Tue·Aug 20, 2024Tuesday·August 20, 2024

1. 01*

   Double pole structures of $X_1(2900)$ as the $P$-wave ${\bar{D}}^{\ast }{K}^{\ast }$ resonances

   Jun-Zhang Wang🇨🇳 · Zi-Yang Lin🇨🇳 · Bo Wang🇨🇳 · Lu Meng🇩🇪 · Shi-Lin Zhu🇨🇳

   We reveal the double pole structures of the manifestly exotic tetraquark state $X_1(2900)$ in the scenario of $P$-wave ${\bar{D}}^{\ast }{K}^{\ast }$ dimeson resonance. We find that the observed enhancement signal associated with $X_1(2900)$ in $B^{+}\to D^{+}{D}^{-}{K}^{+}$ by LHCb contains two $P$-wave poles denoted as $T_{cs1-}(2900)$ and $T_{cs1-}^{\prime }(2900)$, respectively. After considering the channel couplings among the $\bar{D}K$, ${\bar{D}}^{\ast }K$, $\bar{D}{K}^{\ast }$ and ${\bar{D}}^{\ast }{K}^{\ast }$ and the width of the $K^{\ast }$ meson, the masses and widths of the $S$-wave pole $T_{cs0+}(2900)$ and two $P$-wave poles $T_{cs1-}(2900)$ and $T_{cs1-}^{\prime }(2900)$ coincide with those of the $X_0(2900)$ and $X_1(2900)$ remarkably, which provides strong support for identifying $X_0(2900)$ and $X_1(2900)$ as ${\bar{D}}^{(\ast )}{K}^{(\ast )}$ dimeson states. Furthermore, we extensively calculate all $S$-wave and $P$-wave ${\bar{D}}^{(\ast )}{K}^{(\ast )}$ systems up to $J=3$ and predict four new isoscalar charmed-strange dimeson-type tetraquark states: an $S$-wave state $T_{cs1+}(2900)$ with quantum number $J^P=1^{+}$, three $P$-wave states $T_{cs1-}(2760)$ with $J^P=1^{-}$, $T_{cs0-}(2760)$ with $J^P=0^{-}$ and $T_{cs2-}(2900)$ with $J^P=2^{-}$. These near-threshold poles can be searched for at LHCb, Belle II and BESIII.

   hep-phhep-exhep-latPRD(2024)·15 citations
2. 02*

   Polarization effects in the elastic $e\vec{p}\to \vec{e}p$ and $\vec{e}\vec{p}\to ep$ processes in the case of parallel spins

   M.V. Galynskii🇧🇾 · V.V. Bytev🇷🇺 · V.M. Galynsky

   In the one-photon exchange approximation, we analyze polarization effects in the elastic $\vec{e}\vec{p}\to ep$ and $e\vec{p}\to \vec{e}p$ processes in the case when the spin quantization axes of a target proton at rest and an incident or scattered electron are parallel. To do this, in the kinematics of the SANE Collaboration experiment, using the J. Kelly and I. Qattan parametrizations for the Sachs form factor ratio $R\equiv {\mu }_p{G}_E/G_M$, a numerical analysis was carried out of the dependence of the longitudinal polarization degree transferred to the scattered electron in the $e\vec{p}\to \vec{e}p$ process and double spin asymmetry in the $\vec{e}\vec{p}\to ep$ process on the square of the momentum transferred to the proton as well as on the scattering angle of the electron. It is established that the difference in the longitudinal polarization degree of the scattered electron in the $e\vec{p}\to \vec{e}p$ process in the case of conservation and violation of the scaling of the Sachs form factors can reach 70 \%. This fact can be used to set up polarization experiments of a new type to measure the ratio $R$. For double spin asymmetry in the $\vec{e}\vec{p}\to ep$ process, the corresponding difference does not exceed 2.32 \%. This fact means that it's not sensitive to the effects of the Sachs form factor scaling violation and could be used as test for the $R\approx 1$ equality.

   hep-phPRD(2024)·4 citations
3. 03*

   Status and Developments in Polarised Parton Distribution Functions

   Amedeo Chiefa🇬🇧

   The need for accurate and precise polarised parton distribution functions (PDFs) is becoming increasingly crucial in view of the Electron-Ion Collider experimental program foreseen in the coming years. Two global PDF determinations at next-to-next-to-leading order accuracy have been recently presented, MAPPDFpol1.0 and BDSSV24. I review the former and I provide a comparative discussion of other PDF sets accurate to next-to-leading order. I show that differences between these PDF sets, due to the choice of experimental and methodological input, exceed differences due to perturbative accuracy.

   hep-phPoS(2025)·0 citations
4. 04*

   Effective range expansion with a long-range force

   Meng-Lin Du🇨🇳 · Feng-Kun Guo🇨🇳 · Bing Wu🇨🇳

   The validity range of the time-honored effective range expansion can be very limited due to the presence of a left-hand cut close to the two-particle threshold. Such a left-hand cut arises in the two-particle interaction involving a light particle exchange with a mass small or slightly heavier than the mass difference of the two particles, identified as a long-range force, a scenario encountered in a broad range of systems. This can hinder a precise extraction of low-energy scattering observables and resonance poles. To address this issue, we propose a new parameterization for the low-energy scattering amplitude that accounts for the left-hand cut. The parameterization is like a Padé approximation but with nonanalytic terms from the left-hand cut and can be regarded as an extension of the effective range expansion. This parameterization is versatile and applicable to a broad range of systems with Yukawa-type interactions -- including particle, hadronic, nuclear, cold atom and quantum gas systems. In particular, it should be invaluable in understanding various near-threshold hadron resonances. As byproducts, we also show that the parameterization can be used to extract the couplings of the exchanged particle to the scattering particles, and derive expressions for amplitude zeros caused by the interplay between the short- and long-range interactions.

   hep-phcond-mat.quant-gashep-latnucl-thPRL(2025)·13 citations
5. 05*

   Transition signatures for electron-positron pair creation in space-time inhomogeneous electric field

   C. K. Li🇨🇳 · X. X. Zhou🇨🇳 · Q. Chen🇨🇳 · B. An🇨🇳 · Y. J. Li🇨🇳 · N. S. Lin🇨🇳 · Y. Wan🇨🇳

   The process of electron-positron pair creation through multi-photon absorption in a space-time dependent electric field is analyzed using computational quantum field theory. Our findings reveal two distinct pair creation channels: the symmetric and asymmetric transition channels. We propose that the asymmetric transition channel arises from the inherent spatial inhomogeneity of intense laser pulses. By mapping the field-theoretical model of laser-assisted multi-photon pair creation onto a quantum-mechanical time-dependent framework, a semi-analytical solution that captures the asymmetric transition signatures of vacuum decay is derived. Additionally, it is demonstrated that neglecting spatial inhomogeneity leads to erroneous transition amplitudes and incorrect identification of pair creation channels. Furthermore, we have established that asymmetric transition channels substantially enhance the creation of electron-positron pairs for a given laser pulse energy.

   hep-phphysics.plasm-phChin.Phys.B(2026)·3 citations
6. 06*

   Forward ${\eta }_Q$ production impact factor at NLO

   Maxim Nefedov🇫🇷

   The High-Energy Factorisation (HEF) coefficient function or impact factor for the hadroproduction of the state ${}^1{S}_0^{[1]}$ of a heavy quark-antiquark pair ($Q\bar{Q}$) at forward rapidities is computed at NLO in ${\alpha }_s$. This impact factor is an integral part of the resummation procedure for higher-order QCD corrections to the hadroproduction cross sections of ${\eta }_c$ or ${\eta }_b$ mesons at forward rapidities in collinear factorisation (CF), enhanced by logarithms of partonic center of mass energy. The NLO computation results of which are presented in this contribution, is an important step towards an extension of aforementioned resummation beyond the Leading Logarithmic Approximation(LLA).

   hep-phhep-exPoS(2025)·2 citations
7. 07*

   Chiral Symmetry and Large Magnetic Fields

   Prabal Adhikari🇺🇸 · Brian C. Tiburzi🇺🇸

   Large magnetic fields exist in magnetars and are produced in off-central heavy-ion collisions. For the latter, field strengths are estimated to be comparable to strong interaction scales. This fact has motivated many studies of QCD physics in large magnetic fields, ranging from various model studies to lattice QCD computations. We provide a selective overview of results stemming from chiral perturbation theory. These results are based solely on the pattern of spontaneous and explicit symmetry breaking of QCD in a magnetic field; accordingly, they constitute low-energy theorems that must be satisfied in any approach. A few discrepancies with models and tension with lattice data are highlighted.

   hep-phhep-latPoS(2025)·1 citation
8. 08*

   Dissecting a strongly coupled scalar nucleon

   Xianghui Cao🇨🇳 · Yang Li🇨🇳 · James P. Vary🇺🇸

   We continue our investigation of the stress within a strongly coupled scalar nucleon, and now dissect the gravitational form factors into contributions from its constituents, the (mock) nucleon and the (mock) pion. The computation is based on a non-perturbative solution of the scalar Yukawa model in the light-front Hamiltonian formalism with a Fock sector expansion including up to one nucleon and two pions. By employing the ``good currents" $T_i^{++}$, $T_i^{+-}$ and $T_i^{12}$, we extract the full set of gravitational form factors $A_i$, $D_i$, ${\bar{c}}_i$ without the contamination of the spurious form factors, and free of uncanceled UV divergences. With these results, we decompose the mass of the system into its constituents and compute the matter and mechanical radii, gaining insights into the strongly coupled system.

   hep-phhep-thnucl-thPRD(2024)·6 citations
9. 09*

   Sensitivity of WIMP bounds on the velocity distribution in the limit of a massless mediator

   Koun Choi (IBS, Daejeon)🇰🇷 · Injun Jeong (CQUeST and Sogang U.)🇰🇷 · Sunghyun Kang (CQUeST and Sogang U.)🇰🇷 · Arpan Kar (CQUeST and Sogang U.)🇰🇷 · Stefano Scopel (CQUeST and Sogang U.)🇰🇷

   We discuss the sensitivity of the bounds on the spin-independent (SI) and spin-dependent (SD) WIMP-proton and WIMP-neutron interaction couplings ${\alpha }_{SI,SD}^{p,n}$ on the WIMP velocity distribution for a massless mediator in the propagator by combining direct detection and the neutrino signal from WIMP annihilation in the Sun (fixing the annihilation channel to $b\bar{b}$). We update the bounds in the Standard Halo Model (SHM) and using the halo-independent single-stream method. In the case of a massless mediator the SHM capture rate in the Sun diverges and is regularized by removing the contribution of WIMPs locked into orbits that extend beyond the Sun-Jupiter distance. We discuss the dependence of the SHM bounds on the Jupiter cut showing that it can be sizeable for ${\alpha }_{\mathrm{SD}}^p$ and a WIMP mass $m_{\chi }$ exceeding 1 TeV. Our updated SHM bounds show an improvement between about two and three orders of magnitude compared to the previous ones in the literature. Our halo-independent analysis shows that, with the exception of ${\alpha }_{\mathrm{SD}}^p$ at large $m_{\chi }$, the relaxation of the bounds compared to the SHM is of the same order of that for contact interactions, i.e. relatively moderate in the low and high WIMP mass regimes and as large as a few $\times \sim 10^2$ for $m_{\chi }\simeq$ 20 GeV. On the other hand, the exact determination of the relaxation of the bound becomes not reliable for ${\alpha }_{\mathrm{SD}}^p$ and $m_{\chi }\gtrsim$ 1 TeV due to the sensitivity of the SHM capture rate in the Sun to the details of the Maxwellian velocity distribution at low incoming WIMP speeds. The halo-independent bounds do not depend on the Jupiter cut needed to regularize the calculation of the capture rate.

   hep-phastro-ph.COJCAP(2025)·5 citations
10. 10*

    First-order Electroweak phase transition with Gauge-invariant approach

    Renhui Qin🇨🇳 · Ligong Bian🇨🇳

    We study the electroweak phase transition dynamics with a three-dimensional standard model effective field theory under a gauge-invariant approach. We observe that, at the two-loop level, the phase transition parameters obtained with the gauge invariant approach can at most deviate from that of the dimensional reduction method around the percent level. We further found that the predicted gravitational wave signals at the new physics scale $\Lambda \gtrsim 590$ GeV are unreachable by the space-based interferometers, such as: LISA, TianQin, and Taiji.

    hep-phastro-ph.COhep-thPRD(2025)·16 citations
11. 11*

    Gravitational form factor $D$ of charmonium from shear stress

    Tianyang Hu🇨🇳 · Xianghui Cao🇨🇳 · Siqi Xu🇨🇳 · Yang Li🇨🇳 · Xingbo Zhao🇨🇳 · James P. Vary🇺🇸

    Based on our recent analysis of the hadronic matrix element of the stress-energy tensor in covariant light front dynamics, we extract the charmonium gravitational form factor $D(Q^2)$ from shear stress $T^{12}$. This is in contrast to our recent work using the (light-front) energy density $T^{+-}$. Indeed, by comparing these two currents, we identify terms that are responsible for the violation of the current conservation. Numerical results based on basis light-front quantization show that the violation effects are small and the $D$-term extracted from the two currents are close to each other, hence validating our previous work using $T^{+-}$.

    hep-phnucl-thPRD(2025)·12 citations
12. 12*

    Gluon tomography through diffractive processes in a saturation framework

    Renaud Boussarie🇫🇷 · Michael Fucilla🇫🇷 · Andrey V. Grabovsky🇷🇺 · Emilie Li🇫🇷 · Lech Szymanowski🇵🇱 · Samuel Wallon🇫🇷

    We discuss a series of results aimed at bringing saturation physics and gluon tomography into an era of precision. In particular, the NLO treatment of diffractive: 1) exclusive dijet, 2) exclusive longitudinally polarized light vector meson and 3) semi-inclusive single or double hadron photo- or electroproduction with large $p_T$, on a nucleon or a nuclei. Finally, we discuss the more complicated 4) exclusive transversely polarized light vector meson production, which starts at the next-to-leading power and therefore requires a beyond leading twist treatment. This new class of processes provides an access to precision physics of gluon saturation dynamics, with very promising future phenomenological studies at the EIC, or, at the LHC in $pA$ and $AA$ scattering, using Ultra Peripheral Collisions (UPC).

    hep-phhep-thPoS(2025)·2 citations
13. 13*

    Transport coefficients of the heavy quark in the domain of the non-perturbative and non-eikonal gluon radiation

    Surasree Mazumder🇮🇳 · Natasha Sharma🇮🇳 · Lokesh Kumar🇮🇳

    Drag and diffusion coefficients of the Heavy Quarks (HQs), such as charm and bottom, are one of the prime tools for discerning the properties of the deconfined QCD medium created in the Heavy Ion Collisions experiments. The innate non-perturbative nature of the QCD medium renders it imperative to estimate the transport coefficients in that domain. The present work evaluates the drag and diffusion coefficients of the moving HQ interacting with the medium particles via two-body collisional and three-body radiative processes to the first order in opacity by employing Gribov mechanism for the non-perturbative regime. We proffer the latest results of the HQ transport coefficients computed for the non-perturbative and non-eikonal gluon radiation off the HQ. The calculations show significant increment of the transport coefficients with the increasing non-eikonality by juxtaposing the results with those of the pertubative and eikonal regions. We hope to shed fresh light towards explaining the experimental data on the nuclear modification facor, $R_{AA}$, the elliptic flow, $v_2$ of the HQ by advocating the importance of the non-eikonality of the gluon radiation off the HQ.

    hep-phnucl-thPRC(2025)·2 citations
14. 14*

    Collisional corrections to spin polarization from quantum kinetic theory using Chapman-Enskog expansion

    Shuo Fang🇨🇳 · Shi Pu🇨🇳

    We have investigated the collisional corrections to the spin polarization pseudo-vector, $\delta {\mathcal{P}}^{\mu }$, using quantum kinetic theory in Chapman-Enskog expansion. We derive the spin Boltzmann equation incorporating Møller scattering process. We further consider two distinct scenarios using hard thermal loop approximations for simplification. In scenario (I), the vector charge distribution function is treated as off-equilibrium under the validity domain of gradient expansion. Remarkably, the polarization induced by gradients of thermal chemical potential and shear viscous tensors are modified, but $\delta {\mathcal{P}}_{}^{\mu }$ in this scenario does not depend on the coupling constant. In scenario (II), the vector charge distribution function is assumed to be in local thermal equilibrium. Then collisional corrections $\delta {\mathcal{P}}_{}^{\mu }$ in this scenario are at $\mathcal{O}({\hslash }^2{\partial }^2)$. Additionally, we evaluate the $\delta {\mathcal{P}}^{\mu }$ using relaxation time approach for comparative analysis. Our results establish the theoretical framework necessary for the future numerical investigations on the interaction corrections to spin polarization.

    hep-phhep-thnucl-thPRD(2025)·25 citations
15. 15*

    Quark Flavor Balancing in Nuclear Collisions

    Yash Patley🇮🇳 · Basanta Nandi🇮🇳 · Sadhana Dash🇮🇳 · Victor Gonzalez🇺🇸 · Claude Pruneau🇺🇸

    The notion of charge balance function, originally designed to study the evolution of charge production in heavy-ion collisions, is extended to consider quark flavor balancing. This extension is considered based on simulations performed with the PYTHIA 8 event generator in the context of pp collisions at $\sqrt{s}=13.6$ TeV but can be trivially applied to any other scenario and implemented in measurements of correlated particle production in pp, pA, and AA collisions at colliders. Correlation of selected flavor balancing pairs are examined as function of the produced charged particle multiplicity. One finds that the amplitude of the correlations increases monotonically with the number of balanced flavors and the actual flavor content of correlated particles.

    hep-phPRC(2025)·1 citation
16. 16*

    Electron-nucleus cross sections from transfer learning

    Krzysztof M. Graczyk🇵🇱 · Beata E. Kowal🇵🇱 · Artur M. Ankowski🇵🇱 · Rwik Dharmapal Banerjee🇵🇱 · Jose Luis Bonilla🇵🇱 · Hemant Prasad🇵🇱 · Jan T. Sobczyk🇵🇱

    Transfer learning (TL) allows a deep neural network (DNN) trained on one type of data to be adapted for new problems with limited information. We propose to use the TL technique in physics. The DNN learns the details of one process, and after fine-tuning, it makes predictions for related processes. We consider the DNNs, trained on inclusive electron-carbon scattering data, and show that after fine-tuning, they accurately predict cross sections for electron interactions with nuclear targets ranging from helium-3 to iron.

    hep-phcs.LGhep-exnucl-ex+1PRL(2025)·7 citations
17. 17*

    Chiral-odd gluon generalized parton distributions in the proton: A light-front quantization approach

    Bolang Lin🇨🇳 · Sreeraj Nair🇨🇳 · Chandan Mondal🇨🇳 · Siqi Xu🇨🇳 · Zhi Hu🇯🇵 · Pengxiang Zhang🇨🇳 · Xingbo Zhao🇨🇳 · James P. Vary🇺🇸

    Within the basis light-front quantization (BLFQ) framework, we evaluate the gluon chiral-odd generalized parton distributions (GPDs) inside the proton at zero skewness. We employ the light-front wave functions of the proton obtained from a light-front quantized Hamiltonian with quantum chromodynamics input using BLFQ. Our investigation encompasses both the valence Fock sector with three constituent quarks and an additional sector containing three quarks and a dynamical gluon. We analyze the gluon GPDs in the momentum space as well as in the transverse position space. We further present the gluon's generalized form factors derived from the Mellin moments of its chiral-odd GPDs. Using the proton transverse spin sum rule, we also present the $x$-dependence of the angular momentum carried by the polarized gluon and determine the relative contributions of quarks and the gluon to the transversity asymmetry.

    hep-phPLB(2025)·13 citations
18. 18*

    MSHT Updates 2024

    R.S. Thorne🇬🇧 · T. Cridge🇩🇪 · L. Harland-Lang🇬🇧

    We present various recent updates related to the MSHT20 PDF sets, and particularly to the MSHT20 approximate N${}^3$LO (aN${}^3$LO) PDFs. These include an investigation of including either inclusive jet data or dijet data, the detailed treatment of $Z{p}_T$ data, and the impact on the gluon PDF in particular. We also very briefly summarize the determination of the strong coupling via an aN${}^3$LO global PDF fit, finding ${\alpha }_S(M_Z^2)=0.1170\pm 0.0016$, and of including QED corrections in the aN${}^3$LO analysis. Finally we consider the preliminary finding associated with the effect of improved knowledge of the N${}^3$LO splitting functions on the aN${}^3$LO PDFs. In particular we note a moderate impact on the gluon distribution, i.e. within the uncertainty, and a more limited impact on the gluon-gluon luminosity unless strong rapidity cuts are imposed. Hence, we conclude that while details of our aN${}^3$LO PDFs will change with more precise splitting functions, only relatively minor effects on predictions are likely to result.

    hep-phhep-ex2 citations
19. 19*

    The contribution of new physics on the exclusive W boson hadronic decays in the final state at muon colliders in the Randall-Sundrum model

    Bui Thi Ha Giang🇻🇳 · Dang Van Soa🇻🇳

    An attempt is made to present the effect of new physics in the exclusive decays of W boson at high energy colliders in the Randall-Sundrum (RS) model. By using Feynman diagram techniques we have evaluated the influence of the scalar unparticle, polarization and anomalous couplings on the exclusive W boson hadronic decays of $W^{\pm }\to {\pi }^{\pm }\gamma$, $W^{\pm }\to K^{\pm }\gamma$ and $W^{\pm }\to {\rho }^{\pm }\gamma$ at the high energy muon colliders in the RS model. The result shows that with fixed collision energies, the total cross-section for hadronic productions in the final state depends strongly on the parameters of the unparticle physics, muon beam polarizes and also anomalous couplings. With a center-of-mass energy of 10 TeV, the total cross-sections achieve the maximum value when the benchmark signal point as $({\Lambda }_U,d_U)$ $=(1\text{TeV},1.9)$ and the polarization coefficient as $(P_{{\mu }^{-}},P_{{\mu }^{+}})=(1,1)$. The numerical evaluation shows that with the contribution of new physics in the RS model, the effect is greatly enhanced at high energy colliders. The statistical significance can reach $1\sigma -7\sigma$ in case of using the W branching ratio at the experimental bounds of $\mathcal{O}(10^{-6})$. To clarify the contribution of new physics, we use a ${\chi }^2$ analysis with systematic errors to determine the sensitivities of the new contributions. The result indicates that the sensitivities on the anomalous coupling $WW\gamma$ are much larger than that on the anomalous coupling $WWZ$ under the same conditions.

    hep-ph1 citation
20. 20*

    Dark Sector Showers and Hadronisation in Herwig 7

    Suchita Kulkarni🇦🇹 · M.R. Masouminia🇬🇧 · Simon Plätzer🇦🇹 · Dominic Stafford🇩🇪

    We present a novel simulation of a strongly interacting dark sector also known as the Hidden Valley scenarios using angular ordered showers and the cluster hadronisation model in Herwig 7. We discuss the basics of this implementation and the scale hierarchies underpinning the simulation. With the help of a few benchmarks, we show the effect of variation of dark sector parameters on thrust and angularities within the dark sector, and study correlation functions, which can be helpful for understanding the angular structure of these events. Finally we comment on the uncertainties introduced due to lack of knowledge of hadronisation parameters within the dark sectors.

    hep-phhep-exEPJC(2024)·12 citations
21. 21*

    Could Ball Lightning Be Magnetic Monopoles?

    Karl D. Stephan (Texas State University)🇺🇸

    While magnetic monopoles have extensive theoretical justification for their existence, but have proved elusive to observe, ball lightning is both relatively frequently observed and largely unexplained theoretically. It was first proposed in 1990 that ball lightning might result from the catalysis of nuclear fission by a magnetic monopole. The observed frequency of ball lightning does not conflict with current upper theoretical or observational bounds for magnetic monopole flux. Some possible mechanisms to account for the association of magnetic-monopole-caused ball lightning with thunderstorms are described, and proposals for further observational and theoretical research are made.

    hep-phphysics.geo-ph3 citations
22. 22*

    High-Quality Axions from Higher-Form Symmetries in Extra Dimensions

    Nathaniel Craig🇺🇸 · Marius Kongsore🇺🇸

    The extra-dimensional axion solves the strong CP problem while largely circumventing the quality problem that plagues its four-dimensional counterparts. Such high quality can be clearly understood in terms of the generalized global symmetries of the higher-dimensional theory. We emphasize that an electric one-form symmetry is entirely responsible for protecting the potential of axions arising from 5D gauge theories and use this to systematically characterize the extra-dimensional axion quality problem. We identify three ways of breaking this one-form symmetry to generate an axion potential: adding electrically charged matter, gauging a magnetic higher-form symmetry, and turning on an ABJ anomaly. In the latter case, we identify new ways of generating an axion potential via extra-dimensional magnetic monopoles. We also discuss how the axion is modified if the protective electric one-form symmetry is itself gauged. Finally, we relate these effects to gravitational expectations for the quality problem via generalized weak gravity conjectures. The clarity that generalized symmetries bring to the extra-dimensional axion quality problem highlights their relevance to particle phenomenology.

    hep-phhep-thPRD(2025)·39 citations
23. 23*

    Star Shearing Season -- Transient Signals in Wave-like Dark Matter Experiments from Black Hole Formation

    Arturo de Giorgi🇪🇸 · Joerg Jaeckel🇩🇪

    Ordinary matter coupled to light weakly interacting bosons can lead to the formation of a macroscopic bosonic field in the vicinity of large matter concentrations such as ordinary or neutron stars. When these objects are turned into black holes due to a supernova or a binary merger this ''hair'' could be ''shorn'' off. Part of the field configuration would then be released leading to an outgoing field wave. For small masses this field transient remains rather compact and can induce a transient signal in experiments, in particular those that look for wave-like dark matter. This signal can be correlated with the corresponding astrophysical signal of the event. In this note, we consider a variety of couplings and the associated signals and estimate the corresponding sensitivities.

    hep-phhep-exEPJC(2025)·6 citations
24. 24*

    Spontaneous symmetry breaking, gauge hierarchy and electroweak vacuum metastability

    Sean Benevedes🇺🇸 · Thomas Steingasser🇺🇸 · Sokratis Trifinopoulos🇺🇸

    The so-called metastability bound asserts that an unnaturally small Higgs mass is a necessary condition for electroweak vacuum metastability, offering a new approach towards solving the hierarchy problem. So far, this result relies on the assumption of a negative Higgs mass parameter, or equivalently, on electroweak spontaneous symmetry breaking. We derive a new, corresponding bound for the case of a positive mass parameter. When the new bound is significantly more restrictive than or comparable to its established counterpart, it may offer an explanation for the sign of the Higgs mass parameter, and thus, spontaneous symmetry breaking itself. New physics at scales $\mathcal{O}(1-10)$ TeV can lower these bounds as far as the TeV-scale. As an illustration, we consider vacuum stability in the presence of additional TeV-scale fermions with Yukawa couplings to the Higgs, as well as a dimension-six term parameterizing new physics in the UV. This scenario requires new physics that couples strongly to the Higgs, and can potentially be probed at future colliders. Finally, to allow for comparison with concrete mechanisms predicting metastability, we provide the mass-dependent lifetime of the electroweak vacuum for this model.

    hep-phastro-ph.COhep-thPRD(2024)·8 citations
25. 25*

    Factorization restoration through Glauber gluons

    Thomas Becher🇨🇭 · Patrick Hager🇩🇪 · Sebastian Jaskiewicz🇨🇭 · Matthias Neubert🇺🇸 · Dominik Schwienbacher🇨🇭

    We analyze the low-energy dynamics of gap-between-jets cross sections at hadron colliders, for which phase factors in the hard amplitudes spoil collinear cancellations and lead to double (``super-leading'') logarithmic behavior. Based on a method-of-regions analysis, we identify three-loop contributions from perturbative active-active Glauber-gluon exchanges with the right structure to render the cross section consistent with PDF factorization below the gap veto scale. The Glauber contributions we identify are unambiguously defined without regulators beyond dimensional regularization.

    hep-phhep-thPRL(2025)·31 citations
26. 26*

    Toward a first-principles description of transverse momentum dependent Drell-Yan production in proton-nucleus collisions

    Weiyao Ke🇨🇳 · John Terry🇺🇸 · Ivan Vitev🇺🇸

    In this paper, we study the parton dynamics in Drell-Yan collisions involving proton-nuclei interactions in the limit of small transverse momentum, emphasizing the role of the cold nuclear matter effects. The distribution of transverse momentum that enter into these collisions differs from that in Drell-Yan collisions with free nucleons in two distinct ways: the intrinsic parton structure of the TMDs are altered, the perturbative dynamics undergo additional modification due to interactions with the nuclear medium. In this paper, we focus on the perturbative dynamics, which we demonstrate enter from forward scattering between the parton constituents of the proton and the nuclear medium. We then derive these partonic contributions to the TMD Drell-Yan cross section up to next-to-leading order in the strong coupling constant and to the first order in the medium opacity. We demonstrate that the collinear and rapidity divergences related to parton showers in matter lead to i) an in-medium renormalization group equation that encodes the transverse momentum dependence of parton energy loss, and ii) a Balitsky-Fadin-Kuraev-Lipatov evolution equation for the forward scattering cross section. We discuss the relation of our results to the phenomenological extraction of nuclear TMDs and apply the new formalism to Drell-Yan production at small transverse momenta in $p$+$A$ reactions.

    hep-phJHEP(2025)·6 citations
27. 27*

    Positivity Bounds in Scalar Effective Field Theories at One-loop Level

    Yunxiao Ye🇨🇳 · Bin He🇨🇳 · Jiayin Gu🇨🇳

    Parameters in an effective field theory can be subject to certain positivity bounds if one requires a UV completion that obeys the fundamental principles of quantum field theory. These bounds are relatively straightforward at the tree level, but would become more obscure when loop effects are important. Using scalar theories as examples, we carefully exam the positivity bounds in a case where the leading contribution to a forward elastic amplitude arises at the one-loop level, and point out certain subtleties in terms of the implications of positivity bounds on the theory parameter space. In particular, the one-loop generated dimension-8 operator coefficients (that would be positive if generated at the tree level), as well as their $\beta$-functions are generally not subject to positivity bounds as they might correspond to interference terms of the cross sections under the optical theorem, which could have either sign. A strict positivity bound can only be implied when all contributions at the same loop order are considered, including the ones from dim-4 and dim-6 operator coefficients, which have important effects at the one-loop level. Our results may have important implications on the robustness of experimental tests of positivity bounds.

    hep-phhep-thJHEP(2024)·16 citations
28. 28*

    Theory-agnostic searches for non-gravitational modes in black hole ringdown

    Francesco Crescimbeni🇮🇹 · Xisco Jimenez Forteza🇪🇸 · Swetha Bhagwat🇬🇧 · Julian Westerweck🇬🇧 · Paolo Pani🇮🇹

    In any extension of General Relativity (GR), extra fundamental degrees of freedom couple to gravity. Besides deforming GR forecasts in a theory-dependent way, this coupling generically introduces extra modes in the gravitational-wave signal. We propose a novel theory-agnostic test of gravity to search for these nongravitational modes in black hole merger ringdown signals. To leading order in the GR deviations, their frequencies and damping times match those of a test scalar or vector field in a Kerr background, with only amplitudes and phases as free parameters. By applying this test to GW150914, GW190521, and GW200129, we find no strong evidence for an extra mode; however, its inclusion modifies the inferred distribution of the remnant spin. This test will be applicable for future detectors, which will achieve signal-to-noise ratios higher than 100 (and as high as 1000 for space-based detectors such as LISA). Such sensitivity will allow measurement of these modes with amplitude ratios as low as 0.02 for ground-based detectors (and as low as 0.003 for LISA), relative to the fundamental mode, enabling stringent agnostic constraints or detection of scalar/vector modes.

    ↳ gr-qcastro-ph.HEhep-phSciPost Phys.(2026)·20 citations
29. 29*

    Dynamical Dark Energy from Lattice Quantum Gravity

    Mingwei Dai🇺🇸 · Walter Freeman🇺🇸 · Jack Laiho🇺🇸 · Marc Schiffer🇨🇦 · Judah Unmuth-Yockey🇺🇸

    We study the behavior of the vacuum in Euclidean dynamical triangulations (EDT). Algorithmic improvements and better lattice spacing determinations allow us to test the properties of the emergent de Sitter geometries of our simulations to higher precision than previously possible. Although the agreement with de Sitter is good, the improved precision reveals deviations that can be interpreted as non-trivial vacuum dynamics, well-described by a cosmological constant that runs with scale. The simulations show that the dominant running is quadratic and that the scale can be identified with the Hubble rate. Several key cross-checks support this picture, including consistent results across multiple lattice spacings and the fact that the null energy condition is not violated. The parameters of the running are fully determined by simulations, enabling predictions when extrapolated to the scales relevant for our universe. This leads to a model for dark energy that is compatible with current observations, but which predicts deviations from $\Lambda$CDM at the $\mathcal{O}(10^{-3})$ level in cosmological observables that could be tested with future improvements in precision measurements.

    ↳ hep-latgr-qchep-phhep-thPRD(2025)·13 citations
30. 30*

    Investigating the mixing between two black hole populations in LIGO-Virgo-KAGRA GWTC-3

    Ming-Feng Ho🇺🇸 · Scott Ellis Perkins🇺🇸 · Simeon Bird🇺🇸 · William Dawson🇺🇸 · Nathan Golovich🇺🇸 · Jessica R. Lu🇺🇸 · Peter McGill🇺🇸

    We introduce a population model to analyze the mixing between hypothesised power-law and $\sim 35M_{\odot }$ Gaussian bump black hole populations in the latest gravitational wave catalog, GWTC-3, estimating their co-location and separation. We find a relatively low level of mixing, $3.1_{-3.1}^{+5.0}\%$, between the power-law and Gaussian populations, compared to the percentage of mergers containing two Gaussian bump black holes, $5.0_{-1.7}^{+3.2}\%$. Our analysis indicates that black holes within the Gaussian bump are generally separate from the power-law population, with only a minor fraction engaging in mixing and contributing to the $\mathcal{M}\sim 14M_{\odot }$ peak in the chirp mass. This leads us to identify a distinct population of Binary Gaussian Black Holes (BGBHs) that arise from mergers within the Gaussian bump. We suggest that current theories for the formation of the massive $35M_{\odot }$ Gaussian bump population may need to reevaluate the underlying mechanisms that drive the preference for BGBHs.

    ↳ astro-ph.HEastro-ph.COastro-ph.GAastro-ph.SR+1PRD(2024)·2 citations
31. 31*

    Modeling net-charge fluctuations in heavy-ion collisions at the LHC

    G.O. Ambaryan🇷🇺 · A.S. Chernyshov🇷🇺 · G.Kh. Eyyubova🇷🇺 · V.L. Korotkikh🇷🇺 · I.P. Lokhtin🇷🇺 · S.V. Petrushanko🇷🇺 · A.M. Snigirev🇷🇺 · E.E. Zabrodin🇷🇺

    The analysis of Pb+Pb data for net-charge fluctuations at LHC energies within the HYDJET++ model is presented. The strongly intensive quantities $D$ and $\Sigma$ are used to get rid of the effects related to volume fluctuations of the system. We employ two versions of the HYDJET++ for the analysis. The first one is the standard or default version, whereas the second one represents its further modification, which takes into account explicit event-by-event conservation of the electric net-charge of produced particles. Inclusion of the canonical net-charge conservation in the model allows one for better description of the experimental data obtained by the ALICE and the CMS Collaborations. Comparison with calculations of other models is also presented.

    ↳ nucl-thhep-phnucl-exCPC(2025)·6 citations
32. 32*

    The Search for the Cosmological Axion -- A New Refined Narrow Mass Window and Detection Scheme

    Masroor H. S. Bukhari🇸🇦

    Based upon a previous axion mass proposal and detection scheme, as well as considering the axion mass ranges suggested by persuasive simulations in recent years, we present a revised axion/ALP search strategy and our calculations, concentrating on a slightly narrower axion mass (and corresponding Compton frequency) window in this report. The sole aim of this study was to provide a pin-point mass value for a resonant cavity detection scheme, and the outcome of calculations presented here reinforces the earlier mass window and the results (slightly different values from our calculations but within the same window) obtained by the calculations and simulations by Kawasaki et al. (2015) and Buschmann et al. (2020). The window comprises the spectral region of 18.99 to 19.01GHz (that falls within the Ku microwave band), with a center frequency of 19.00GHz (+0.1GHz), with equivalence to an axion mass range of 78.6 to 79.6 micro-eV, with the center mass at the value of 78.582 (+5.0) micro-eV, our suggested most likely value for an axionic/ALP field mass, if these fields exist. Our search strategy, as summarized herewith, is based upon the assumption that the dark matter that exists in the current epoch of our physical universe is dominated by axions and thus the local observable axion density is the density of the light cold dark matter, permeating our local neighborhood (mainly in the Milky Way galactic halo). Some ideas and the design of an experiment, based upon the inverse Primakoff effect, and built around a Josephson Parametric Amplifier and Resonant Tunneling Diode combination installed in a resonant RF cavity, are also some possibly novel ideas, as introduced in this report.

    ↳ hep-exhep-phOpen Phys.(2025)·1 citation
33. 33*

    AXPs/SGRs: strange stars with crusts?

    Guojun Qiao · Lunhua Shang · Renxin Xu🇨🇳 · Kejia Lee🇬🇷 · Yongquan Xue🇨🇳 · Qijun Zhi · Jiguang Lu · Juntao Bai🇨🇳

    The emission of Anomalous X-ray Pulsars (AXPs) and Soft Gamma-Ray Repeaters (SGRs) is believed to be powered by the dissipation of their strong magnetic fields, which coined the name `magnetar'. By combining timing and energy observational results, the magnetar model can be easily appreciated. From a timing perspective, the magnetic field strengths of AXPs and SGRs, calculated assuming dipole radiation, are extremely strong. From an energy perspective, the X-ray/soft gamma-ray luminosities of AXPs and SGRs are larger than their rotational energy loss rates (i.e., $L_{\mathrm{X}}>{\dot{E}}_{\mathrm{rot}}$). It is thus reasonable to assume that the high-energy radiation comes from magnetic energy decay, and the magnetar model has been extensively discussed (or accepted). However, we argue that: (1) calculating magnetic fields by assuming that rotational energy loss is dominated by dipole radiation (i.e., ${\dot{E}}_{\mathrm{rot}}\simeq {\dot{E}}_{\mu }$)) may be controversial, and we suggest that the energies carried by outflowing particles should also be considered; and (2) the fact that X-ray luminosity is greater than the rotational energy loss rate does not necessarily mean that the emission energy comes from the magnetic field decaying, which requires further observational testing. Furthermore, some observational facts conflict with the `magnetar' model, such as observations of anti-magnetars, high magnetic field pulsars, and radio and X-ray observations of AXPs/SGRs. Therefore, we propose a crusted strange star model as an alternative, which can explain many more observational facts of AXPs/SGRs.

    ↳ astro-ph.HEhep-ph0 citations
34. 34*

    Non-perturbative phase boundaries in the Gross-Neveu model from a stability analysis

    Michael Thies🇩🇪

    Two out of three phase boundaries of the 1+1 dimensional Gross-Neveu model in the chiral limit can be obtained from a standard, perturbative stability analysis of the homogeneous phases. The third one separating the massive homogeneous phase from the kink crystal is non-perturbative and could so far only be inferred from the full solution of the model. We show that this phase boundary can also be obtained via a modified stability analysis, based on the thermodynamic potential of a single kink or baryon. The same method works for the massive Gross-Neveu model, so that all phase boundaries of the Gross-Neveu model could have been predicted quantitatively without prior knowledge of the full crystal solution.

    ↳ hep-thhep-lathep-phPRD(2024)·5 citations
35. 35*

    Extended $\delta N$ formalism: Nonspatially Flat Separate Universe Approach

    Danilo Artigas🇯🇵 · Shi Pi🇨🇳 · Takahiro Tanaka🇯🇵

    The $\delta N$ formalism is a powerful approach to compute non-linearly the large-scale evolution of the comoving curvature perturbation $\zeta$. It assumes a set of FLRW patches that evolve independently, but in doing so, all the gradient terms are discarded, which are not negligibly small in models beyond slow-roll. In this Letter, we extend the formalism to capture these gradient corrections by encoding them in a homogeneous-spatial-curvature contribution assigned to each FLRW patch. For a concrete example, we apply this formalism to the ultra-slow-roll inflation, and find that it can correctly describe the large-scale evolution of the comoving curvature perturbation from the horizon exit. We also briefly discuss non-Gaussianities in this context.

    ↳ astro-ph.COgr-qchep-phhep-thPRL(2025)·31 citations
36. 36*

    Charming Darwin: the evolution of QCD parameters across different species

    Florian Bernlochner🇩🇪 · Alex Gilman🇬🇧 · Sneha Malde🇬🇧 · Markus Prim🇩🇪 · K. Keri Vos🇳🇱 · Guy Wilkinson🇬🇧

    We explore the prospects of measurements of spectral moments of inclusive charm decays with BESIII. The rich and uniquely clean data set of charm mesons and baryons at BESIII offers a unique laboratory to study the evolution of Heavy Quark Expansion (HQE) parameters across different charm hadron species and to shed light on the interplay between heavy quark dynamics and light quark effects. The HQE in terms of inverse powers of the heavy meson mass is well-established in beauty decays, however due to the lighter charm mass its applicability to charm remains an open question. To date no determination of the HQE parameters, the kinetic energy, chromomagnetic moment and Darwin terms, has been attempted. A particularly important role here is given to the Darwin and weak annihilation operators, whose values are important to predict lifetimes of heavy hadrons. Using a fast simulation for the BESIII detector response and predictions for spectral moments, we investigate the sensitivity to HQE parameters with today's and possible future data sets. In addition, we discuss the theory challenges for the HQE in charm and the experimental limitations. We further investigate the sensitivity of determining the CKM matrix element $|V_{cs}|$ with inclusive semileptonic charm decays.

    ↳ hep-exhep-phJHEP(2025)·5 citations
37. 37*

    Nuclear Fragmentation at the Future Electron-Ion Collider

    C. A. Bertulani🇺🇸 · Y. Kucuk🇹🇷 · F.S. Navarra🇧🇷

    We explore the potential of conducting low-energy nuclear physics studies, including nuclear structure and decay, at the future Electron-Ion Collider (EIC) at Brookhaven. By comparing the standard theory of electron-nucleus scattering with the equivalent photon method applied to Ultraperipheral Collisions (UPC) at the Large Hadron Collider (LHC) at CERN. In the limit of extremely high beam energies and small energy transfers, very transparent equations emerge. We apply these equations to analyze nuclear fragmentation in UPCs at the LHC and $eA$ scattering at the EIC, demonstrating that the EIC could facilitate unique photonuclear physics studies. However, we have also shown that the fragmentation cross-sections at the EIC are about 1,000 times smaller than those at the LHC. At the LHC, the fragmentation of uranium nuclei displays characteristic double-hump mass distributions from fission events, while at the EIC, fragmentation is dominated by neutron emission and fewer few fission products, about 10,000 smaller number of events.

    ↳ nucl-thhep-phnucl-exNPA(2025)·6 citations
38. 38*

    The NANOGrav 15 yr Data Set: Running of the Spectral Index

    Gabriella Agazie🇺🇸 · Akash Anumarlapudi🇺🇸 · Anne M. Archibald🇬🇧 · Zaven Arzoumanian🇺🇸 · Jeremy George Baier🇺🇸 · Paul T. Baker🇺🇸 · Bence Bécsy🇺🇸 · Laura Blecha🇺🇸 · Adam Brazier🇺🇸 · Paul R. Brook🇬🇧 · Sarah Burke-Spolaor🇺🇸 · J. Andrew Casey-Clyde🇺🇸 and 93 other authors

    The NANOGrav 15-year data provides compelling evidence for a stochastic gravitational-wave (GW) background at nanohertz frequencies. The simplest model-independent approach to characterizing the frequency spectrum of this signal consists in a simple power-law fit involving two parameters: an amplitude A and a spectral index \gamma. In this paper, we consider the next logical step beyond this minimal spectral model, allowing for a running (i.e., logarithmic frequency dependence) of the spectral index, \gamma_run(f) = \gamma + \beta \ln(f/f_ref). We fit this running-power-law (RPL) model to the NANOGrav 15-year data and perform a Bayesian model comparison with the minimal constant-power-law (CPL) model, which results in a 95% credible interval for the parameter \beta consistent with no running, \beta \in [-0.80,2.96], and an inconclusive Bayes factor, B(RPL vs. CPL) = 0.69 +- 0.01. We thus conclude that, at present, the minimal CPL model still suffices to adequately describe the NANOGrav signal; however, future data sets may well lead to a measurement of nonzero \beta. Finally, we interpret the RPL model as a description of primordial GWs generated during cosmic inflation, which allows us to combine our results with upper limits from big-bang nucleosynthesis, the cosmic microwave background, and LIGO-Virgo-KAGRA.

    ↳ astro-ph.HEastro-ph.COgr-qchep-phApJL(2025)·18 citations
39. 39*

    Electric conductivity of hot and dense nuclear matter

    Joseph Atchison🇺🇸 · Yiding Han🇺🇸 · Frank Geurts🇺🇸

    Transport coefficients play an important role in characterising hot and dense nuclear matter, such as that created in ultra-relativistic heavy-ion collisions (URHIC). In the present work we calculate the electric conductivity of hot and dense hadronic matter by extracting it from the electromagnetic spectral function, through its zero energy limit at vanishing 3-momentum. We utilise the vector dominance model (VDM), in which the photon couples to hadronic currents predominantly through the $\rho$ meson. Therefore, we use hadronic many-body theory to calculate the $\rho$-meson's self-energy in hot and dense hadronic matter, by dressing its pion cloud with $\pi$-$\rho$, $\pi$-$\sigma$, $\pi$-$K$, N-hole, and $\Delta$-hole loops. We then introduce vertex corrections to maintain gauge invariance. Finally, we analyze the low-energy transport peak as a function of temperature and baryon chemical potential, and extract the conductivity along a proposed phase transition line.

    ↳ nucl-thhep-phPLB(2024)·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.