma🇮🇹 · Gijs van Seeventer🇳🇱

   We present NNPDFpol2.0, a new set of collinear helicity parton distribution functions (PDFs) of the proton based on legacy measurements of structure functions in inclusive neutral-current longitudinally polarised deep-inelastic scattering (DIS), and of W -boson, single-inclusive, and di-jet production asymmetries in longitudinally polarised proton-proton collisions. The determination is accurate to next-to-next-to-leading order in the strong coupling, and includes heavy quark mass corrections in the analysis of DIS data. Uncertainties due to missing higher-order corrections are systematically incorporated by means of a covariance matrix determined by scale variations. NNPDFpol2.0 is based on a machine learning methodology, that makes use of Monte Carlo sampling for the representation of uncertainties into PDFs, of a neural network for the parametrisation of PDFs, of stochastic gradient descent for the optimisation of PDF parameters, and of hyperoptimisation for the selection of the best fitting model. We study the impact on PDFs of higher-order corrections, of the positivity constraint, and of the data. We demonstrate two phenomenological applications of NNPDFpol2.0, specifically the determination of the proton spin fraction carried by gluons and quarks, and of theoretical predictions for single-hadron production in longitudinally polarised DIS and proton-proton collisions.

   hep-phhep-exnucl-exnucl-thJHEP(2025)·37 citations
2. 02*

   The $\varphi NN,J/\psi NN,{\eta }_{c}NN$ systems based on HAL QCD interactions

   Liang-Zhen Wen🇨🇳 · Yao Ma🇨🇳 · Lu Meng🇩🇪 · Shi-Lin Zhu🇨🇳

   We investigate the existence of bound states and resonances in the $\varphi NN,J/\psi NN,{\eta }_{c}NN$ systems using HAL QCD interactions for $\varphi N,J/\psi N$, and ${\eta }_{c}N$. We employ the Gaussian expansion method to solve the complex-scaled Schrödinger equation and find no resonances or bound states in the $J/\psi NN$ and ${\eta }_{c}NN$ systems. We estimate the interaction between charmonium and nuclei, concluding that the $J/\psi$ or ${\eta }_c$ is likely to bind with ${}^3\mathrm{H}$, ${}^3\mathrm{He}$, ${}^4\mathrm{He}$, and heavier nuclei. For the $\varphi NN$ system, the lattice QCD $\varphi N\left({}^2{S}_{1/2}\right)$ interaction is absent. We combine the $\varphi p$ correlation function analysis and HAL QCD results in Model A. We assume the spin-spin interactions for $J/\psi N$ and $\varphi N$ systems are inversely proportional to their masses in Model B. Model A predicts a stronger $\varphi N({}^2{S}_{1/2})$ interaction and permits a two-body bound state, whereas Model B suggests the interaction is attractive but too weak to form a bound state. Both models predict bound states for the $I(J^P)=0(0^{-})$ and $0(1^{-})$ $\varphi NN$ systems. In Model A, these states are deeply bound with binding energies exceeding 15 MeV and remain existent when considering parameter uncertainties. In contrast, these states are very loosely bound in Model B, with binding energies below 1 MeV and an existent probability of about 60\% when parameter uncertainties are considered. In both models, there exist very loosely bound $I(J^P)=0(2^{-})$ three-body states which resemble a $\varphi$-d atom with the $\varphi$ meson surrounding the deuteron, but their existences are sensitive to parameter uncertainties. No bound states or resonances are found in the isovector $I(J^P)=1(1^{-})$ $\varphi NN$ system.

   hep-phhep-exhep-latnucl-ex+1PRD(2025)·13 citations
3. 03*

   Tomography of the Rho meson in the QCD Instanton Vacuum: Transverse Momentum Dependent Parton Distribution Functions

   Wei-Yang Liu🇺🇸 · Ismail Zahed🇺🇸

   We analyse the rho meson unpolarized and polarized transverse momentum dependent parton distribution functions (TMDPDFs) in the instanton liquid model (ILM). The corresponding TMDs in ILM are approximated by a constituent quark beam function in the leading Fock state multiplied by a rapidity-dependent factor resulting from the staple-shaped Wilson lines, for fixed longitudinal momentum, transverse separation, and rapidity. At the resolution of the ILM, all of the rho meson TMDs are symmetric in parton x for fixed transverse momentum, and Gaussian-like in the transverse momentum for fixed parton x. The latter is a direct consequence of the profiling of the quark zero modes in the ILM. The evolved TMDs at higher rapidity using the Collins-Soper kernel, and higher resolution using the renormalization group (RG), show substantial skewness towards low parton x.

   hep-phhep-lathep-thnucl-thPRD(2025)·8 citations
4. 04*

   Fully-heavy tetraquarks in the vacuum and in a hot environment

   Vinícius S. Silva🇧🇷 · Cássio Pigozzo🇧🇷 · Luciano M. Abreu🇧🇷

   We study the thermal behavior of quarkonia and fully-heavy tetraquark states associated to the charmonium, bottomonium and bottom-charmonium mass spectra. The starting point is the Schrödinger formalism with a vacuum Cornell-like potential. The spin-spin, spin-orbit and tensor contributions are also considered to describe the structure of the vacuum quarkonia $Q\bar{Q}$ spectra ($Q$ denoting $c,b$ quarks). The parameters of the model are fixed using the experimental data of the $Q\bar{Q}$ states. After that, this formalism is extended to the fully-heavy tetraquark states within the $1^3{S}_1$ axial diquark--$1^3{S}_1$ axial antidiquark configuration $[QQ][\bar{Q}\bar{Q}]$, and their vacuum mass spectra are obtained and compared to the experimental data recently obtained. Our predictions support the interpretation of the $X(6600)$ (or $X(6552)$), $X(6900)$ and $X(7200)$ states as the radially-excited $T_{4c}(n^1{S}_0)$ configurations with $n=2,3,4$. In the sequence, we evaluate the mass spectra behavior in a thermal medium, by introducing a modified temperature-dependent Cornell potential. As a consequence, this formalism enables us to get some insight into the dissociation mechanism of $[QQ][\bar{Q}\bar{Q}]$ states caused by a thermal medium, and into the temperature range at which the tetraquark states might be formed. We find that these structures cannot be formed in the thermal medium when the system has a temperature higher than about twice the critical temperature. These findings may be useful to better understand the features of the exotics in heavy-ion collisions. [NOTE: version with inclusion of an Addendum incorporating the $2^{++}$ state predictions, motivated by the new CMS results [arXiv:2506.07944].]

   hep-phEPJC(2025)·3 citations
5. 05*

   Gluonic structure from instantons

   Christian Weiss🇺🇸

   The instanton vacuum provides an effective description of chiral symmetry breaking by local topological fluctuations of the gauge fields, as observed in lattice QCD simulations. The resulting effective dynamics at momenta below $1/\bar{\rho }\approx$ 0.6 GeV explains the basic features of light-quark correlation functions and is used extensively in studies of hadron structure. The instanton fields also make definite contributions to the gluonic structure of light hadrons, as expressed in the matrix elements of composite quark-gluon or gluon operators. The article reviews the gluonic structure of light hadrons (nucleon, pion) induced by instantons. This includes: (i) twist-2 parton distributions and momentum sum rule; (ii) twist-3 angular momentum and spin-orbit interactions; (iii) twist-3 and 4 quark-gluon correlations and power corrections; (iv) trace anomaly and hadron mass decomposition; (v) scalar gluon form factors and mechanical properties; (vi) axial anomaly and pseudoscalar gluon form factors. It also discusses possible further applications of the methods and recent developments including gauge field configurations beyond instantons.

   hep-phhep-latActa Phys.Polon.B(2025)·3 citations
6. 06*

   Investigation of the semileptonic decays ${\Xi }_b^{{(}^{\prime })}\to {\Xi }_c^{{(}^{\prime })}\ell {\bar{\nu }}_{\ell }$

   Z. Neishabouri🇮🇷 · K. Azizi🇮🇷

   We study the semileptonic decays of ${\Xi }_b^{{(}^{\prime })}\to {\Xi }_c^{{(}^{\prime })}\ell {\bar{\nu }}_{\ell }$ in all lepton channels. To do this, we first obtain the form factors defining these decay modes within the framework of QCD sum rules. Then, using the transferred momentum squared-dependent form factors, we compute the decay widths and branching fractions for all lepton channels and compare the results of our calculations with those obtained from other theoretical methods. We also estimate the branching ratios and the ratio of branching fractions at different leptonic channels to provide useful information for future experiments may be planned at different Colliders. Such comparison will provide valuable information about the consistency/inconsistency of the SM theory predictions with experimental data in weak semileptonic single heavy baryon decays.

   hep-phhep-exhep-latPRD(2025)·7 citations
7. 07*

   Newly observed $\kappa$(2600) and the highly excited states of the $K_0^{\ast }$ family

   Cheng-Qun Pang🇨🇳 · Hao Chen🇨🇳 · Yun-Hai Zhang🇨🇳

   We conducted a study using the modified Godfrey-Isgur quark model and quark pair creation model to investigate the spectrum and two-body strong decays of the newly discovered $\kappa$(2600) resonance by the LHCb collaboration. Our analysis revealed that this {resonance} can be assigned as the fourth radial excitation within the $0^{+}$ light strange meson family. Furthermore, we predicted additional radial excitations in this meson family and systematically discussed their spectra, decay behaviors, and branching ratios. These results provide critical guidance for future to identify their signatures in experiments.

   hep-phPRD(2025)·5 citations
8. 08*

   Semileptonic decays of ${\Lambda }_c^{+}$ in light-front quark model with nonvalence contributions

   Chong-Chung Lih🇨🇳 · Chao-Qiang Geng🇨🇳

   We investigate the exclusive semilpetonic decays of ${\Lambda }_c^{+}\to (\Lambda /n){\ell }^{+}{\nu }_{\ell }(\ell =e,\mu )$ within the standard model by using the light-front quark model (LFQM). The form factor behaviors are obtained from the effective treatment of nonvalence contributions in addition to the valence ones in the Drell-Yan-West frame due to the Bethe-Salpeter formalism. Based on these form factors, we find that the decay branching ratios of ${\Lambda }_c^{+}\to (\Lambda e^{+}{\nu }_e,\Lambda {\mu }^{+}{\nu }_e,n{e}^{+}{\nu }_e,n{\mu }^{+}{\nu }_e)$ are about $(3.39,3.21,0.36,0.35)\%$ with the non-valence contributions, which are consistent with the recent experimental measurements at BESIII. Furthermore, we use the experimental data to fit the $\beta$ parameters in the baryonic distribution amplitudes under the LFQM, resulting in (${\beta }_{{\Lambda }_c},{\beta }_{\Lambda },{\beta }_n)=(0.58\pm 0.08,0.52\pm 0.08,0.44\pm 0.04)$.

   hep-phhep-exhep-th0 citations
9. 09*

   $B\to TT$ decays in the QCD factorization approach

   Ya-Bing Zuo🇨🇳 · Jia-Yu Zou🇨🇳 · Shi-Yu Liang🇨🇳 · Ming-Ge Li🇨🇳 · Shan-Shan Hu🇨🇳

   In this study, the nonleptonic two-body $B$ decays into two tensor mesons (including $a_2(1320)$, $K_2^{\ast }(1430)$, $f_2(1270)$, $f_2^{\prime }(1525)$, denoted generically as $T$) are investigated in the QCD factorization approach. The branching ratios, longitudinal polarization fractions, and CP asymmetries are predicted systematically. It is found that, from the perspective of central values, the branching ratios for the decays $B\to \{a_2{f}_2^{\prime },f_2{f}_2^{\prime }\}$, $\{a_2{f}_2,f_2{f}_2\}$ and $\{f_2{K}_2^{\ast },K_2^{\ast }{f}_2^{\prime }\}$ are at the order of $10^{-8}$, $10^{-7}$ and $10^{-6}$, respectively. The branching ratios for the decays into $\{a_2{a}_2,K_2^{\ast }{K}_2^{\ast }\}$ and $a_2{K}_2^{\ast }$ are at the order of $10^{-8}-10^{-7}$ and $10^{-7}-10^{-6}$, respectively. The longitudinal polarization fractions are approximately $0.7-1$. Especially, for the ${\bar{B}}^0/B^0\to \{K_2^{\ast -}{K}_2^{\ast +},f_2^{\prime }{f}_2^{\prime }\}$ decays, the longitudinal polarization fractions are equal to $1$. The CP asymmetry for the $B^{\pm }\to a_2^{\pm }{f}_2$ modes is most significant, roughly $-22\%$. The CP asymmetries for the decays $B\to \{a_2{f}_2^{\prime },f_2{f}_2^{\prime },f_2^{\prime }{f}_2^{\prime }\}$ and ${\bar{B}}^0/B^0\to K_2^{\ast -}{K}_2^{\ast +}$ are equal to zero. Our results may be tested by more precise experiments in the future.

   hep-ph0 citations
10. 10*

    Family Unification in a Six Dimensional Theory with an Orthogonal Gauge Group

    Nobuhito Maru🇯🇵 · Ryujiro Nago🇯🇵

    We propose a simple model of family unification, which is a six dimensional $SO(20)$ gauge theory with a single fermion in the spinorial representation. After compactification to five dimensions, our model gives a five dimensional model where the Standard Model Higgs field is unified into the fifth component of the five dimensional gauge field as well as three generations of quarks and leptons are unified into a single spinor field.

    hep-phhep-thPTEP(2026)·0 citations
11. 11*

    Dark Spin-2 Field Solitons as a Source of Electromagnetic Radiation

    Enrico D. Schiappacasse🇨🇱

    Spin-$s$ light dark boson particles can exhibit wave-like behavior, capable of forming long-lived, coherent, spatially localized structures known as solitons. This work considers the possibility that a light spin-2 particle might be part of or all the dark matter content of the Universe, which could result in a significant fraction of solitons existing today in galactic halos. If these dark matter particles interact with electromagnetism through dimension-6 operators, the solitons may experience parametric resonance of photons triggered by the surrounding electromagnetic field. We explore the feasibility and key characteristics of this electromagnetic radiation, as well as the potential for detection through soliton mergers using ground-based facilities.

    hep-phastro-ph.COastro-ph.HEJCAP(2025)·7 citations
12. 12*

    Gluon gravitational form factors of the proton in a light-front spectator model

    Amrita Sain🇨🇳 · Poonam Choudhary🇮🇳 · Bheemsehan Gurjar🇮🇳 · Chandan Mondal🇨🇳 · Dipankar Chakrabarti🇮🇳 · Asmita Mukherjee🇮🇳

    We calculate the gluon gravitational form factors (GFFs) of the proton using a light-front spectator model based on soft-wall AdS/QCD, where the active parton is a gluon. The model parameters are determined by fitting the unpolarized gluon distribution function to the NNPDF3.0nlo dataset. Subsequently, we predict the polarized gluon distribution, finding consistency with global analyses. Our predictions for the gluon GFFs show good agreement with recent lattice QCD simulations and experimental extractions. Using these gluon GFFs, we compute the contribution of the gluon to the proton mass and mechanical radii. We also analyze the gluonic contribution to the two-dimensional Galilean densities, including energy density, radial and tangential pressure, isotropic pressure, and pressure anisotropy of the proton.

    hep-phhep-lathep-thnucl-thPRD(2025)·20 citations
13. 13*

    Nonholomorphic $A_4$ modular invariance for fermion masses and mixing in SU(5) GUT

    Mohamed Amin Loualidi🇦🇪 · Mohamed Miskaoui🇲🇦 · Salah Nasri🇦🇪

    Addressing the fermion flavor structures using modular invariance is a challenging task in the framework of quark-lepton unification. Building on recent applications of modular symmetry in non-supersymmetric models, we propose the first renormalizable $SU(5)$ grand unified theory incorporating level 3 nonholomorphic modular symmetry, ${\Gamma }_3\simeq A_4$. This framework constrains Yukawa couplings to polyharmonic Maaß forms, significantly reducing the number of free parameters while enhancing the predictive power of the models. We present a comprehensive analysis of fermion masses and mixing while tackling key GUT queries such as gauge coupling unification and proton decay. Beyond the minimal $SU(5)$ framework, the Higgs sector incorporates the $45_H$ dimensional Higgs field crucial in differentiating the masses of down quarks and charged leptons, and the fermion sector is extended with three right-handed neutrinos enabling neutrino masses via the type-I seesaw mechanism. We analyze two benchmark models with distinct modular weight and $A_4$ charge assignments. The predicted effective Majorana mass $m_{\beta \beta }$ values align with current neutrinoless double-beta decay experiments, and the effective neutrino mass $m_{\beta }$ is within the reach of future beta decay searches. The predicted sum of neutrino masses, $\sum m_i$, satisfies the upper bound set by recent cosmological observations. The gauge coupling unification is achieved through a light scalar triplet ${\varphi }_3\sim (3,3,-1/3)$ and a scalar octet ${\varphi }_5\sim (8,2,1/2)$ belonging to the $45_H$ Higgs, while proton decay constraints require a highly suppressed Yukawa couplings.

    hep-phPRD(2025)·19 citations
14. 14*

    Does finetuning make $D$-term contributions smaller in natural grand unified theories with spontaneous supersymmetry breaking?

    Nobuhiro Maekawa🇯🇵 · Taiju Tanii🇯🇵

    In this paper, we explore the natural grand unified theory (GUT) with spontaneous supersymmetry (SUSY) breaking, focusing on the contribution to sfermion and Higgs masses. Natural GUTs solve various problems in SUSY GUTs with the natural assumption that all terms allowed by $SO(10)\times U(1{)}_A$ symmetry are introduced with $O(1)$ coefficients. %, solve various the problems in SUSY GUTs. It is also possible to introduce spontaneous SUSY breaking in the natural GUT. This scenario predicts $D$-term contribution to sfermion and Higgs masses dominates the $F$-term contribution, that potentially leads to the SUSY flavor problem. Fortunately, it also predicts high-scale SUSY, which avoids the SUSY flavor problem but leads to the instability of the %need for fine-tuning to obtain the electroweak scale. The $D$-term domination results in the superheavy Higgsino unless the $D$-term contribution becomes comparable with the $F$-term contribution. We discuss whether it is possible to suppress the $D$-term contribution while maintaining the $F$-term contribution through the tuning of $O(1)$ coefficients in the natural GUT with spontaneous SUSY breaking. Our results indicate that it is impossible. %the D-term is proportional to the F-term and its derivatives, making it difficult to suppress the D-term independently. This also suggests that the mass spectrum of the sfermions can be predicted by the $D$-term contributions, and that the Higgsino is not a candidate for dark matter in the scenario.

    hep-phPRD(2025)·0 citations
15. 15*

    Exploring Physics beyond the Standard Model with Neutrinos

    Rukmani Mohanta🇮🇳

    Neutrinos, being elusive subatomic particles having only weak interactions, provide an ideal platform to look for physics beyond the Standard Model. In the present era of neutrino physics, various experiments are focusing towards the precision measurements of the oscillation parameters. Hence, various new physics scenarios which can affect the neutrino oscillation probabilities in matter, be in need of careful investigation. There is a slight tension at the level of $2\sigma$ between the recently reported results on the CP violating phase ${\delta }_{CP}$ by NOvA and T2K experiments, which can be attributed to the role of non-standard interactions (NSIs) in the propagation of neutrinos through matter. Another interesting possibility is that though neutrinos are electrically neutral, they can possess electromagnetic properties such as electric and magnetic dipole moments in the presence of new physics, and the neutrino oscillation experiments can put limits on them. In this work, we will focus on these two aspects and show how they can be used to probe the nature of new physics from model-building perspectives.

    hep-ph1 citation
16. 16*

    RelExt: A New Dark Matter Tool for the Exploration of Dark Matter Models

    Rodrigo Capucha🇵🇹 · Karim Elyaouti🇩🇪 · Milada Margarete Mühlleitner🇩🇪 · Johann Plotnikov🇩🇪 · Rui Santos🇵🇹

    We present the C++ program RelExt for Standard Model (SM) extensions that feature a Dark Matter (DM) candidate. The tool allows to efficiently scan the parameter spaces of these models to find parameter combinations that lead to relic density values which are compatible with the measured value within the uncertainty specified by the user. The code computes the relic density for freeze-out (co-)annihilation processes. The user can choose between several pre-installed models or any arbitrary other model featuring a discrete ${\mathbb{Z}}_2$ symmetry, by solely providing the corresponding FeynRules model files. The code automatically generates the required (co-)annihilation amplitudes and thermally averaged cross sections, including the total widths in the $s$-channel mediators, and solves the Boltzmann equation to determine the relic density. It can easily be linked to other tools like e.g.~ScannerS to check for the relevant theoretical and experimental constraints, or to BSMPT to investigate the phase history of the model and possibly related gravitational waves signals.

    hep-phComput.Phys.Commun.(2026)·5 citations
17. 17*

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

    Mayengbam Kishan Singh🇮🇳 · N. Nimai Singh🇮🇳

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

    hep-phJ.Subatomic Part.Cosmol.(2025)·0 citations
18. 18*

    Combined study of the isospin-violating decay $D_s^{\ast }\to D_s{\pi }^0$ and radiative decay $D_s^{\ast }\to D_s\gamma$ with intermediate meson loops

    Jun Wang🇨🇳 · Qiang Zhao🇨🇳

    We carry out a combined study of the isospin-violating decay $D_s^{\ast }\to D_s{\pi }^0$ and radiative decay $D_s^{\ast }\to D_s\gamma$ in an effective Lagrangian approach by taking into account the corrections from the one-loop transitions. By distinguishing the transition mechanisms of the long-distance interactions through the intermediate meson loops from the short-distance interactions through the $\eta -{\pi }^0$ mixing at the tree level the isospin-violating decay $D_s^{\ast }\to D_s{\pi }^0$ can be well constrained. In our approach the higher order corrections to the isospin-violating effects can involve the intermediate $D^{(\ast )}$ and $K^{(\ast )}$ scatterings. We find that the contributions from the destructive interference of intermediate meson loops via $D^{(\ast )0}(c\bar{u})K^{(\ast )+}(u\bar{s})$ and $D^{(\ast )+}(c\bar{d})K^{(\ast )0}(d\bar{s})$ rescatterings are significant. Within the commonly accepted ultra-violet (UV) cutoff range we obtain the partial decay width $\Gamma [D_s^{\ast }\to D_s{\pi }^0]=9.92_{-0.66}^{+0.76}\mathrm{eV}$. This approach allows us to describe the $D_s^{\ast }$ radiative decay in the same framework via the vector meson dominance (VMD) model. We demonstrate that both the tree-level and one-loop transitions can be self-consistently determined if we adopt the experimental data for the branching ratio fraction of $D_s^{\ast }\to D_s{\pi }^0$ to $D_s^{\ast }\to D_s\gamma$. It then leads to a reliable estimate of the total decay width of $D_s^{\ast }$, i.e. ${\Gamma }_{\text{total}}(D_s^{\ast +})=170_{-12}^{+13}\mathrm{eV}$.

    hep-phhep-exPRD(2025)·5 citations
19. 19*

    Quantifying the degree of hydrodynamic behaviour in heavy-ion collisions

    Sören Schlichting🇩🇪 · Clemens Werthmann🇩🇪

    Exploiting the first measurements of the same ion species in O+O collisons at RHIC and LHC, we propose an experimentally accessible observable to distinguish whether collective behaviour builds up through a hydrodynamic expansion of a strongly interacting QGP or through few rescatterings in a non-equilibrated dilute medium. Our procedure allows to disentangle the effects of the initial state geometry and the dynamical response mechanism on the total resulting anisotropic flow. We validate the ability of our proposed observable to discriminate between systems with different interaction rates using results from event-by-event simulations in kinetic theory in the Relaxation Time Approximation (RTA). As a proof of concept, we extract the degree of hydrodynamization for Pb+Pb collisions at LHC from experimental data.

    hep-phEPJ Web Conf.(2025)·0 citations
20. 20*

    D-shell mixing in light baryons and its effect on the orbital motion

    Nicholas Miesch🇺🇸 · Edward Shuryak🇺🇸 · Ismail Zahed🇺🇸

    The standard description of the nucleon in the non-relativistic quark model is an $1S,L=0$ state without orbital motion. Yet, there are several indications from phenomenology that an admixture of states with nonzero orbital motion maybe substantial. In this paper we focus on the ``second shell" of the nucleon excitations (D-shell), for which we give a modern description of the wave functions. We follow it by investigating what we call a ``maximal mixing" scenario, assuming a hypothetical long-range tensor force. We give the explicit wave functions for all states, before and after mixing, and re-assess many predictions such as the magnetic moments, the standard and transitional form-factors from the nucleon to $N^{\ast }$. Unexpectedly, in this scenario we can reproduce the long-puzzling features of the Roper resonance $N^{\ast }(1440)$. But even in this extreme case, the admixture of the $1D,L=2$ state to a nucleon remains significantly smaller than expected from phenomenology.

    hep-phPRD(2025)·2 citations
21. 21*

    Radiative corrections on vortical spin polarization in hot QCD matter

    Shuo Fang🇨🇳 · Shi Pu🇨🇳 · Di-Lun Yang🇹🇼

    We investigate the radiative corrections on spin polarization of relativistic fermions induced by vortical fields in thermal-equilibrium QCD matter at weak coupling. Such corrections stem from the self-energy gradients in quantum kinetic theory, which are further obtained by a more systematic and general approach through the Keldysh equation. By applying the hard-thermal-loop approximation, we obtain new corrections upon the spin-polarization spectrum and also the axial-charge current in connection to the axial/chiral vortical effect for massive quarks up to the leading order of the QCD coupling. Further influence on spin alignment of vector mesons from similar effects is also analyzed.

    hep-phhep-thnucl-thPRD(2025)·6 citations
22. 22*

    Isospin sum rules for bottom-baryon weak decays

    Wei-Chen Fu🇨🇳 · Si-Jia Wen🇨🇳 · Di Wang🇨🇳

    Isospin symmetry, as the most precise flavor symmetry, can be used to extract information about hadronic dynamics. The effective Hamiltonian operators of bottom quark weak decays are zero under a series of isospin lowering operators $I_{-}^n$, which permits us to generate isospin sum rules without the Wigner-Eckart invariants. In this work, we derive hundreds of isospin sum rules for the two- and three-body non-leptonic decays of bottom baryons. They provide hints for new decay modes and the isospin partners of pentaquark states.

    hep-phnucl-thEPJC(2025)·3 citations
23. 23*

    Towards a Robust Exclusion of the Sterile-Neutrino Explanation of Short-Baseline Anomalies

    Ohana Benevides Rodrigues🇺🇸 · Matheus Hostert🇺🇸 · Kevin J. Kelly🇺🇸 · Bryce Littlejohn🇺🇸 · Pedro A. N. Machado🇺🇸 · Ibrahim Safa🇺🇸 · Tao Zhou🇺🇸

    The sterile neutrino interpretation of the LSND and MiniBooNE neutrino anomalies is currently being tested at three Liquid Argon detectors: MicroBooNE, SBND, and ICARUS. It has been argued that a degeneracy between ${\nu }_{\mu }\to {\nu }_e$ and ${\nu }_e\to {\nu }_e$ oscillations significantly degrades their sensitivity to sterile neutrinos. Through an independent study, we show two methods to eliminate this concern. First, we resolve this degeneracy by including external constraints on ${\nu }_e$ disappearance from the PROSPECT reactor experiment. Second, by properly analyzing the full three-dimensional parameter space, we demonstrate that the stronger-than-sensitivity exclusion from MicroBooNE alone already covers the entire 2$\sigma$ preferred regions of MiniBooNE at the level of $2-3\sigma$. We show that upcoming searches at SBND and ICARUS can improve on this beyond the $4\sigma$ level, thereby providing a rigorous test of short-baseline anomalies.

    hep-phhep-exPRL(2025)·5 citations
24. 24*

    Finite-temperature bubble nucleation with shifting scale hierarchies

    Maciej Kierkla🇵🇱 · Philipp Schicho🇨🇭 · Bogumila Swiezewska🇵🇱 · Tuomas V. I. Tenkanen🇫🇮 · Jorinde van de Vis🇨🇭

    Focusing on supercooled phase transitions in models with classical scale symmetry, we formulate a state-of-the art framework for computing the bubble-nucleation rate, accounting for the presence of various energy scales. In particular, we examine the limitations of derivative expansions in constructing a thermal effective field theory for bubble nucleation. We show that for gauge field fluctuations, derivative expansions diverge after the leading two orders due to the strong variation in gauge field masses between the high- and low-temperature phases. By directly computing these contributions using the fluctuation determinant, we capture these effects while also accounting for large explicit logarithms at two loops, utilising the exact renormalisation group structure of the EFT. Finally, we demonstrate how this approach significantly improves nucleation rate calculations compared to leading-order results, providing a more robust framework for predicting gravitational-wave signals from supercooled phase transitions in models such as the SU(2)cSM.

    hep-phastro-ph.COhep-thJHEP(2025)·38 citations
25. 25*

    Direct Detection of Fast-Moving Low-Mass Dark Matter

    Haider Alhazmi🇸🇦 · Doojin Kim🇺🇸 · Kyoungchul Kong🇺🇸 · Gopolang Mohlabeng🇺🇸 · Jong-Chul Park🇰🇷 · Seodong Shin🇰🇷

    We examine the signals produced by dark matter interactions with electrons, which play a crucial role in direct detection experiments employing heavy target materials, particularly in many well-motivated sub-GeV dark matter scenarios. When the momentum transfer to target electrons is comparable to or exceeds their binding energy, atomic effects related to electron ionization become essential for accurately determining signal rates - especially in the case of fast-moving dark matter. In this paper, we revisit and extend the atomic ionization formalism, systematically comparing different approaches used to formulate the ionization form factor and identifying their respective domains of validity. As practical applications, we explore detection prospects in xenon target experiments. To illustrate our findings, we consider a specific scenario involving boosted dark matter, which often leads to high-momentum electron recoils. Our analysis demonstrates that the choice of formalism can significantly influence the interpretation of experimental data, depending on the regions of parameter space.

    hep-phPRD(2025)·9 citations
26. 26*

    Dissecting Jet Modification in the QGP with Multi-Point Energy Correlators

    João Barata🇨🇭 · Ian Moult🇺🇸 · Andrey V. Sadofyev🇵🇹 · João M. Silva🇵🇹

    Energy correlators have recently attracted significant attention in the study of heavy ion collisions due to their potential to robustly connect experimental measurements with an underlying quantum field theoretic description. While theoretical studies have so far primarily focused on the simplest two-point correlator, mapping out the dynamics of the quark-gluon plasma (QGP) will require developing a theoretical understanding of multi-point energy correlators. In this paper we present a systematic theoretical study of multi-point energy correlators for jets fragmenting in a dense quark-gluon plasma, accounting for both the medium's perturbative modification to the jet, and its hydrodynamical back-reaction. We consider both the scaling behavior of projected correlators, as well as the shape dependent three-point correlator, highlighting how both provide insight into interactions with the QGP. We discuss the parametric dependence of modifications on the medium scales, opening new opportunities to experimentally separate jet modifications from the medium response. Our results open the door to a systematic exploration of multi-point energy correlators in heavy ion collisions.

    hep-phnucl-thPRL(2026)·32 citations
27. 27*

    Supernova Gamma-Ray Constraints from Heavy Sterile Neutrino Decays

    Garv Chauhan🇺🇸 · R. Andrew Gustafson🇺🇸 · Ian M. Shoemaker🇺🇸

    Heavy sterile neutrinos can be produced in core-collapse supernovae (CCSNe), which are superb particle generators because of their high densities and temperatures. If the sterile neutrinos are long-lived, these may be produced inside the supernova core and escape the stellar envelope, later decaying into SM particles like photons and neutrinos. In this work, we first improve the calculation of the $\gamma$-ray fluxes. We then revisit the bounds on the sterile neutrino parameter space from the non-observation of $\gamma$-rays from SN1987A by the Solar Maximum Mission (SMM) and constraints from the diffuse $\gamma$-ray background arising from sterile neutrino decays. We find that the constraints arising from both the SMM data and the diffuse $\gamma$-ray background are weaker than those that have previously appeared in the literature. Finally, we study the sensitivity of several present and near-future $\gamma$-ray telescopes such as e-ASTROGAM and Fermi-LAT, assuming a nearby future galactic CCSN. We show that future observations can probe mixing angles as low as $|U_{\tau /\mu 4}{|}^2\sim 5\times 10^{-17}$.

    hep-phastro-ph.HEJCAP(2025)·7 citations
28. 28*

    Efficient Truncations of SU($N_c$) Lattice Gauge Theory for Quantum Simulation

    Anthony N. Ciavarella🇺🇸 · I. M. Burbano🇺🇸 · Christian W. Bauer🇺🇸

    Quantum simulations of lattice gauge theories offer the potential to directly study the non-perturbative dynamics of quantum chromodynamics, but naive analyses suggest that they require large computational resources. Large $N_c$ expansions are performed to order 1/$N_c$ to simplify the Hamiltonian of pure SU($N_c$) lattice gauge theories. A reformulation of the electric basis is introduced with a truncation strategy based on the construction of local Krylov subspaces with plaquette operators. Numerical simulations show that these truncated Hamiltonians are consistent with traditional lattice calculations at relatively small couplings. It is shown that the computational resources required for quantum simulation of time evolution generated by these Hamiltonians is 17-19 orders of magnitude smaller than previous approaches.

    ↳ hep-lathep-phquant-phPRD(2025)·32 citations
29. 29*

    Ultra-high frequency spikes of relic gravitons

    Massimo Giovannini🇨🇭

    The maximal frequency domain of the cosmic gravitons falls in the THz region where, without conflicting with the existing phenomenological bounds, only few particles with opposite (comoving) three-momenta are produced. Although any reliable scrutiny of the ultra-high frequency spikes should include all the sources of late-time suppression at lower and intermediate frequencies, some relevant properties of the averaged multiplicities and of the spectral energy density can be derived within a reduced set of approximations that may become invalid as the frequency decreases well below the Hz. The accuracy of these concurrent approaches is assessed from the properties of the transition matrix that relates the late-time spectra to the values of the mode functions during an inflationary stage. In the obtained framework the bounds on the post-inflationary expansion rate are swiftly deduced and compare quite well with the ones including a more faithful numerical treatment. It also follows that the timeline of the post-inflationary expansion rate might be observationally accessible, in the years to come, provided the electromechanical detectors (like microwave cavities or waveguides) operating between the MHz and the THz shall eventually reach sensitivities in the chirp amplitudes which are (at least) twelve orders of magnitude smaller than the ones experimentally attainable in the audio band (i.e. between few Hz and the kHz).

    ↳ gr-qcastro-ph.COhep-phhep-thClass.Quant.Grav.(2025)·5 citations
30. 30*

    Extracting the distribution amplitude of pseudoscalar mesons using the HOPE method

    S.-P. Alex Chang🇹🇼 · William Detmold🇺🇸 · Anthony V. Grebe🇺🇸 · Issaku Kanamori🇯🇵 · C.-J. David Lin🇹🇼 · Robert J. Perry🇺🇸 · Yong Zhao🇺🇸

    The pseudoscalar meson light-cone distribution amplitudes (LCDAs) are essential non-perturbative inputs for a range of high-energy exclusive processes in quantum chromodynamics. In this proceedings, progress towards a determination of the low Mellin moments of the pion and kaon LCDAs by the HOPE Collaboration is reported.

    ↳ hep-lathep-phPoS(2025)·1 citation
31. 31*

    Axion-Like Particle Mediated Dark Matter and Neutron Star Properties in the QHD Model

    Tanech Klangburam🇹🇭 · Chakrit Pongkitivanichkul🇹🇭

    We investigate the effects of the ALP-mediated dark matter (DM) model on neutron star properties using the Quantum Hadrodynamics model (QHD). Using the relativistic mean-field approximation with the QHD-ALP-DM framework, we compute the equation of state (EoS) of neutron stars. Based on our previous study, we find that typical ALP parameter values have no significant effect on the EoS. We then explore various parametrizations of this model by varying the DM Fermi momentum, $q_f$, and DM mass, $m_{\chi }$. Our results show that increasing $q_f$ or $m_{\chi }$ shifts the energy density to higher values while reducing the maximum mass, radius, and tidal deformability of neutron stars. Finally, comparison with observational constraints from gravitational wave events and pulsar measurements indicates that the allowed parameter space for this model is constrained to $q_f<0.05$ GeV and $m_{\chi }<1000$ GeV. As a result, our study highlights the importance of next-generation gamma-ray observatories, such as the Cherenkov Telescope Array (CTA), in probing the ALP-mediated DM model.

    ↳ astro-ph.HEhep-phnucl-thPRD(2025)·4 citations
32. 32*

    Effect of transverse momentum conservation and flow on symmetric cumulants $s{c}_{2,3}\left\{4\right\}$ and $s{c}_{2,3,4}\left\{6\right\}$

    Jia-Lin Pei🇨🇳 · Guo-Liang Ma🇨🇳 · Adam Bzdak🇵🇱

    Symmetric cumulants can improve our understanding of the joint probability distribution function $P\left(v_m,v_n,v_k,\dots ,{\Psi }_m,{\Psi }_n,{\Psi }_k,\dots \right)$, potentially offering new insights into the nature of the fluctuations of the quark-gluon plasma produced in relativistic heavy-ion collisions. In this work, the four-particle symmetric cumulants $s{c}_{2,3}\left\{4\right\}$, six-particle symmetric cumulants $s{c}_{2,3,4}\left\{6\right\}$, and the normalized cumulants $ns{c}_{2,3}\left\{4\right\}$ and $ns{c}_{2,3,4}\left\{6\right\}$ originating from transverse momentum conservation, collective flow, and the interplay between the two effects are calculated. Our results on $s{c}_{2,3}\left\{4\right\}$ are consistent with the ATLAS data using the subevent cumulant method, facilitating a more profound understanding of the origins of the symmetric cumulant in small systems. Our results on $s{c}_{2,3,4}\left\{6\right\}$ serve as theoretical predictions for future experimental measurements in small systems.

    ↳ nucl-thhep-phnucl-exPRC(2025)·3 citations
33. 33*

    Decoherence from quantum spacetime noise: An open-systems framework with application to neutrino oscillations

    Partha Nandi🇿🇦 · Tiasha Bhattacharyya🇮🇳 · A. S. Majumdar🇮🇳 · Graeme Pleasance🇿🇦 · Francesco Petruccione🇿🇦

    We present a general open-quantum-systems framework to model decoherence induced by stochastic Planck-scale fluctuations of spacetime, focusing on the kappa-Minkowski noncommutative geometry as a representative quantum-gravity scenario. Treating the deformation parameter as Gaussian white noise, we derive a Lindblad-type master equation applicable to arbitrary quantum systems and obtain a distinctive inverse-energy scaling of the decoherence rate, Gamma proportional to E^{-4}. As an illustrative example, we analyze a three-level system motivated by neutrino flavor oscillations and derive closed-form expressions for survival and transition probabilities with spacetime-induced damping. The E^{-4} scaling contrasts sharply with the positive power laws often invoked in quantum-gravity phenomenology and predicts negligible decoherence for high-energy neutrinos consistent with IceCube observations, while implying that the strongest effects arise in the extreme low-energy regime. In this context, the sub-eV-scale energies characteristic of the cosmic neutrino background provide a natural infrared benchmark for illustrating the enhanced sensitivity to quantum-spacetime fluctuations. Our results establish a unified formalism connecting quantum-information methods, open-system dynamics, and quantum-spacetime phenomenology, thereby offering a framework for exploring potential signatures of Planck-scale physics in future low-energy neutrino studies.

    ↳ hep-thgr-qchep-phquant-phPRResearch(2026)·12 citations
34. 34*

    Constraining the parameters of heavy dark matter and memory-burdened primordial black holes with DAMPE electron measurements

    Tian-Ci Liu🇨🇳 · Ben-Yang Zhu🇨🇳 · Yun-Feng Liang🇨🇳 · Xiao-Song Hu🇨🇳 · En-Wei Liang🇨🇳

    The DArk Matter Particle Explorer (DAMPE) is a space-based instrument for detecting GeV-TeV cosmic rays and gamma rays. High-energy cosmic rays could be emitted from several dark matter candidates theoretically, such as the heavy dark matter (HDM) and the primordial black holes (PBHs). HDM particles with a mass of $>100\mathrm{TeV}$ could decay into $\gtrsim 10\mathrm{TeV}$ electron/positron pairs. PBHs with a mass of $\lesssim 10^{10}\mathrm{g}$ would survive to the present day if the Hawking radiation is significantly suppressed due to the memory burden effect and can also lead to the emission of $\gtrsim 10\mathrm{TeV}$ electrons. In this work, we use the DAMPE electron measurements to obtain the constraints on the decay lifetime $\tau$ of HDM and the entropy index $k$ of memory-burdened PBHs at $95\%$ confidence level. The constraints on the fraction $f_{\mathrm{PBH}}$ are also derived with a fixed $k$. Furthermore, the high-energy tail of the DAMPE electron spectrum shows a sign of going upwards, possibly suggesting the presence of an additional component; we discuss if this spectral behavior is real, which parameter space is required for it to be attributed to HDM or PBH. We will show that the required parameters have been constrained by existing limits.

    ↳ astro-ph.HEhep-phJHEAp(2025)·16 citations
35. 35*

    Spectral properties and spin alignment of $\varphi$ meson in QCD Matter

    Zhong-Yuan Sun🇨🇳 · You-Yu Li🇨🇳 · Shuai Y. F. Liu🇨🇳

    As the spin alignment of a vector meson is predicted to be correlated with its spectral properties, we study the spectral properties of the $\varphi$ meson using two microscopic Lagrangians based either on chiral effective field theory or the quark-meson model. We calculate the self-energies and spectral functions of the $\varphi$ meson for these two Lagrangians at the one-loop level within the Matsubara formalism of finite-temperature quantum field theory, employing various parameters to represent different physical scenarios. Using these spectral functions, transport coefficients related to the spin alignment and tensor polarization are obtained, connecting the spin alignment of the $\varphi$ meson to hydrodynamic gradients. Using the standard freeze-out picture within the relativistic hydrodynamic model, we explore how the possible pattern of the spin alignment can be generated using these microscopically calculated spectral functions. We discover that, with certain assumptions, these simple microscopic model-based calculations can produce sizable spin alignments with a sign-flipping behavior in their $p_T$ and centrality dependence, similar to those observed in experiments.

    ↳ nucl-thhep-phhep-thnucl-ex2 citations
36. 36*

    Constraints on violation of Lorentz symmetry with clock-comparison redshift experiments

    Cheng-Gang Qin🇨🇳 · Yu-Jie Tan🇨🇳 · Xiao-Yu Lu🇨🇳 · Tong Liu🇨🇳 · Yan-Rui Yang🇨🇳 · Qin Li🇨🇳 · Cheng-Gang Shao🇨🇳

    Lorentz symmetry is a cornerstone of both the General relativity and Standard Model and its experimental verification deepens our understanding of nature. This paper focuses on the investigation of Lorentz violations with the context of clock comparison experiments in the framework of Standard Model Extension (SME). Considering matter-gravity coupling sector, we provide a generic frame to study the sensitivities of Lorentz-violating coefficients for three distinct types of clock redshift tests, including the traditional gravitational redshift test, null-redshift test I and null-redshift test II. Each of these tests is sensitivity to different combinations of Lorentz-violating coefficients. By using the current clock comparison results, we estimate the limits of SME coefficients at level of parts in $10^4$ down to parts in $10^7$. Better sensitivity may be achieved in the clock comparisons by using the state-of-the-art optical clocks. Additionally considering relativistic factors in null-redshift I, the frequency comparison result of E2 and E3 transitions of Yb${}^{+}$ can set the limit $c_{00}^e=(7.4\pm 9.3)\times 10^{-9}$ in the electron sector. Our analysis demonstrates that clock-comparison redshift experiments may contribute to explore the vast parameters space on searching for the Lorentz violation.

    ↳ gr-qcastro-ph.COhep-phphysics.atom-phPRD(2025)·7 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.