Thu·Jan 23, 2025Thursday·January 23, 2025

1. 01*

   Extending the Bridge Connecting Chiral Lagrangians and QCD Gaussian Sum-Rules for Low-Energy Hadronic Physics

   Amir H. Fariborz🇺🇸 · J. Ho🇺🇸 · T.G. Steele🇨🇦

   It has previously been demonstrated that the mesonic fields in chiral Lagrangians can be related to the quark-level operators of QCD sum-rules via energy-independent (constant) scale factor matrices constrained by chiral symmetry. This leads to universal scale factors for each type of chiral nonet related to quark-antiquark ($q\bar{q}$) operators and four-quark ($qq\bar{q}\bar{q}$) operators. Motivated by these successful demonstrations of scale-factor universality for the $K_0^{\ast }$ isodoublet and $a_0$ isotriplet scalar mesons, a revised Gaussian QCD sum-rule methodology is developed that enables the extension to higher-dimensional isospin sectors, including the possibility of mixing with glueball components. Moreover, to extract non-perturbative information about a resonance stemming from the final state interactions of its decay products, a background-resonance interference approximation is developed and shown to provide an excellent description of both $\pi K$ scattering amplitude data and $\pi \eta$ scattering calculations. This background-resonance interference approximation inspires new resonance models as ingredients in the scale-factor analysis connecting chiral Lagrangians and QCD Gaussian sum-rules. Using the revised Gaussian QCD sum-rule methodology, key properties of the scale factors are examined for the $K_0^{\ast }$ isodoublet and $a_0$ isotriplet scalar mesons for a sequence of increasingly sophisticated resonance models. Gaussian sum-rules are demonstrated to have sufficient resolution to distinguish between different resonance models, and it is shown that the background-resonance interference approximation not only describes $\{\pi K,\pi \eta \}$ scattering, but leads to the best universality and energy-independence properties of the scale factors.

   hep-phPRD(2025)·3 citations
2. 02*

   Constraints on flavor-dependent long-range interactions of high-energy astrophysical neutrinos

   Sanjib Kumar Agarwalla🇮🇳 · Mauricio Bustamante🇩🇰 · Sudipta Das🇮🇳 · Ashish Narang🇮🇳

   Astrophysical neutrinos with energy in the TeV-PeV range traverse megaparsecs (Mpc) to gigaparsecs (Gpc) scale distances before they reach the Earth. Tiny physics effects that get accumulated over these large propagation paths during their journey may become observable at the detector. If there is some new interaction between neutrinos and the background matter, that can potentially affect the propagation of the astrophysical neutrinos. One such possible case is the flavor-dependent long-range interaction of neutrinos, which can affect the standard neutrino flavor transition, modifying the flavor composition of the astrophysical neutrinos at Earth. Using the present-day and future projection of the flavor-composition measurements of IceCube and IceCube-Gen2 along with the present and future measurement of the oscillation parameters, we explore the sensitivity of these experiments to probe long-range neutrino interaction with matter.

   hep-phastro-ph.HEhep-ex0 citations
3. 03*

   Laser induced Compton Scattering to Dark Matter in Effective Field Theory

   Kai Ma🇨🇳 · Tong Li🇨🇳

   The detection of light dark matter (DM) is a longstanding challenge in terrestrial experiments. High-intensity facility of an intense electromagnetic field may provide a plausible strategy to study strong-field particle physics and search for light DM. In this work, we propose to search for light DM particle through the nonlinear Compton scattering in the presence of a high-intense laser field. An ultra-relativistic electron beam collides with an intense laser pulse of a number of optical photons and then decays to a pair of DM particles. We take into account the Dirac-type fermionic DM in leptophilic scenario and the DM-electron interactions in the framework of effective field theory. The decay rates of electron to a DM pair are calculated for effective DM operators of different bilinear products. We show the sensitivities of laser induced Compton scattering to the effective cutoff scale for DM lighter than 1 MeV and compare with direct detection experiments.

   hep-phJHEP(2025)·3 citations
4. 04*

   An introduction to effective potential methods in field theory

   Isabella Masina🇮🇹 · Mariano Quiros🇪🇸

   In this chapter we give a pedagogical introduction to effective potential methods in field theories. We first review the general functional methods leading to the concept of effective action and effective potential. Focusing on the effective potential we review the methods to compute radiative contributions, starting from the original 1973 seminal paper by Sidney Coleman and Erick Weinberg on one-loop corrections, along with its improvement by the renormalization group equations, as well as some basic results from thermal field theory, including the one-loop thermal corrections to the effective potential. We concentrate on some physical applications of the effective potential: i) the possibility of spontaneous symmetry breaking by radiative corrections, ii) the metastability of the electroweak vacuum in the Standard Model, and iii) the relevance of quantum effects in the dynamics of Higgs inflation. We then apply the previous results to cosmological phase transitions in the early universe and the possibility of generating a stochastic background of gravitational waves as well as primordial black holes.

   hep-phhep-th5 citations
5. 05*

   Searching for compact pentaquark state within the bag model framework

   Wen-Nian Liu🇨🇳 · Wen-Xuan Zhang🇨🇳 · Fu-Quan Dou🇨🇳

   The search for the compact limit of multi-quark states is a challenging issue. Within the framework of the MIT bag model, we propose an effective limit bag radius of $R_c=5.615{\text{GeV}}^{-1}$(or $1.11\text{fm}$) for bound states . When the bag radius of a hadron falls below this value, the bag binding energy satisfies $E_B<0$, indicating that the system has a compact intention. We consider various combinations of different numbers and ratios of heavy and light quarks, indicating that the bag radius of hadrons depending on the number of quarks is suppressed by the presence of heavy quarks. Focusing on five-quark combinations, we find that the average bag radius of $nncc\bar{c}$ is below the threshold $R_c$. We take into account color-magnetic interactions and calculate the mass, magnetic moment, binding energy, and relative strong decay width for the $nnQQ\bar{Q}$ system. We show that the binding energies of most states in the flavor combination $nncc\bar{c}$ are approximately $-20\text{MeV}$, whereas states involving bottom quarks have binding energies around $-120\text{MeV}$, with some decay widths suppressed by the decay constant. Additionally, the $nQQQ\bar{Q}$ system exhibits even deeper binding. Our results support the compact intention of $nnQQ\bar{Q}$ and suggest that the $nQQQ\bar{Q}$ configuration demonstrates even stronger compactness.

   hep-phPRD(2025)·6 citations
6. 06*

   Single spin asymmetry in forward $pA$ collisions from Pomeron-Odderon interference

   Sanjin Benić🇭🇷 · Eric Andreas Vivoda🇭🇷

   Working in the hybrid framework of the high energy $pA$ collisions we identify a new contribution to transverse single spin asymmetry (SSA). The phase necessary for the SSA is provided by the Pomeron-Odderon interference in the dense nuclear target. The complete formula for the $pA\to hX$ polarized cross section also contains the transversity distribution for the polarized projectile as well as the real part of the twist-3 fragmentation function. We numerically estimate the asymmetry $A_N$ and its nuclear dependence. Based on a model computation we find that $A_N$ can be a percent level in the forward and low-$P_{h\perp }$ region. For large nuclei we find significant suppression, with $A_N\propto A^{-7/6}$ parametrically. As a notable feature we find a node of $A_N$ as a function of the $P_{h\perp }$ around the values of the initial saturation scale that could be used to test this mechanism experimentally.

   hep-phPRD(2025)·4 citations
7. 07*

   Simultaneous description of high density QCD matter in heavy ion collisions and neutron star observations

   Jan Steinheimer🇩🇪 · Manjunath Omana Kuttan🇩🇪 · Tom Reichert🇩🇪 · Yasushi Nara🇯🇵 · Marcus Bleicher🇩🇪

   A combined constraint on the QCD equation of state, at high densities, from connecting neutron star observations to data from heavy ion reactions is presented. We use the Chiral Mean Field Model which can describe neutron star and iso-spin symmetric matter and allows the consistent calculation of the density and momentum dependent potentials of baryons which are then implemented in the UrQMD transport model. In contrast to previous studies, the same equation of state constrained from neutron star properties is also able to describe experimental observables in heavy ion reactions at the HADES experiment. Unlike many other approaches our results are not constraint to densities up to nuclear saturation or perturbative results which allows a continuous description of the equation of state over a large range in baryon density.

   hep-phnucl-thPLB(2025)·22 citations
8. 08*

   Investigation of ${\Lambda }_c\to (\Lambda ,n){\ell }^{+}{\nu }_{\ell }$ Decays in Standard Model and Beyond

   Zhi-Hua Zhang🇨🇳 · Ying Li🇨🇳

   In this work, we study the decays ${\Lambda }_c\to (\Lambda ,n){\ell }^{+}{\nu }_{\ell }$ ($\ell =\mu ,e$) within a model-independent framework. We calculate the helicity amplitudes for all possible four-fermion operators, including the interactions between different new physics (NP) operators. The form factors for the ${\Lambda }_c\to (\Lambda ,n)$ transitions are taken from lattice QCD calculations. We present detailed results for the branching fractions and other key observables. Although our results are generally consistent with previous studies, we find that the predicted central values for the branching fractions are approximately $10\%$ larger than the experimental measurements. Additionally, we explore the potential impacts of NP, focusing particularly on the scenario in which NP particles couple exclusively to the muon. Using Wilson coefficients fitted from $D$ and $D_s$ meson decays, we examine NP effects in the ${\Lambda }_c\to (\Lambda ,n){\mu }^{+}{\nu }_{\mu }$ decay channels. It is found that although most potential contributions of NP are obscured by the uncertainties inherent in both theory and experiment, the right-handed scalar operator could suppress the branching fraction of ${\Lambda }_c\to (\Lambda ,n){\mu }^{+}{\nu }_{\mu }$ by up to $10\%$. We also highlight that the ratio of the forward-backward asymmetry in the ${\Lambda }_c\to (\Lambda ,n){\mu }^{+}{\nu }_{\mu }$ decay to that in the ${\Lambda }_c\to (\Lambda ,n)e^{+}{\nu }_e$ decay provides a novel probe for NP, as it is less sensitive to hadronic uncertainties and is largely unaffected by current NP operators. All of our results can be tested in ongoing experiments such as BESIII, Belle-II, and LHCb, as well as in future high-energy facilities like the Super Tau-Charm Factory (STCF) and the Circular Electron Positron Collider (CEPC).

   hep-phhep-exPRD(2025)·7 citations
9. 09*

   Electromagnetic leptogenesis with light-heavy sterile neutrinos

   Debasish Borah🇮🇳 · Arnab Dasgupta🇺🇸

   We propose a novel leptogenesis scenario utilising the two-body decay of heavy right handed neutrino (RHN) via the electromagnetic dipole operator. While the requirement of the standard model (SM) gauge invariance requires such dipole operator only at dimension-6 forcing the generation of non-zero CP asymmetry from three-body decay with two-loop corrections, we write down dimension-5 dipole operators involving heavy RHN $N_R$ and its lighter counterpart ${\nu }_R$. This allows the generation of lepton asymmetry in ${\nu }_R$ from two-body decay of heavy RHN which later gets transferred to left handed leptons via sizeable Yukawa coupling with a neutrinophilic Higgs doublet. The asymmetry in left handed leptons is then converted to baryon asymmetry via electroweak sphalerons. The lepton number violation by heavy RHN also induces a one-loop Majorana mass of ${\nu }_R$ rendering the light neutrinos to be Majorana fermions. While smallness of the Majorana mass of ${\nu }_R$ prevents additional sources or washout of lepton asymmetry, it also constrains the scale of leptogenesis. For $\mathcal{O}(10)$ TeV scale leptogenesis, this leads to additional sterile neutrinos lighter than a few keV with interesting implications for a variety of observables including neutrino oscillation, warm dark matter as well as effective degrees of freedom within reach of future cosmic microwave background experiments. Additionally, heavy RHN can lead to observable monochromatic photon signatures at terrestrial experiments.

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

    Neutrinophilic $\mathbf{\Lambda }$CDM Extension for EMPRESS, DESI and Hubble Tension

    Yuan-Zhen Li🇨🇳 · Jiang-Hao Yu🇨🇳

    A number of recent cosmological observations have indicated the presence of new physics beyond the $\mathbf{\Lambda }$CDM model. Combining observations from EMPRESS on helium abundance and DESI on baryon acoustic oscillations with Hubble tension, we show that all of them can be explained concurrently with a extension of the $\mathbf{\Lambda }$CDM model with primordial neutrino asymmetry ${\xi }_{\nu }$ and additional contribution to the effective number of neutrinos $\delta N_{\mathrm{eff}}$. Based on the accurate treatments of neutrino decoupling and BBN processes, we present state-of-the-art constraints on neutrino asymmetry for the fixed or varying $N_{\mathrm{eff}}$. Comparing different extensions of the $\mathbf{\Lambda }$CDM model, we show that the neutrinophilic $\mathbf{\Lambda }$CDM extension with ${\xi }_{\nu }=0.056\pm 0.017$ and $\delta N_{\mathrm{eff}}=0.41\pm 0.16$ is preferred by current observations, while the Hubble tension in this model is also alleviated to be $2.2\sigma$.

    hep-phastro-ph.CO4 citations
11. 11*

    Axion framework with color-mediated Dirac neutrino masses

    A. Batra🇵🇹 · H.B. Câmara🇵🇹 · F.R. Joaquim🇵🇹 · N. Nath🇮🇳 · R. Srivastava🇮🇳 · J.W.F. Valle🇪🇸

    We propose a KSVZ-type axion framework in which vector-like quarks (VLQ) and colored scalars generate Dirac neutrino masses radiatively. The global Peccei-Quinn symmetry (under which the exotic fermions are charged) addresses the strong CP problem and ensures the Dirac nature of neutrinos. The axion also accounts for the observed cosmological dark matter. We systematically explore all viable VLQ representations. Depending on the specific scenario, the framework predicts distinct axion-to-photon couplings, testable through haloscope and helioscope experiments, as well as potentially significant flavor-violating quark-axion interactions.

    hep-phPLB(2025)·11 citations
12. 12*

    Asymptotic Freedom in Parton Language: the Birth of Perturbative QCD

    Stefano Forte🇮🇹

    I review the contributions of Giorgio Parisi to perturbative QCD. Concentrated in a decade, they mark the transition of the theory of strong interactions from a set of loosely connected ideas based on models, to a quantum field theory that is now an integral part of the standard model of fundamental interactions. Parisi's contributions have established at a very early stage ideas, methods and tools that are now standard, and in several cases anticipated results that only became prominent in the XXIst century.

    hep-phhep-thphysics.hist-ph5 citations
13. 13*

    Searching for Dark Matter with MeVCube

    Akash Kumar Saha🇮🇳

    CubeSat technology is an emerging alternative to large-scale space telescopes due to its short development time and cost-effectiveness. MeVCube is a proposed CubeSat mission to study the least explored MeV gamma-ray sky, also known as the `MeV gap'. Besides being sensitive to a plethora of astrophysical phenomena, MeVCube can also be important in the hunt for dark matter. If dark matter is made up of evaporating primordial black holes, then it can produce photons in the sensitivity range of MeVCube. Besides, particle dark matter can also decay or annihilate to produce final state gamma-ray photons. We perform the first comprehensive study of dark matter discovery potential of a near-future MeVCube CubeSat mission. In all cases, we find that MeVCube will have much better discovery reach compared to existing limits in the parameter space. This may be an important step towards discovering dark matter through its non-gravitational interactions.

    hep-phastro-ph.COastro-ph.HEhep-exPRD(2025)·9 citations
14. 14*

    Fast interpolation grids for the Drell-Yan process

    Juan Cruz-Martinez🇨🇭 · Alexander Huss🇨🇭 · Christopher Schwan🇩🇪

    Modern analyses of experimental data from hadron colliders rely on theory predictions at high orders in perturbation theory and a variety of input settings. Interpolation grids facilitate an almost instant re-evaluation of theory predictions for different input parton distributions functions (PDFs) or scale settings and are thus indispensable in the study of the parton content of the proton. While interpolation grids at next-to-next-to-leading order (NNLO) exist for some key processes relevant for PDF determinations, a notable exception is the Drell-Yan process that constitutes the production of electroweak gauge bosons at hadron colliders and provides important constraints on the quark content of the proton. To address this gap, we report on a new interface between the parton-level Monte Carlo generator NNLOJET and the interpolation grid library PINEAPPL and demonstrate its use for the Drell-Yan process. Accompanying this note, we release Drell-Yan grids covering a wide range of measurements that commonly enter global determinations of PDFs. We use the grids to study accidental cancellation between partonic channels at NNLO and inspect the validity of a K-factor approximation that was widely employed previously.

    hep-phEPJC(2025)·7 citations
15. 15*

    Extending Israel-Stewart theory: Causal bulk viscosity at large gradients

    Lorenzo Gavassino🇺🇸

    We present a class of relativistic fluid models for cold and dense matter with bulk viscosity, whose equilibrium equation of state is polytropic. These models reduce to Israel-Stewart theory for small values of the viscous stress $\Pi$. However, when $\Pi$ becomes comparable to the equilibrium pressure $P$, the evolution equations "adjust" to prevent the onset of far-from-equilibrium pathologies that would otherwise plague Israel-Stewart. Specifically, the equations of motion remain symmetric hyperbolic and causal at all times along any continuously differentiable flow, and across the whole thermodynamic state space. This means that, no matter how fast the fluid expands or contracts, the hydrodynamic equations are always well-behaved (away from singularities). The second law of thermodynamics is enforced exactly. Near equilibrium, these models can accommodate an arbitrarily complicated dependence of the bulk viscosity coefficient $\zeta$ on both density and temperature.

    ↳ gr-qcastro-ph.HEhep-phnucl-thPRD(2025)·1 citation
16. 16*

    On Equation of State of Dark Matter around Massive Black Holes

    Zhong-Ming Xie · Yong Tang

    The nature of Dark Matter (DM) remains mysterious despite the substantial evidence from astrophysical and cosmological observations. While the majority of DM in our universe is non-relativistic, collisionless and its equation of state (EoS) is approximately pressureless $p\simeq 0$, DM becomes relativistic near the massive black holes in galactic center. Yet its EoS is seldom discussed in the relativistic regime. Here we initially explore the possible equation of state for DM in the vicinity of Schwarzschild black holes. We work in a spherical and quasi-static background spacetime, and describe DM as a perfect fluid in equilibrium. Through numerically solving the TOV equations with physical boundary conditions, we show that DM can have static profiles near black holes and its pressure should be negative in order to support the viable density profiles $\rho$. We illustrate with two simple general equations of state, namely the power law $p\propto {\rho }^{\gamma }$ and the radius-dependent $p\propto r\cdot \rho$, and compare them with the observations of the Milky Way. Our findings provide insights into the model-building of DM, which should incorporate the possibility of negative pressure in the relativistic regime around black holes.

    ↳ gr-qcastro-ph.GAhep-phSCPMA(2026)·6 citations
17. 17*

    Semianalytic model for decaying dark matter halos

    Ethan O. Nadler🇺🇸 · Andrew J. Benson🇺🇸

    Decaying dark matter (DDM) affects the evolution of cosmic structure relative to standard cold, collisionless, stable dark matter (CDM). We introduce a new semianalytic model for the effects of two-body DDM on halo structure and subhalo populations. In this scenario, cold parent dark matter particles decay into less massive daughter particles plus dark radiation with a lifetime comparable to the age of the Universe. Our DDM model is implemented in the open-source software $\text{Galacticus}$ and accounts for heating (due to the velocity kicks imparted on daughter particles) and mass loss (due to the parent-daughter mass splitting). We show that decays flatten and reduce the amplitude of halos' inner density profiles. These effects make DDM subhalos susceptible to tidal disruption, which we show yields a mass-dependent suppression of the subhalo mass function relative to CDM. Our predictions for DDM density profiles, velocity dispersion profiles, and subhalo populations are consistent with results from isolated and cosmological DDM N-body simulations. Thus, our model enables efficient and accurate exploration of DDM parameter space and will be useful for deriving constraints from upcoming small-scale structure observations.

    ↳ astro-ph.COhep-phPRD(2025)·4 citations
18. 18*

    Non-relativistic QCD Study of Excited Bottomonia at Finite Temperatures on a Fine Lattice

    Heng-Tong Ding🇨🇳 · Wei-Ping Huang🇨🇳 · Rasmus Larsen🇩🇪 · Stefan Meinel🇺🇸 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸

    The temperature dependence of bottomonium correlators up to the 3S and 3P excited states are presented in the range $T\simeq 133-250$ MeV. These lattice calculations employ the non-relativistic QCD (NRQCD) approach for bottom quarks on (2+1)-flavor gauge backgrounds, using the highly improved staggered quark (HISQ) action near the physical point. The study utilizes a fine lattice spacing of 0.0493 fm at all temperatures. Extended bottomonium operators are implemented to achieve optimized overlaps with the targeted excited states, enhancing sensitivity to thermal effects. To probe in-medium modifications of excited bottomonia, we extract thermal widths and in-medium masses from bottomonium correlators, parameterizing the spectral function with a Gaussian ansatz. Our results confirm nonzero thermal widths for various bottomonium states as the temperature increases, while no significant mass shifts are observed. Additionally, we check that the in-medium properties of bottomonia are almost not affected by variations in the choice of extended operators.

    ↳ hep-lathep-phnucl-thPoS(2025)·0 citations

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