Mon·Jan 6, 2025Monday·January 6, 2025

1. 01*

   Forward dijet and vector meson production at the LHC

   C. Royon🇺🇸 · J. Penttala🇺🇸

   We first describe the predictions concerning jet production in the very forward region, especially in the FOCAL kinematic region of the ALICE collaboration at CERN as a test of saturation. We also compare vector meson production cross sections at the LHC in Pb Pb and p Pb collisions with the Balitsky Fadin Kuraev Lipatov and the Balitsky Kovchegov evolution equations and data favor the observation of saturation at the LHC.

   hep-phhep-exnucl-exnucl-thPoS(2025)·0 citations
2. 02*

   Gravitational Wave Mountains: current-carrying domain walls

   Anish Ghoshal🇵🇱 · Yu Hamada🇩🇪

   Domain wall (DW) networks may have formed in the early universe following the spontaneous breaking of a discrete symmetry. Notably, several particle physics models predict the existence of current-carrying DWs, which can capture and store particles as zero modes on it. In this study, we demonstrate that gravitational waves (GWs) generated by current-carrying DWs with fermionic zeromodes exhibit a novel feature: an additional peak in the GW spectrum resembling mountains, arising from metastable topological remnants, which we term ``spherons.'' This distinct signature could be detectable in upcoming GW observatories such as LISA and ET. The results suggest that DW networks in beyond Standard Model scenarios could emit GW signals that are significantly stronger and with greater detectability than previously expected.

   hep-phastro-ph.COhep-thPRD(2025)·6 citations
3. 03*

   Heavy quark suppression and anisotropic flow at intermediate momentum

   Juhee Hong🇰🇷

   In an intermediate-momentum regime where mass effects are significant, heavy quark suppression and anisotropic flow are computed to investigate the transition between the collisional and radiative energy loss. Based on the collision kernel for diffusion, elastic scattering and semi-collinear gluon-bremsstrahlung can be consistently incorporated into a Boltzmann equation that involves the heavy quark diffusion coefficient. Using the running coupling constant and the diffusion coefficient constrained by lattice QCD data, the collisional and radiative energy-loss contributions to the $R_{AA}$ and $v_2$ are studied in hydrodynamically expanding thermal media. The evolution of the observables, the bulk flow effect, and the dependence on mass and centrality are discussed in noncentral heavy-ion collisions.

   hep-phnucl-thPRC(2025)·7 citations
4. 04*

   On the pole trajectory of the subthreshold negative parity nucleon with varying pion masses

   Qu-Zhi Li🇨🇳 · Zhiguang Xiao🇨🇳 · Han-Qing Zheng🇨🇳

   We study the pole trajectory of the recently established subthreshold negative parity nucleon pole, namely the $N^{\ast }(920)$, with varying pion masses, in the scheme of linear $\sigma$ model with nucleons using the $N/D$ unitarization method. We find that as the pion mass increases, the pole moves toward the real axis. For larger pion masses, at tree level, the pole falls to a specific point on $u$-channel cut and crosses to the adjacent Riemann sheet defined by the logarithmic $u$ channel cut. At one-loop level, the pole does not meet the $u$-cut up to $m_{\pi }=0.36$GeV. We also re-examined the $\sigma$ pole trajectory and find it in good agreement with Roy equation analysis result.

   hep-phhep-latnucl-thCPC(2025)·4 citations
5. 05*

   Confining potential in holographic bottom-up QCD from WKB

   Miguel Angel Martin Contreras🇨🇳 · Mitsutoshi Fujita🇨🇳 · Alfredo Vega🇨🇱

   By using the \emph{Rydberg--Klein--Rees} (RKR) formulas to solve the inverse Schrödinger problem, we found a confining bottom-up potential from a given eigenvalue spectrum. To illustrate this methodology, we consider the vector meson spectrum derived in the D3/D7 system as input data to derive the corresponding bottom-up confining potential that resembles the geometric structure of the so-called hardwall model. We compute some properties for this new bottom-up model, including the thermal deconfinement phase transition, the $\rho$ radial Regge trajectory, and the configurational entropy.

   hep-phNPB(2026)·3 citations
6. 06*

   Stueckelberg field and Cosmology

   T R Govindarajan🇮🇳

   Stueckelberg introduced an axion like scalar field to provide mass to the gauge electromagnetic field without breaking gauge invariance. This can be considered as a precursor to the spontaneously broken abelian Higgs model. We will consider its role in cosmology to provide a novel candidate to the dark matter question. In addition its implications to deeper issues will be pointed out.

   hep-phgr-qchep-th0 citations
7. 07*

   Systematic analysis of the mass spectra of triply heavy baryons

   Guo-Liang Yu🇨🇳 · Zhen-Yu Li🇨🇳 · Zhi-Gang Wang🇨🇳 · Ze Zhou🇨🇳

   The mass spectra, root mean square (r.m.s.) radii and radial density distributions of ${\Omega }_{ccb}$ and ${\Omega }_{bbc}$ baryons are firstly analyzed in the present work. The calculations are carried out in the frame work of relativized quark model, where the baryon is regarded as a real three-quark system. Our results show that the excited energy of charmed-bottom triply baryons are always associated with heavier quark. This means the lowest state of ${\Omega }_{ccb}$ baryon is dominated by the $\lambda$-mode, however, the dominant orbital excitation for ${\Omega }_{bbc}$ baryon is $\rho$-mode. In addition, the influence of configuration mixing on mass spectrum, which is induced by different angular momentum assignments, is also analyzed. It shows that energy of the lowest state will be further lowered by this mixing effect. According to this conclusion, we systematically analyze the mass spectra of the ground and excited states($1S\sim 4S$, $1P\sim 4P$, $1D\sim 4D$, $1F\sim 4F$ and $1G\sim 4G$) of ${\Omega }_{ccb}$, ${\Omega }_{bbc}$, ${\Omega }_{ccc}$ and ${\Omega }_{bbb}$ baryons. Finally, with the predicated mass spectra, the Regge trajectories of these heavy baryons in the ($J$,$M^2$) plane are constructed.

   hep-phEPJC(2025)·9 citations
8. 08*

   Complete function space for planar two-loop six-particle scattering amplitudes

   Johannes Henn🇩🇪 · Antonela Matijašić🇩🇪 · Julian Miczajka🇩🇪 · Tiziano Peraro🇮🇹 · Yingxuan Xu🇩🇪 · Yang Zhang🇨🇳

   We derive the full system of canonical differential equations for all planar two-loop massless six-particle master integrals, and determine analytically the boundary conditions. This fully specifies the solutions, which may be written as Chen iterated integrals. We argue that this is sufficient information for evaluating any scattering amplitude in four dimensions up to the finite part. We support this claim by reducing, for the most complicated integral topologies, integrals with typical Yang-Mills numerators. We use the analytic solutions to the differential equations, together with dihedral symmetry, to provide the full solution space relevant for two-loop six-particle computations. This includes the relevant function alphabet, as well as the independent set of iterated integrals up to weight four. We also provide the answer for all master integrals in terms of iterated integrals that can be readily evaluated numerically. As a proof of concept, we provide a numerical implementation that evaluates the integrals in part of the Euclidean region, and validate this against numerical evaluation of the Feynman integrals. Our result removes the bottleneck of Feynman integral evaluation, paving the way to future analytic evaluations of six-particle scattering amplitudes.

   hep-phhep-thPRL(2025)·33 citations
9. 09*

   Constraining eV-scale axion-like particle dark matter: insights from the M87 Galaxy

   Arpan Kar🇫🇷 · Sourov Roy🇮🇳 · Pratick Sarkar🇮🇳

   Axion-like particles (ALPs) can account for the observed dark matter (DM) of the Universe and if their masses are at the eV scale, they can decay into infrared, optical and ultraviolet photons with a decay lifetime larger than the age of the Universe.We analyze multi-wavelength data obtained from the central region of Messier 87 (M87) galaxy by several telescopes, such as, Swift, Astrosat, Kanata, Spitzer and International Ultraviolet Explorer in the infrared to ultraviolet frequencies ($\sim 2\times 10^{14}\mathrm{Hz}-3\times 10^{15}$ Hz), to constrain the narrow emission lines indicative of the eV scale ALP DM decay. We derive constraints on the ALP coupling to two photons ($g_{a\gamma \gamma }$) for ALP mass range $2\mathrm{eV}\lesssim m_a\lesssim 20\mathrm{eV}$, assuming ALPs form the DM in the M87 halo. We find that our bounds on ALP-two-photon coupling can become stronger than the existing ones by an order of magnitude in the ALP mass range $8\mathrm{eV}\lesssim m_a\lesssim 20\mathrm{eV}$.

   hep-phastro-ph.HEJCAP(2025)·8 citations
10. 10*

    QCD Phase Diagram and Astrophysical Implications

    Kenji Fukushima🇯🇵

    I make a brief review about the QCD phases and the equation of state inferred from the neutron star data. Along the temperature axis at low baryon density, the QCD phase transition is a smooth crossover, and it is a natural extension of our imagination to postulate a similar crossover along the density axis at low temperature. Even without phase transitions, the inferred thermodynamic properties of neutron star matter turn out to be highly nontrivial already at twice of the nuclear saturation density. I also give some discussions about the substantiation of quark matter by means of the gravitational wave signals including the multi-messenger prospect.

    hep-phastro-ph.HEnucl-thJ.Subatomic Part.Cosmol.(2025)·21 citations
11. 11*

    LINE: Loop Integrals Numerical Evaluation

    Renato Maria Prisco🇮🇹 · Jonathan Ronca🇮🇹 · Francesco Tramontano🇮🇹

    We present methods for the numerical evaluation of the master integrals that appear in the calculation of scattering amplitudes at higher order in perturbative quantum field theory. We follow the general strategy of solving first-order ordinary differential equations through series expansion. We have collected these procedures in an open source computer program that we dub \Line{}. Boundary conditions can be provided by the user or computed internally using the method of expansion by regions. Illustrative examples are also given.

    hep-phhep-thJHEP(2025)·36 citations
12. 12*

    Enabling Strong Neutrino Self-interaction with an Unparticle Mediator

    Saeid Foroughi-Abari🇨🇦 · Kevin J. Kelly🇺🇸 · Mudit Rai🇺🇸 · Yue Zhang🇨🇦

    Recent explorations of the cosmic microwave background and the large-scale structure of the universe have indicated a preference for sizable neutrino self-interactions, much stronger than what the Standard Model offers. When interpreted in the context of simple particle-physics models with a light, neutrinophilic scalar mediator, some of the hints are already in tension with the combination of terrestrial, astrophysical and cosmological constraints. We take a novel approach by considering neutrino self-interactions through a mediator with a smooth, continuous, spectral density function. We consider Georgi's unparticle with a mass gap as a concrete example and point out two useful effects for mitigating two leading constraints. 1) The Unparticle is ``broadband'' -- it occupies a wide range of masses which allows it to pass the early universe constraint on effective number of extra neutrinos ($\Delta N_{eff.}$) even if the mass gap lies below the MeV scale. 2) Scattering involving unparticles is less resonant -- which lifts the constraint set by IceCube based on a recent measurement of ultra-high-energy cosmogenic neutrinos. Our analysis shows that an unparticle mediator can open up ample parameter space for strong neutrino self-interactions of interest to cosmology and serves a well-motivated target for upcoming experiments.

    hep-phastro-ph.COastro-ph.HEhep-exPRL(2025)·10 citations
13. 13*

    Studying the Strangeness $D$-Term in Hall C via Exclusive $\varphi$ Electroproduction

    H. T. Klest🇺🇸 · S. Joosten🇺🇸 · H. Szumila-Vance🇺🇸 · W. Armstrong🇺🇸 · F. A. Flor🇺🇸 · B. Kim🇺🇸 · M. H. Kim🇺🇸 · V. Klimenko🇺🇸 · S. Lee🇺🇸 · Z.-E. Meziani🇺🇸 · C. Peng🇺🇸 · N. Pilleux🇺🇸 and 47 other authors

    We propose a measurement of exclusive electroproduction of $\varphi$ mesons near threshold in Hall C. We will measure the |t|-dependence of the exclusive $\varphi$ electroproduction cross section, which has recently been proposed as an observable sensitive to the strangeness $D$-term. The contribution of strangeness to the total $D$-term is presently unknown, with different arguments favoring $D_s$ being large, being small, or even having opposite sign from the total $D$-term. Our exploratory measurement is designed to distinguish between these hypotheses. If $D_s$ turns out to be small, $\varphi$ electroproduction can be used to study the gluon $D$-term. In addition, this dataset will allow us to perform measurements of other exclusive meson final states, including the first measurement of ${\eta }^{\prime }$ electroproduction and multi-differential measurements of $\eta$ and $\omega$ electroproduction.

    ↳ nucl-exhep-exhep-ph5 citations
14. 14*

    Very high energy cosmic ray particles from the Kerr black hole at the galaxy center

    Orlando Panella🇮🇹 · Simone Pacetti🇮🇹 · Giorgio Immirzi🇮🇹 · Yogendra N. Srivastava🇮🇹

    Conventional general relativity supplies the notion of a vacuum tension and thus a maximum force $F_{max}=c^4/4G\approx 3\times 10^{43}$ Newtons, that is realized for a black hole. In conjunction with the Wilson area rule, we are thus led to the surface confinement of the mass of a black hole analogous to the surface confinement of quarks. The central result of our paper is that PeV scale protons exist on the surface of a Kerr black hole residing at our galactic center that is in concert with the HAWC Collaboration result of a PeVatron at the galactic center.

    ↳ astro-ph.HEhep-ph0 citations
15. 15*

    Search for continuous gravitational wave signals from luminous dark photon superradiance clouds with LVK O3 observations

    Lorenzo Mirasola🇮🇹 · Cristina Mondino🇨🇦 · Francesco Amicucci🇮🇹 · Nils Siemonsen🇺🇸 · Cristiano Palomba🇮🇹 · Sabrina D'Antonio🇮🇹 · Paola Leaci🇮🇹 · Luca D'Onofrio🇮🇹 · Pia Astone🇮🇹 · Daniel Egana-Ugrinovic🇨🇦 · Junwu Huang🇨🇦 · Masha Baryakhtar🇺🇸 · William E. East🇨🇦

    Superradiance clouds of kinetically-mixed dark photons around spinning black holes can produce observable multi-messenger electromagnetic and gravitational wave signals. The cloud generates electric fields of up to a Teravolt-per-meter, which lead to a cascade production of charged particles, yielding a turbulent quasi-equilibrium plasma around the black hole, and resulting in electromagnetic fluxes ranging from supernova to pulsar-like luminosities. For stellar mass black holes, such systems resemble millisecond pulsars and are expected to emit pulsating radio waves and continuous gravitational waves (CWs) within the LIGO-Virgo-KAGRA (LVK) sensitivity band. We select 44 sources with approximately coincident frequencies or positive frequency drifts from existing pulsar catalogs as potential candidates of long-lasting superradiance clouds around old galactic black holes. For a subset of 34 sources that are well measured and have not been previously targeted, we perform the first search for CW emission in LVK data from the third observing run. We find no evidence of a CW signal and place 95% confidence level upper limits on the emitted strain amplitude. We interpret these results, together with limits from previous searches, in terms of the underlying dark photon theory by performing an analysis of the expected signals from superradiance clouds from galactic black holes. We find that, even for moderately spinning black holes, the absence of an observed CW signal disfavors a discrete set of dark photon masses between about $10^{-13}$ $\mathrm{eV}/{\mathrm{c}}^2$ and $10^{-12}$ $\mathrm{eV}/{\mathrm{c}}^2$ and kinetic mixing couplings in the range of $10^{-9}$-$10^{-7}$, subject to assumptions about the properties of the black hole population and the cloud's electromagnetic emission.

    ↳ gr-qcastro-ph.HEhep-phPRD(2025)·12 citations
16. 16*

    Parity-doubled nucleons can rapidly cool neutron stars

    Liam Brodie🇺🇸 · Robert D. Pisarski🇺🇸

    In confined hadronic matter, the spontaneous breaking and restoration of chiral symmetry can be described by considering nucleons, $N_{+}(939)$, and excited states of opposite parity, $N_{-}(1535)$. In a cold, dense hadronic phase where chiral symmetry remains spontaneously broken, direct Urca decay processes involving the $N_{-}$ are possible, e.g. $N_{-}\to N_{+}+e^{-}+{\bar{\nu }}_e$. We show that at low temperature and moderate densities, because the $N_{-}$ is much heavier than the $N_{+}$, such cooling dominates over standard $N_{+}$ direct Urca processes. This provides a strong astrophysical signature of the pattern of chiral symmetry restoration in neutron stars.

    ↳ nucl-thastro-ph.HEhep-phPRL(2025)·4 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.