Tue·Dec 19, 2023Tuesday·December 19, 2023

1. 01*

   Prospects on the Detection of Solar Dark Photons by the International Axion Observatory

   T. O'Shea🇪🇸 · M. Giannotti🇺🇸 · I. G. Irastorza🇪🇸 · L. M. Plasencia🇪🇸 · J. Redondo🇪🇸 · J. Ruz🇪🇸 · J. K. Vogel🇪🇸

   Dark (hidden) photons are widely recognised as well motivated candidates for physics beyond the standard model, and have been invoked for the solution of several outstanding problems, including to account for the dark matter in the universe. In this paper, we consider a simple model for dark photons, which is coupled to ordinary matter only through kinetic mixing with ordinary photons. Within this framework, we calculate the flux of solar dark photons on Earth and revise the potential to detect it with the next generation of axion helioscopes, particularly with the International AXion Observatory (IAXO). This paper extends on previous theoretical analyses in two main ways. Firstly, it includes a more complete analysis of the possible sources of dark photons from the sun, including the contribution of the solar magnetic field and of nuclear processes, and secondly it includes predictions on the parameter space accessible in the gas-filled phase of IAXO.

   hep-phastro-ph.HEastro-ph.SRJCAP(2024)·12 citations
2. 02*

   Quantum to classical parton evolution in the QGP

   João Barata🇺🇸 · Jean-Paul Blaizot🇫🇷 · Yacine Mehtar-Tani🇺🇸

   We study the time evolution of the density matrix of a high energy quark in the presence of a dense QCD background that is modeled as a stochastic Gaussian color field. At late times, we find that only the color singlet component of the quark's reduced density matrix survives the in-medium evolution and that the density matrix becomes asymptotically diagonal in both transverse position and momentum spaces. In addition, we observe an accelerated entropy growth due to the larger phase space being explored by the quark and that the quantum and classical quark entropies converge at late times. We further observe that the quark state loses all memory of the initial condition. Combined with the fact that the reduced density matrix satisfies Boltzmann-diffusion transport, we conclude that the quark reduced density matrix can be interpreted as a classical phase space distribution.

   hep-phEPJ Web Conf.(2024)·0 citations
3. 03*

   Analysis of the vector hidden-charm-hidden-strange tetraquark states with implicit P-waves

   Zhi-Gang Wang🇨🇳

   We take the scalar, pseudoscalar, axialvector, vector and tensor diquarks as the basic building blocks to construct the four-quark currents with implicit P-waves, and investigate the hidden-charm-hidden-strange tetraquark states with the $J^{PC}=1^{--}$ and $1^{-+}$ via the QCD sum rules in a comprehensive and consistent way, and revisit the assignments of the $X/Y$ states, especially the $Y(4500)$, $X(4630)$, $Y(4660)$, $Y(4710)$ and $Y(4790)$, in the tetraquark picture.

   hep-phNPB(2024)·15 citations
4. 04*

   Charmonia in an unquenched quark model

   Qian Deng🇨🇳 · Ru-Hui Ni🇨🇳 · Qi Li🇨🇳 · Xian-Hui Zhong🇨🇳

   In this work, we study the charmonium spectrum within an unquenched quark model including coupled-channel effects. In couple-channel calculations, we include all of the opened charmed meson channels with the once-subtracted method, meanwhile adopt a suppressed factor to soften the hard vertices given by the ${}^3{P}_0$ model in the high momentum region. We obtain a good description of both the masses and widths for the well-established states in the charmonium spectrum. Furthermore, we give predictions for the higher $S$-, $P$- and $D$-wave charmonium states up to mass region of $\sim 5.0$ GeV. The magnitude of mass shifts due to the coupled-channel effects is estimated to be about $10s$ MeV. Although many decay channels are opened for the higher charmonium states, they are relatively narrow states. Their widths scatter in the range of $\sim 10s-100$ MeV. Many charmonium-like states, such as ${\chi }_{c1}(3872)$, ${\chi }_{c1}(4274)$, ${\chi }_{c0}(3915)$, ${\chi }_{c0}(4500)$, ${\chi }_{c0}(4700)$, $X(4160)$, $X(4350)$, $Y(4500)$, and $\psi (4660)$/$Y(4710)$, can be accommodated by the charmonium spectrum when the unquenched coupled-channel effects are carefully considered.

   hep-phhep-exPRD(2024)·42 citations
5. 05*

   Collisional flavor pendula and neutrino quantum thermodynamics

   Lucas Johns🇺🇸 · Santiago Rodriguez🇺🇸

   Neutrinos in core-collapse supernovae and neutron-star mergers are susceptible to flavor instabilities of three kinds: slow, fast, and collisional. Prior work has established mappings of the first two onto abstract mechanical systems in flavor space, respectively named the slow and fast flavor pendula. Here we introduce and analyze the flavor pendulum associated with the third class. We explain our results in terms of the recently developed theory of neutrino quantum thermodynamics. Perhaps our most surprising finding is that there exists a limit in which decoherent interactions drive perfectly coherent flavor conversion.

   hep-phastro-ph.HE13 citations
6. 06*

   Endpoint divergences in inclusive $\bar{B}\to X_s\gamma$

   Tobias Hurth🇩🇪 · Robert Szafron🇺🇸

   The subleading so-called resolved contributions represent the largest uncertainty in the inclusive decay mode $\bar{B}\to X_s\gamma$. However there had been no complete proof of factorization of these subleading contributions. This failure of factorisation can be traced back to endpoint divergences and cured by recently proposed refactorisation techniques.

   hep-phPoS·1 citation
7. 07*

   Gravitational waves from cosmic superstrings and gauge strings

   Danny Marfatia🇺🇸 · Ye-Ling Zhou🇨🇳

   We perform a phenomenological comparison of the gravitational wave (GW) spectrum expected from cosmic gauge string networks and superstring networks comprised of multiple string types. We show how violations of scaling behavior and the evolution of the number of relativistic degrees of freedom in the early Universe affect the GW spectrum. We derive simple analytical expressions for the GW spectrum from superstrings and gauge strings that are valid for all frequencies relevant to pulsar timing arrays (PTAs) and laser interferometers. We analyze the latest data from PTAs and show that superstring networks are consistent with 32 nHz data from NANOGrav, but are excluded by 3.2 nHz data at $3\sigma$ unless the string coupling $g_s<0.2$ or the strings evolve in only about 10% of the volume of the higher-dimensional space. We also point out that while gauge string networks are excluded by NANOGrav-15 data at $3\sigma$, they are completely compatible with EPTA and PPTA data. Finally, we study correlations between GW signals at PTAs and laser interferometers.

   hep-phastro-ph.COgr-qchep-ex+1JHEP(2024)·11 citations
8. 08*

   The 95 GeV Excess in the Georgi-Machacek Model: Single or Twin Peak Resonance

   Amine Ahriche (Sharjah U., UAE)🇦🇪

   In this work, we investigate the possibility to address the excess observed around 95 GeV in the $\gamma \gamma$, $\tau \tau$, and $b\bar{b}$ channels as a scalar resonance(s) within the Georgi-Machacek (GM) model. In our analysis, we find that the excess can be easily accommodated in the channels ($\gamma \gamma$ and $b\bar{b}$) simultaneously, where the 95 GeV candidate is a single peak resonance (SPR) due to a light CP-even scalar. We found that the excess in the $\tau \tau$ channel can be addressed simultaneously with $\gamma \gamma$ and $b\bar{b}$ only if the 95 GeV candidate is a twin peak resonance (TPR), i.e., another CP-odd scalar in addition to the CP-even scalar. We demonstrate that the nature of the 95 GeV scalar resonance candidate (SPR or TPR) can be probed via the properties of its di-$\tau$ decay.

   hep-phhep-exnucl-thPRD(2024)·38 citations
9. 09*

   Migdal-type effect in the dark matter absorption process

   V.A. Dzuba🇦🇺 · V.V. Flambaum🇦🇺 · I.B. Samsonov🇦🇺

   We propose a new mechanism of absorption of dark matter particles in atoms which resembles the Migdal effect of inelastic dark matter scattering. In this process, atom may be ionized upon absorption of a scalar particle through the scalar-nucleon Yukawa-type interaction. The crucial difference from the inelastic dark matter scattering on atoms is that the total energy of the particle, including its rest mass $m{c}^2$-term, is transferred to the electron. As a result, the emitted electron kinetic energy is about six orders in magnitude bigger than that in the dark matter scattering process. This absorption process allows one to probe dark matter particles with a relatively small mass, in the range from 1 to 100 keV, that cannot be detected in the scattering process. It is also possible to detect hypothetical scalar particles emitted from the Sun. We calculate absorption cross sections of this process in Na, Si, Ar, Ge, I, Xe, and Tl target atoms and extract limits on the scalar-nucleon interaction constant from null results of XENONnT experiment.

   hep-phhep-exphysics.atom-phPRD(2024)·6 citations
10. 10*

    Color-octet nonrelativistic QCD matrix elements for heavy quarkonium decays in the refined Gribov-Zwanziger theory

    Hee Sok Chung🇰🇷

    We determine color-octet nonrelativistic QCD matrix elements for quarkonium decays from moments of the two-point correlation function of the QCD field-strength tensor computed in the refined Gribov-Zwanziger theory. We find that a tree-level calculation in the refined Gribov-Zwanziger theory can give a suitable description of the QCD field-strength correlation function at both short and long distances, which leads to moments that are infrared finite and can be properly renormalized. By using the color-octet matrix elements we obtain, we quantitatively improve the nonrelativistic effective field theory description of quarkonium decay rates, especially for the ${\chi }_{QJ}$ and ${\eta }_Q$ states, where $Q=c$ or $b$.

    hep-phPRD(2024)·3 citations
11. 11*

    About the magnitude of the ${\gamma }^{\ast }N\to N(1520)$ transverse amplitudes near $Q^2=0$

    G. Ramalho🇰🇷

    The ${\gamma }^{\ast }N\to N(1520)$ transition has a property that differs from the other low-lying nucleon resonance amplitudes: the magnitude of the transverse helicity amplitudes.The transition helicity amplitudes are defined in terms of square-transfer momentum $q^2$, or $Q^2=-q^2$. Near the photon point ($Q^2=0$) there is a significant difference in the magnitude of the transverse amplitudes: $A_{3/2}$ is very large and $A_{1/2}$ is very small. This atypical behavior contrasts with the relation between the amplitudes at the pseudothreshold [the limit where the nucleon and the $N(1520)$ are both at rest and $Q^2<0$], where $A_{3/2}=A_{1/2}/\sqrt{3}$, and also in the large-$Q^2$ region, where theory and data suggest that $A_{3/2}$ is suppressed relative to $A_{1/2}$. In the present work, we look for the source of the suppression of the $A_{1/2}$ amplitude at $Q^2=0$. The result is easy to understand in first approximation, when we look into the relation between the transverse amplitudes and the elementary form factors, defined by a gauge-invariant parametrization of the ${\gamma }^{\ast }N\to N(1520)$ transition current, near $Q^2=0$. There is a partial cancellation between contributions of two elementary form factors near $Q^2=0$. We conclude, however, that the correlation between the two elementary form factors at $Q^2=0$ is not sufficient to explain the transverse amplitude data below $Q^2=1$ GeV${}^2$. The description of the dependence of the transverse amplitudes on $Q^2$ requires the determination of the scale of variation of the elementary form factors in the range $Q^2=0$...0.5 GeV${}^2$,a region with almost non existent data. We conclude at the end that the low-$Q^2$ data for the transverse amplitudes can be well described when we relate the scale of variation of the elementary form factors with the nucleon dipole form factor.

    hep-phhep-exhep-latnucl-ex+1PRD(2024)·1 citation
12. 12*

    Description of Bhabha-scattering at small angles using the Monte Carlo generator ReneSANCe

    A. Arbuzov (1)🇷🇺 · S. Bondarenko (1)🇷🇺 · I. Boyko (1)🇷🇺 · Ya. Dydyshka (1,2)🇷🇺 · L. Kalinovskaya (1)🇷🇺 · A. Kampf (1)🇷🇺 · R. Sadykov (1)🇷🇺 · A. Tropina (1)🇷🇺 · V. Yermolchyk (1,2)🇷🇺 · Yu. Yermolchyk (1,2) ((1) Joint Institute for Nuclear Research, Dubna, 141980, (2) Research Institute for Nuclear Problems of Belarusian State University, Minsk, 220030)🇷🇺

    Results of a simulation of Bhabha small-angle scattering process at center-of-mass energy of 240~GeV and at the $Z$-boson resonance using the Monte Carlo generator {\tt{ReneSANCe}} are presented. For the given accuracy about $10^{-4}$ in estimating luminosity of future electron-positron accelerators, the minimum cutoff angle for simulated events is established.

    hep-phPhys.Part.Nucl.(2024)·0 citations
13. 13*

    What ultracold atoms tell us about the real-time dynamics of QCD in extreme conditions

    J. Berges🇩🇪

    I review developments of how compact table-top setups with ultracold atoms can help us to understand the more complex real-time dynamics of QCD probed in heavy-ion collision experiments.

    hep-phcond-mat.quant-gasEPJ Web Conf.(2024)·1 citation
14. 14*

    Thermal leptogenesis in anisotropic cosmology

    Mehran Dehpour🇮🇷

    There is no evidence that the universe must have been homogeneous and isotropic before the big bang nucleosynthesis. The Bianchi type-I cosmology is the simplest homogeneous but anisotropic cosmology. In this work, we investigate thermal leptogenesis, as a baryogenesis scenario, in the Bianchi type-I cosmology. Our results show that for specific values of the anisotropy, the modified thermal leptogenesis generated more baryon asymmetry than the standard one. In this way, anisotropy can help to achieve low-scale leptogenesis.

    hep-phastro-ph.COInt.J.Mod.Phys.A(2023)·6 citations
15. 15*

    Superconducting phases of strongly-interacting matter in large magnetic fields

    Geraint W. Evans🇬🇧

    The large magnetic fields of neutron stars and produced in heavy-ion collisions motivate investigation into the response of strongly-interacting matter to extreme magnetic forces beyond just theoretical interest. Furthermore, the varying temperature $T$, baryon chemical potential ${\mu }_B$, and aforementioned magnetic fields $B$, of these systems leads to questions concerning the phase structure of Quantum Chromodynamics (QCD) at large. At low temperatures, superconducting phases become a possible candidate for the ground state in the ${\mu }_B$-$B$ plane. This thesis investigates two scenarios where these phases emerge at $T=0$, with an emphasis on the type-II regime. Preceding the presentation of these works, the ${\mu }_B$-$B$ plane of the QCD phase diagram is reviewed such that the results can be placed in the wider context of this plane.

    hep-phhep-thnucl-th0 citations
16. 16*

    A discussion on the anomalous threshold enhancement of $J/\psi$ -- $\psi (3770)$ couplings and $X(6900)$ peak

    Ye Lu🇨🇳 · Chang Chen🇨🇳 · Guang-you Qin🇨🇳 · Han-Qing Zheng🇨🇳

    The attractive interaction between $J/\psi$ and $\psi (3770)$ has to be strong enough to form the molecular resonant structure, i.e., $X(6900)$. We argue that since $\psi (3770)$ decays predominantly into a $D\bar{D}$ pair, the interactions between $J/\psi$ and $\psi (3770)$ may be significantly enhanced due to the three point $D\bar{D}$ loop diagram. The enhancement comes from the anomalous threshold located at $t=-1.288$GeV${}^2$, which effect propagates into the $s$-channel partial wave amplitude in the vicinity of $\sqrt{s}\simeq 6.9$GeV. This effect may be helpful in forming the $X(6900)$ peak.

    hep-phhep-exCPC(2024)·6 citations
17. 17*

    High-$p_T$ Suppression in Small Systems

    Coleridge Faraday🇿🇦 · W. A. Horowitz🇿🇦

    We present first results for leading hadron suppression in small collision systems, from a convolved radiative and collisional pQCD energy loss model which receives a short path length correction to the radiative energy loss. We find that the short path length correction is exceptionally large for light flavor final states in both small and large collision systems, due to the disproportionate size of the correction for gluons. We examine various assumptions underlying the energy loss model through the calculation of energy loss weighted expectation values of ratios assumed small by the various assumptions. This calculation shows that the large formation time assumption, which is utilized by most contemporary energy loss models, is invalid for a large portion of the phenomenologically relevant parameter space.

    hep-phEPJ Web Conf.(2024)·0 citations
18. 18*

    Higher-order NLO radiative corrections to polarized muon decay spectrum

    A.B. Arbuzov🇷🇺 · U.E.Voznaya🇷🇺

    Higher-order QED radiative corrections to muon decay spectrum are evaluated within the QED structure function approach in the next-to-leading order logarithmic approximation. New analytical results are given in the $\mathcal{O}\left({\alpha }^3{\ln }^2(m_{\mu }^2/m_e^2)\right)$ order. Earlier results in $\mathcal{O}\left({\alpha }^2{\ln }^1(m_{\mu }^2/m_e^2)\right)$ and $\mathcal{O}\left({\alpha }^3{\ln }^3(m_{\mu }^2/m_e^2)\right)$ orders are partially corrected. Numerical estimates of different contributions are presented.

    hep-phPRD(2024)·5 citations
19. 19*

    Self-interacting Vectorial Dark Matter in a SM-like Dark Sector

    Van Que Tran🇨🇳 · Thong T. Q. Nguyen🇹🇼 · Tzu-Chiang Yuan🇹🇼

    A $SU(2{)}_D\times U(1{)}_D$ gauge-Higgs sector, an exact dark copy of the Standard Model (SM) one, is proposed. It is demonstrated that the dark gauge bosons ${\mathcal{W}}^{(p,m)}$, in analogous to the SM $W^{\pm }$, can fulfill the role as a self-interacting vector dark matter candidate, solving the core versus cusp and missing satellites problems faced by the conventional paradigm of collisionless weakly interacting massive particle. Constraints from collider, astroparticle and cosmology on such a self-interacting vector dark matter candidate are scrutinized. Implications for the future searches of ${\mathcal{W}}^{(p,m)}$ in direct detection experiments are discussed.

    hep-phastro-ph.COJCAP(2024)·18 citations
20. 20*

    Status of direct detection searches of heavy dark matter

    Marcin Kuźniak🇵🇱

    Dark matter accounts for 26% of the mass-energy density of the Universe, however, its nature and origins remain the most important open questions in physics. The search for Weakly Interacting Massive Particles (WIMPs), one of the leading dark matter particle candidates, is now in a decisive phase, with experiments targeting both the high-mass and the low-mass (1-10 GeV/$c^2$) WIMP scenarios. The status of the leading experimental searches is discussed, together with their prospects and challenges they are facing. Searches of heavy non-WIMP dark matter candidates are also briefly summarized.

    hep-phastro-ph.COastro-ph.IMhep-ex+1PoS(2023)·3 citations
21. 21*

    Hadronic decay of exotic mesons consisting of four charm quarks

    Hong-Fei Zhang🇨🇳 · Xue-Mei Mo🇨🇳 · Yu-Peng Yan🇹🇭

    In 2020, a di-$J/\psi$ resonance centered at around 6.9 $\mathrm{GeV}$ was discovered by the LHCb Collaboration, and was later confirmed by the ATLAS and CMS Collaborations. In addition to the 6.9-$\mathrm{GeV}$ resonance, its low energy counterpart centered at around 6552 $\mathrm{MeV}$ was also observed by the CMS Collaboration. In this paper, we calculate the inclusive decay width of such exotic mesons into light hadrons and into open charms, respectively, assuming them as either genuine tetraquarks or molecules composed of two $J/\psi$'s. Since the spins of these resonances have not yet been experimentally measured, regarding them as S-wave bound states, we consider all possible spin configurations, namely spin-0 and spin-2, that decay exclusively into double $J/\psi$, and find that the ratio ($\mathcal{R}$) of the decay width for the light-hadron final states to that for the charmed final states differs significantly among different spin configurations, which can help to explore the nature of the observed di-$J/\psi$ resonances and fix the mixing angle for the $J^{PC}=0^{++}$ tetraquark.

    hep-phPRD(2024)·12 citations
22. 22*

    Non-Abelian chiral soliton lattice in rotating QCD matter: Nambu-Goldstone and excited modes

    Minoru Eto🇯🇵 · Kentaro Nishimura🇯🇵 · Muneto Nitta🇯🇵

    The ground state of QCD with two flavors at a finite baryon chemical potential under rapid rotation is a chiral soliton lattice (CSL) of the $\eta$ meson, consisting of a stack of sine-Gordon solitons carrying a baryon number, due to the anomalous coupling of the $\eta$ meson to the rotation. In a large parameter region, the ground state becomes a non-Abelian CSL, in which due to the neutral pion condensation each $\eta$ soliton decays into a pair of non-Abelian sine-Gordon solitons carrying $S^2$ moduli originated from Nambu-Goldstone (NG) modes localized around it, corresponding to the spontaneously broken vector symmetry SU$(2{)}_{\mathrm{V}}$. There, the $S^2$ modes of neighboring solitons are anti-aligned, and these modes should propagate in the transverse direction of the lattice due to the interaction between the $S^2$ modes of neighboring solitons. In this paper, we calculate excitations including gapless NG modes and excited modes around non-Abelian and Abelian ($\eta$) CSLs, and find three gapless NG modes with linear dispersion relations (type-A NG modes): two isospinons ($S^2$ modes) and a phonon corresponding to the spontaneously broken vector SU$(2{)}_{\mathrm{V}}$ and translational symmetries around the non-Abelian CSL, respectively, and only a phonon for the Abelian CSL because of the recovering SU$(2{)}_{\mathrm{V}}$. We also find in the deconfined phase that the dispersion relation of the isospinons becomes of the Dirac type, {\it i.~e.~} linear even at large momentum.

    hep-phhep-thnucl-thJHEP(2024)·21 citations
23. 23*

    Charged lepton flavour violation in muons: theory overview

    Ana M. Teixeira🇫🇷

    We briefly overview some theoretical aspects of charged lepton flavour violation in rare muon transitions and decays. Relying on the effective field theory approach (model-independent), we discuss the probing power of charged lepton flavour violation processes regarding the new physics scale, especially in what concerns muon-electron conversion in nuclei. We then illustrate how these processes can provide valuable information (allowing to constrain, falsify - or conversely to learn about the underlying new physics properties) for a few examples of well-motivated extensions of the Standard Model. We finally comment on how leptonic CP violation should be carefully considered upon studies of charged lepton flavour violation in extensions of the Standard Model featuring heavy sterile fermions.

    hep-phPoS(2024)·0 citations
24. 24*

    Decays of Standard Model like Higgs boson $h\to \gamma \gamma ,Z\gamma$ in a minimal left-right symmetric model

    T.T. Hong🇻🇳 · V. K. Le🇻🇳 · L. T. T. Phuong🇻🇳 · N .C. Hoi🇻🇳 · N. T. K. Ngan🇻🇳 · N. H. T. Nha🇻🇳

    Two decay channels $h\to \gamma \gamma ,Z\gamma$ of the Standard Model-like Higgs in a left-right symmetry model are investigated under recent experimental data. We will show there exist one-loop contributions that affect the $h\to Z\gamma$ amplitude, but not the $h\to \gamma \gamma$ amplitude. From numerical investigations, we show that the signal strength ${\mu }_{Z\gamma }$ of the decay $h\to Z\gamma$ is still constrained strictly by that of $h\to \gamma \gamma$, namely $|\Delta {\mu }_{\gamma \gamma }|<38\%$ results in max $|\Delta {\mu }_{Z\gamma }|<46\%$. On the other hand, the future experimental sensitivity $|\Delta {\mu }_{\gamma \gamma }|=4\%$ still allows $|\Delta {\mu }_{Z\gamma }|$ reaches to values larger than the expected sensitivity $|\Delta {\mu }_{Z\gamma }|=23\%$.

    hep-phPTEP(2024)·8 citations
25. 25*

    Brodsky et al's defence does not work

    P. M. Stevenson🇺🇸

    In their defence of "maximum conformality" methods, Brodsky et al make the astonishing claim that any RG transformation a'=a(1+V_1 a + ...) in QCD must have V_1 proportional to b=(33-2n_f)/6. It is well known that this is not true. I emphasize again the correctness and central importance of the Celmaster-Gonsalves relation for the prescription dependence of the Lambda parameter.

    hep-phhep-exhep-th2 citations
26. 26*

    Testing Leptogenesis and Seesaw using Long-lived Particle Searches in the $B-L$ Model

    Wei Liu🇨🇳 · Frank F. Deppisch🇬🇧 · Zixiang Chen🇨🇳

    We discuss the potential of using long-lived particle (LLP) searches for right-handed neutrinos (RHNs) to test resonant leptogenesis and the seesaw mechanism. This is challenging if only RHNs are added to the Standard Model (SM), as naturally the active-sterile mixing strengths $|V_{\ell N}{|}^2$ are small, for 1 GeV $\lesssim M_N\lesssim 1000$ GeV. Instead, we consider the minimal $B-L$ gauge model, where a $Z^{\prime }$ gauge boson couples to fermions including the RHNs. During leptogenesis, this gauge coupling introduces scattering processes that washout the $B-L$ asymmetry. At colliders, it can lead to abundant production of RHNs which allows probing the associated seesaw mechanism using LLP searches. We find that LLP searches at the FCC-hh can test leptogenesis and the seesaw mechanism simultaneously, and probe the active-sterile mixing at or below the seesaw floor.

    hep-phPRD(2024)·9 citations
27. 27*

    Axion-Mediated Inelastic Dark Matter

    Kyu Jung Bae🇰🇷 · Jongkuk Kim🇰🇷

    We consider the axion-mediated scattering processes between dark matter (DM) and nucleus. Substantial contributions are made via the CP-odd gluonic current which induces the spin-dependent process. Since the QCD axion is too feebly coupled to the visible particles, non-QCD axions are necessary for the current DM experiments to accomplish the ample sensitivity. In the case of multi-component DM models, the inelastic scattering processes also make sizable contributions to the direct detection. The supersymmetry (SUSY) and clockwork (CW) mechanism provide a realistic model for the QCD and non-QCD axions and the axion-mediated DM scattering processes. In the SUSY CW axion model, the lightest axino is the DM particle and the axions mediate the elastic and inelastic scattering processes. We show that the current and future XENONnT can produce relevant constraints for some parameter space of the model.

    hep-ph3 citations
28. 28*

    Rare and exclusive few-body decays of the Higgs, Z, W bosons, and the top quark

    David d'Enterria🇨🇭 · Van Dung Le🇻🇳

    We perform an extensive survey of rare and exclusive few-body decays -- defined as those with branching fractions $\mathcal{B}\lesssim 10^{-5}$ into two to four final particles -- of the Higgs, Z, W bosons, and the top quark. Such rare decays can probe physics beyond the Standard Model (BSM), constitute a background for exotic decays into new BSM particles, and provide precise information on quantum chromodynamics factorization with small nonperturbative corrections. We tabulate the theoretical $\mathcal{B}$ values for about 200 rare decay channels of the four heaviest elementary particles, indicating the current experimental limits in their observation. Among those, we have computed for the first time ultrarare Higgs boson decays into photons and/or neutrinos, H and Z radiative decays into leptonium states, radiative H and Z quark-flavour-changing decays, and semiexclusive top-quark decays into a quark plus a meson, while updating predictions for a few other rare H, Z, and top quark partial widths. The feasibility of measuring each of these unobserved decays is estimated for p-p collisions at the high-luminosity Large Hadron Collider (HL-LHC), and for $e^{+}{e}^{-}$ and p-p collisions at the future circular collider (FCC).

    hep-phhep-exJ.Phys.G(2025)·41 citations
29. 29*

    Fully-heavy hadronic molecules $B_c^{(\ast )+}{B}_c^{(\ast )-}$ bound by fully-heavy mesons

    Wen-Ying Liu🇨🇳 · Hua-Xing Chen🇨🇳

    A lot of exotic hadrons were reported in the past twenty years, which bring us the renaissance of the hadron spectroscopy. Most of them can be understood as hadronic molecules, whose interactions are mainly due to the exchange of light mesons, and specifically, light vector mesons through the coupled-channel unitary approach within the local hidden-gauge formalism. It is still controversial whether the interaction arising from the exchange of heavy mesons is capable of forming hadronic molecules. We apply the coupled-channel unitary approach to study the fully-heavy $b\bar{b}c\bar{c}$ system, where the exchanged mesons can only be the fully-heavy vector mesons $J/\psi$, $B_c^{\ast }$, and ${\rm Y}$. Especially, the $J/\psi$ meson is much lighter than the $B_c^{(\ast )}$ mesons, so the present study can be taken as a general investigation on the question whether a lower-mass fully-heavy meson is able to bind two higher-mass fully-heavy hadrons. Our results suggest the existence of the fully-heavy hadronic molecules $|B_c^{+}{B}_c^{-};J^{PC}=0^{++}⟩$, $|B_c^{\ast +}{B}_c^{-}-c.c.;J^{PC}=1^{+-}⟩$, and $|B_c^{\ast +}{B}_c^{\ast -};J^{PC}=2^{++}⟩$ as well as the possible existence of $|B_c^{\ast +}{B}_c^{-}+c.c.;J^{PC}=1^{++}⟩$. These states are potentially to be observed in the ${\mu }^{+}{\mu }^{-}J/\psi$ and ${\mu }^{+}{\mu }^{-}{\rm Y}$ channels in future ATLAS, CMS, and LHCb experiments.

    hep-phhep-exhep-latEPJC(2025)·16 citations
30. 30*

    Limiting attractors in heavy-ion collisions

    Kirill Boguslavski🇦🇹 · Aleksi Kurkela🇳🇴 · Tuomas Lappi🇫🇮 · Florian Lindenbauer🇦🇹 · Jarkko Peuron🇫🇮

    We study universal features of the hydrodynamization process in heavy-ion collisions using QCD kinetic theory simulations for a wide range of couplings. We introduce the new concept of limiting attractors, which are obtained by extrapolation to vanishing and strong couplings. While the hydrodynamic limiting attractor emerges at strong couplings and is governed by the viscosity-related relaxation time scale ${\tau }_R$, we identify a bottom-up limiting attractor at weak couplings. It corresponds to the late stages of the perturbative bottom-up thermalization scenario and exhibits isotropization on the time scale ${\tau }_{\text{BMSS}}={\alpha }_s^{-13/5}/Q_s$. In contrast to hydrodynamic limiting attractors, at finite couplings the bottom-up limiting attractor provides a good universal description of the pre-hydrodynamic evolution of jet and heavy-quark momentum broadening ratios ${\hat{q}}^{yy}/{\hat{q}}^{zz}$ and ${\kappa }_T/{\kappa }_z$. We also provide parametrizations for these ratios for phenomenological studies of pre-equilibrium effects on jets and heavy quarks.

    hep-phnucl-thPLB(2024)·29 citations
31. 31*

    Full three-loop Renormalisation of an abelian chiral Gauge Theory with non-anticommuting ${\gamma }_5$ in the BMHV Scheme

    Dominik Stöckinger🇩🇪 · Matthias Weißwange🇩🇪

    In this work we present a complete three-loop renormalisation of an abelian chiral gauge theory within the Breitenlohner-Maison/'t Hooft-Veltman (BMHV) scheme of dimensional regularisation (DReg). In this scheme the ${\gamma }_5$-matrix appearing in gauge interactions is a non-anticommuting object, leading to a breaking of gauge and BRST invariance. Employing an efficient method based on the quantum action principle, we obtain the complete three-loop counterterm action which serves both to render the theory finite and to restore gauge and BRST invariance. The UV singular counterterms involve not only higher order $ϵ$-poles but also new counterterm structures emerging at the three-loop level for the first time; the finite symmetry-restoring counterterms are restricted to the same structures as at lower loop orders, just with different coefficients, aligning with our expectations. Both the singular and the finite counterterms include structures which cannot be obtained by the standard multiplicative renormalisation. Our results demonstrate that a rigorous treatment of chiral gauge theories with ${\gamma }_5$ defined in the BMHV scheme at the multi-loop level is possible and that the obtained counterterm action is suitable for computer implementations, allowing automated calculations without ambiguities caused by ${\gamma }_5$.

    hep-phJHEP(2024)·21 citations
32. 32*

    A New Solution to the Strong CP Problem

    S.A. Larin🇷🇺

    We suggest a new solution to the strong CP problem. The solution is based on the proper use of the boundary conditions for the QCD generating functional integral. We expand the perturbative boundary conditions to both perturbative and nonperturbative fields integrated in the QCD generating functional integral. It allows to nullify the CP odd term in the QCD Lagrangian and thus to solve the strong CP problem. The presently popular solution to the strong CP problem with introducing axions violates the principle of renormalizability of Quantum Field Theory, which is very successful phenomenologically. Our solution obeys the principle of renormalizability of Quantum Field Theory and does not involve new exotic particles like axions.

    hep-phSymmetry(2023)·2 citations
33. 33*

    New Constraint for Isotropic Lorentz Violation from LHC Data

    David Amram🇫🇷 · Killian Bouzoud🇫🇷 · Nicolas Chanon🇫🇷 · Hubert Hansen🇫🇷 · Marcos R. Ribeiro Jr.🇧🇷 · Marco Schreck🇧🇷

    New calculations for the kinematics of photon decay to fermions in vacuo under an isotropic violation of Lorentz invariance (LV), parameterized by the Standard-Model Extension (SME), are presented in this paper and used to interpret prompt photon production in LHC data. The measurement of inclusive prompt photon production at the LHC Run 2, with photons observed up to a transverse energy of 2.5 TeV, provides the lower bound ${\tilde{\kappa }}_{\mathrm{tr}}>-1.06\times 10^{-13}$ on the isotropic coefficient ${\tilde{\kappa }}_{\mathrm{tr}}$ at 95% confidence level. This result improves over the previous bound from hadron colliders by a factor of 55. The calculations for the kinematics of photon decay have further potential use to constrain LV coefficients from the appearance of fermion pairs, for instance, top-antitop.

    hep-phPRL(2024)·8 citations
34. 34*

    Incoherent $\mathrm{J}/\psi$ production at large $|t|$ identifies the onset of saturation at the LHC

    Jan Cepila🇨🇿 · Jesus Guillermo Contreras🇨🇿 · Marek Matas🇨🇿 · Alexandra Ridzikova🇨🇿

    We predict that the onset of gluon saturation can be uniquely identified using incoherent $\mathrm{J}/\psi$ production in Pb$–$Pb collisions at currently accessible energies of the LHC. The diffractive incoherent photo-production of a $\mathrm{J}/\psi$ vector meson off a hadron provides information on the partonic structure of the hadron. Within the Good-Walker approach it specifically measures the variance over possible target configurations of the hadronic colour field. For this process then, gluon saturation sets in when the cross section reaches a maximum, as a function of the centre-of-mass energy of the photon-hadron system ($W$), and then decreases. We benchmark the energy-dependent hot-spot model against data from HERA and the LHC and demonstrate a good description of the available data. We show that the study of the energy dependence of the incoherent production of $\mathrm{J}/\psi$ allows us to pinpoint the onset of saturation effects by selecting the region of Mandelstam-$t$ around 1 GeV${}^2$ where the contribution of hot spots is dominant. We predict the onset of saturation in a Pb target to occur for $W$ around a few hundred GeV. This can be measured with current data in ultra-peripheral Pb$–$Pb collisions at the LHC.

    hep-phhep-exPLB(2024)·18 citations
35. 35*

    Renormalisation group running effects in $pp\to t\bar{t}h$ in the Standard Model Effective Field Theory

    Stefano Di Noi🇮🇹 · Ramona Gröber🇮🇹

    We study the effects of renormalisation group running of the Wilson coefficients in Standard Model Effective Field Theory, using the process $pp\to t\bar{t}h$ as a showcase. We consider both strong and top Yukawa running effects, since the latter can be relevant in presence of large Wilson coefficients. We study the difference between the use of a dynamical and fixed renormalisation scale by exploring different scenarios for the higher-dimensional operators at the high energy scale of new physics, assumed to be at the TeV scale.

    hep-phEPJC(2024)·28 citations
36. 36*

    Simultaneous minijets and QGP evolution

    Charles Gale🇨🇦 · Sangyong Jeon🇨🇦 · Daniel Pablos🇮🇹 · Mayank Singh🇺🇸

    Minijets traversing through the QGP formed in heavy-ion collisions deposit significant amount of energy in the bulk medium. They also create gradients in temperatures which alter the flow profile and enhance entropy production. We study the effects of minijets in a simultaneous hydro + jet framework and find that inclusion of minijets requires recalibration of transport properties extracted from the model-to-data comparisons.

    hep-phnucl-thEPJ Web Conf.(2024)·0 citations
37. 37*

    Quarkonium production in high energy $pp$ collisions

    Jiaxing Zhao🇫🇷 · Pol Bernard Gossiaux🇫🇷 · Taesoo Song🇩🇪 · Elena Bratkovskaya🇩🇪 · Joerg Aichelin🇫🇷

    We investigate the charmonium and bottomonium production in $pp$ collisions using the Wigner densities formalism. The Wigner density of the quarkonia is approximated by analytical 3-D isotropic harmonic oscillator Wigner densities with the same root-mean-square radius given by the solution of the Schrödinger equation. This approach reproduces quite well the available experimental transverse momentum and rapidity distributions.

    hep-phEPJ Web Conf.(2024)·6 citations
38. 38*

    Opening windows with Isospin-Violating Dark Matter

    Jason Kumar🇺🇸 · Danny Marfatia🇺🇸 · Ningqiang Song🇨🇳

    We consider the effect of isospin-violating dark matter-nucleon interactions on direct detection constraints in the regime of small dark matter mass and large scattering cross section. Isospin-violation can lead to both reductions in sensitivity (due to a reduced cross section for scattering with nuclei in the detector) and enhancements in sensitivity (due to a reduced cross section for scattering in the overburden). Isospin-violating effects can thus open up some closed regions of parameter space, while closing off other regions.

    hep-phastro-ph.COhep-exPLB(2024)·1 citation
39. 39*

    Soft-photon spectra and the LBK theorem

    Roger Balsach🇩🇪 · Domenico Bonocore🇩🇪 · Anna Kulesza🇩🇪

    The study of next-to-leading-power (NLP) corrections in soft emissions continues to attract interest both in QCD and in QED. Soft-photon spectra in particular provide a clean case-study for the experimental verification of the Low-Burnett-Kroll (LBK) theorem. In this paper we study the consistency of the LBK theorem in the context of an ambiguity arising from momentum-conservation constraints in the computation of non-radiative amplitudes. We clarify that this ambiguity leads to various possible formulations of the LBK theorem, which are all equivalent up to power-suppressed effects (i.e. beyond the formal accuracy of the LBK theorem). We also propose a new formulation of the LBK theorem with a modified shifted kinematics which facilitates the numerical computation of non-radiative amplitudes with publicly available tools. Furthermore, we present numerical results for soft-photon spectra in the associated production of a muon pair with a photon, both in $e^{+}{e}^{-}$ annihilation and proton-proton collisions.

    hep-phPRD(2024)·11 citations
40. 40*

    $(g-2{)}_{e,\mu }$ anomalies and decays $h\to e_a{e}_b$, $Z\to e_a{e}_b$, and $e_b\to e_a\gamma$ in a two Higgs doublet model with inverse seesaw neutrinos

    T. T. Hong🇻🇳 · Q.Duyet Tran🇻🇳 · T. Phong Nguyen🇻🇳 · L.T. Hue🇻🇳 · N.H.T. Nha🇻🇳

    The lepton flavor violating decays $h\to e_b^{\pm }{e}_a^{\mp }$, $Z\to e_b^{\pm }{e}_a^{\mp }$, and $e_b\to e_a\gamma$ will be discussed in the framework of the Two Higgs doublet model with presence of new inverse seesaw neutrinos and a singly charged Higgs boson that accommodate both $1\sigma$ experimental data of $(g-2)$ anomalies of the muon and electron. Numerical results indicate that there exist regions of the parameter space supporting all experimental data of $(g-2{)}_{e,\mu }$ as well as the promising LFV signals corresponding to the future experimental sensitivities.

    hep-phEPJC(2024)·7 citations
41. 41*

    Enhanced contribution of the pairing gap to the QCD equation of state at large isospin chemical potential

    Yuki Fujimoto🇺🇸

    I study QCD at large isospin density, which is known to be in the superfluid state with Cooper pairs carrying the same quantum number as pions. I solve the gap equation derived from the perturbation theory up to the next-to-leading order corrections. The pairing gap at large isospin chemical potential is found to be enhanced compared to the color-superconducting gap at large baryon chemical potential due to the $\sqrt{2}$ difference in the exponent arising from the stronger attraction in one-gluon exchange in the singlet channel. Then, using the gap function, I evaluate the contribution of the condensation energy of the superfluid state to the QCD equation of state. At isospin chemical potential of a few GeV, where the lattice QCD and the perturbative QCD can be both applied, the effect of the condensation energy becomes dominant even compared to the next-to-leading order corrections to the pressure in the perturbation theory. It resolves the discrepancy between the recent lattice QCD results and the perturbative QCD result.

    hep-phhep-latnucl-thPRD(2024)·25 citations
42. 42*

    Exploring the Impact of anti-shadowing effect on Unintegrated Gluon Distributions in the MD-BFKL Equation

    Xiaopeng Wang🇨🇳 · Yanbing Cai🇨🇳 · Xurong Chen🇨🇳

    This paper presents a comprehensive analysis of the MD-BFKL equation, considering both shadowing and anti-shadowing effects in gluon recombination processes. By deriving analytical expressions for unintegrated gluon distributions through the solution of the MD-BFKL equation, with and without the incorporation of anti-shadowing effect, we offer new insights into the influence of these effects on the behavior of unintegrated gluon distributions. Our results, when compared to the CT18NLO gluon distribution function, demonstrate that the anti-shadowing effect has a notably stronger impact on the characteristics of unintegrated gluon distributions, particularly in regions of high rapidity and momentum. This work significantly contributes to the understanding of gluon recombination mechanisms and their implications in high energy physics.

    hep-phCPC(2024)·1 citation
43. 43*

    Physical Signatures of Fermion-Coupled Axion Dark Matter

    Asher Berlin🇺🇸 · Alexander J. Millar🇺🇸 · Tanner Trickle🇺🇸 · Kevin Zhou🇺🇸

    In the presence of axion dark matter, fermion spins experience an "axion wind" torque and an "axioelectric" force. We investigate new experimental probes of these effects and find that magnetized analogs of multilayer dielectric haloscopes can explore orders of magnitude of new parameter space for the axion-electron coupling. We also revisit the calculation of axion absorption into in-medium excitations, showing that axioelectric absorption is screened in spin-polarized targets, and axion wind absorption can be characterized in terms of a magnetic energy loss function. Finally, our detailed theoretical treatment allows us to critically examine recent claims in the literature. We find that axioelectric corrections to electronic energy levels are smaller than previously estimated and that the purported electron electric dipole moment due to a constant axion field is entirely spurious.

    hep-phastro-ph.COcond-mat.mtrl-scihep-exJHEP(2024)·34 citations
44. 44*

    Exponentiation of soft quark effects from the replica trick

    Melissa van Beekveld🇬🇧 · Leonardo Vernazza🇮🇹 · Chris D. White🇬🇧

    In this paper, we show that multiple maximally soft (anti-)quark and gluon emissions exponentiate at the level of either the amplitude or cross-section. We first show that such emissions can be captured by introducing new soft emission operators, which serve to generalise the well-known Wilson lines describing emissions of maximally soft gluons. Next, we prove that vacuum expectation values of these operators exponentiate using the replica trick, a statistical-physics argument that has previously been used to demonstrate soft-gluon exponentiation properties in QCD. The obtained results are general, i.e. not tied to a particular scattering process. We illustrate our arguments by demonstrating the exponentiation of certain real and virtual corrections affecting subleading partonic channels in deep-inelastic scattering.

    hep-phJHEP(2024)·7 citations
45. 45*

    Inhomogeneous Energy Injection in the 21-cm Power Spectrum: Sensitivity to Dark Matter Decay

    Yitian Sun🇺🇸 · Joshua W. Foster🇺🇸 · Hongwan Liu🇺🇸 · Julian B. Muñoz🇺🇸 · Tracy R. Slatyer🇺🇸

    The 21-cm signal provides a novel avenue to measure the thermal state of the universe during cosmic dawn and reionization (redshifts $z\sim 5-30$), and thus to probe energy injection from decaying or annihilating dark matter (DM). These DM processes are inherently inhomogeneous: both decay and annihilation are density dependent, and furthermore the fraction of injected energy that is deposited at each point depends on the gas ionization and density, leading to further anisotropies in absorption and propagation. In this work, we develop a new framework for modeling the impact of spatially inhomogeneous energy injection and deposition during cosmic dawn, accounting for ionization and baryon density dependence, as well as the attenuation of propagating photons. We showcase how this first completely inhomogeneous treatment affects the predicted 21-cm power spectrum in the presence of exotic sources of energy injection, and forecast the constraints that upcoming HERA measurements of the 21-cm power spectrum will set on DM decays to photons and to electron/positron pairs. These projected constraints considerably surpass those derived from CMB and Lyman-$\alpha$ measurements, and for decays to electron/positron pairs they exceed all existing constraints in the sub-GeV mass range, reaching lifetimes of $\sim 10^{28}\mathrm{s}$. Our analysis demonstrates the unprecedented sensitivity of 21-cm cosmology to exotic sources of energy injection during the cosmic dark ages. Our code, $DM21cm$, includes all these effects and is publicly available in an accompanying release.

    hep-phastro-ph.COastro-ph.HEPRD(2025)·55 citations
46. 46*

    Anomaly detection with flow-based fast calorimeter simulators

    Claudius Krause🇦🇹 · Benjamin Nachman🇺🇸 · Ian Pang🇺🇸 · David Shih🇺🇸 · Yunhao Zhu🇺🇸

    Recently, several normalizing flow-based deep generative models have been proposed to accelerate the simulation of calorimeter showers. Using CaloFlow as an example, we show that these models can simultaneously perform unsupervised anomaly detection with no additional training cost. As a demonstration, we consider electromagnetic showers initiated by one (background) or multiple (signal) photons. The CaloFlow model is designed to generate single photon showers, but it also provides access to the shower likelihood. We use this likelihood as an anomaly score and study the showers tagged as being unlikely. As expected, the tagger struggles when the signal photons are nearly collinear, but is otherwise effective. This approach is complementary to a supervised classifier trained on only specific signal models using the same low-level calorimeter inputs. While the supervised classifier is also highly effective at unseen signal models, the unsupervised method is more sensitive in certain regions and thus we expect that the ultimate performance will require a combination of these approaches.

    hep-phastro-ph.IMhep-exphysics.data-an+1PRD(2024)·15 citations
47. 47*

    The Constructive Method for Massive Particles in QED

    Hsing-Yi Lai🇺🇸 · Da Liu🇺🇸 · John Terning🇺🇸

    The constructive method of determining amplitudes from on-shell pole structure has been shown to be promising for calculating amplitudes in a more efficient way. However, challenges have been encountered when a massless internal photon is involved in the gluing of three-point amplitudes with massive external particles. In this paper, we use the original on-shell method, old-fashioned perturbation theory, to shed light on the constructive method, and show that one can derive the Feynman amplitude by correctly identifying the residue even when there is an internal photon involved.

    hep-phhep-thJHEP(2024)·12 citations
48. 48*

    On heavy-flavour jets with Soft Drop

    Simone Caletti🇨🇭 · Andrea Ghira🇮🇹 · Simone Marzani🇮🇹

    We study hadronic jets that are tagged as heavy-flavoured, i.e. they contain either beauty or charm. In particular, we consider heavy-flavour jets that have been groomed with the Soft Drop algorithm. In order to achieve a deeper understanding of these objects, we apply resummed perturbation theory to jets initiated by a massive quark and we perform analytic calculations for two variables that characterise Soft Drop jets, namely the opening angle and the momentum fraction of the splitting that passes Soft Drop. We compare our findings to Monte Carlo simulations. Furthermore, we investigate the correlation between the Soft Drop energy fraction and alternative observables that aim to probe heavy-quark fragmentation functions.

    hep-phEPJC(2024)·25 citations
49. 49*

    The NNLO soft function for N-jettiness in hadronic collisions

    Guido Bell🇩🇪 · Bahman Dehnadi🇩🇪 · Tobias Mohrmann🇩🇪 · Rudi Rahn🇬🇧

    We compute the N-jettiness soft function in hadronic collisions to next-to-next-to-leading order (NNLO) in the strong-coupling expansion. Our calculation is based on an extension of the SoftSERVE framework to soft functions that involve an arbitrary number of lightlike Wilson lines. We present numerical results for 1-jettiness and 2-jettiness, and illustrate that our formalism carries over to a generic number of jets by calculating a few benchmark points for 3-jettiness. We also perform a detailed analytic study of the asymptotic behaviour of the soft-function coefficients at the edges of phase space, when one of the jets becomes collinear to another jet or beam direction, and comment on previous calculations of the N-jettiness soft function.

    hep-phJHEP(2024)·22 citations
50. 50*

    Residual ANODE

    Ranit Das🇺🇸 · Gregor Kasieczka🇩🇪 · David Shih🇺🇸

    We present R-ANODE, a new method for data-driven, model-agnostic resonant anomaly detection that raises the bar for both performance and interpretability. The key to R-ANODE is to enhance the inductive bias of the anomaly detection task by fitting a normalizing flow directly to the small and unknown signal component, while holding fixed a background model (also a normalizing flow) learned from sidebands. In doing so, R-ANODE is able to outperform all classifier-based, weakly-supervised approaches, as well as the previous ANODE method which fit a density estimator to all of the data in the signal region instead of just the signal. We show that the method works equally well whether the unknown signal fraction is learned or fixed, and is even robust to signal fraction misspecification. Finally, with the learned signal model we can sample and gain qualitative insights into the underlying anomaly, which greatly enhances the interpretability of resonant anomaly detection and offers the possibility of simultaneously discovering and characterizing the new physics that could be hiding in the data.

    hep-phcs.LGhep-exphysics.data-an24 citations
51. 51*

    Can we measure Double DVCS at JLab and the EIC?

    K. Deja🇵🇱 · V. Martinez-Fernandez🇵🇱 · B. Pire🇫🇷 · P. Sznajder🇵🇱 · J. Wagner🇵🇱

    Double deeply virtual Compton scattering (DDVCS) is a very precise tool for the nucleon tomography. Its measurement requires high luminosity electron beams and precise dedicated detectors, since its amplitude is quite small in the interesting kinematical domain where collinear QCD factorization allows the extraction of quark and gluon generalized parton distributions (GPDs). We analyze the prospects for its study in the JLab energy domain as well as in higher energy electron-ion colliders. Our results are very encouraging for various observables both with an unpolarized and polarized lepton beam. Using various realistic models for GPDs, we demonstrate that DDVCS measurements are indeed very sensitive to their behaviour. Implementing our lowest order cross-section formulae in the EpIC Monte Carlo generator, we estimate the expected number of interesting events.

    hep-phhep-exnucl-thPoS(2024)·3 citations
52. 52*

    Thermal dilepton production in heavy-ion collisions at beam-energy-scan (BES) energies

    Jessica Churchill🇨🇦 · Lipei Du🇨🇦 · Bailey Forster🇨🇦 · Han Gao🇨🇦 · Greg Jackson🇫🇷 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦

    The lepton pair production rate at finite temperature and at next-to-leading-order (NLO) is calculated for quark-gluon plasma at non-zero baryon density. Yields are obtained using a (3+1)D multicomponent simulation capable of reproducing hadronic observables measured in the RHIC Beam Energy Scan. Spectra of intermediate invariant mass dileptons are compared with measurements from the STAR collaboration. The result of a study where the temperature information obtained from the dilepton spectrum from heavy-ion collisions performed at different energies and centralities is presented.

    ↳ nucl-thhep-phEPJ Web Conf.(2024)·4 citations
53. 53*

    Some simple theories of gravity with propagating torsion

    Yusuke Mikura🇯🇵 · Vincenzo Naso🇮🇹 · Roberto Percacci🇮🇹

    We consider antisymmetric Metric-Affine Theories of Gravity with a Lagrangian containing the most general terms up to dimension four and search for theories that are ghost- and tachyon-free when expanded around flat space. We find new examples that propagate only the graviton and one other massive degree of freedom of spin zero, one or two. These models require terms of the form $(\nabla T{)}^2$ in the Lagrangian, that have been largely ignored in the literature.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2024)·25 citations
54. 54*

    Why are hydrodynamic theories applicable beyond the hydrodynamic regime?

    Sunil Jaiswal🇺🇸 · Jean-Paul Blaizot🇫🇷 · Rajeev S. Bhalerao🇮🇳 · Zenan Chen🇨🇳 · Amaresh Jaiswal🇮🇳 · Li Yan🇨🇳

    We present an alternative approach to deriving second-order non-conformal hydrodynamics from the relativistic Boltzmann equation. We demonstrate how constitutive relations for shear and bulk stresses can be transformed into dynamical evolution equations, resulting in Israel-Stewart-like (ISL) hydrodynamics. To understand the far-from-equilibrium applicability of such ISL theories, we investigate the one-dimensional boost-invariant Boltzmann equation using special moments of the distribution function for a system with finite particle mass. Our analysis reveals that the mathematical structure of the ISL equations is akin to that of moment equations, enabling them to approximately replicate even the collisionless dynamics. We conclude that this particular feature is important in extending the applicability of ISL theories beyond the hydrodynamic regime.

    ↳ nucl-thhep-phEPJ Web Conf.(2024)·1 citation
55. 55*

    Baryogenesis in $R^2$-Higgs Inflation: the Gravitational Connection

    Yann Cado🇫🇷 · Christoph Englert🇬🇧 · Tanmoy Modak🇩🇪 · Mariano Quirós🇪🇸

    $R^2$-Higgs inflation stands out as one of the best-fit models of Planck data. Using a covariant formalism for the inflationary dynamics and the production of helical gauge fields, we show that the observed baryon asymmetry of the Universe (BAU) can be obtained when this model is supplemented by a dimension-six CP-violating term $\sim (R/{\Lambda }^2)B_{\mu \nu }{\tilde{B}}^{\mu \nu }$ in the hypercharge sector. At linear order, values of $\Lambda \simeq 2.5\times 10^{-5}{M}_{\mathrm{P}}$ produce, in the $R^2$-like regime, sufficient helical hypermagnetic fields to create the observed matter-antimatter asymmetry during the electroweak crossover. However, the Schwinger effect of fermion pair production can play a critical role in this context, and that scale is significantly lowered when the backreaction of the fermion fields on the gauge field production is included. In all cases, the helical field configurations can remain robust against washout after the end of inflation.

    ↳ astro-ph.COgr-qchep-phPRD(2024)·7 citations
56. 56*

    From linear to nonlinear Breit-Wheeler pair production in laser-solid interactions

    Huai-Hang Song🇨🇳 · Wei-Min Wang🇨🇳 · Min Chen🇨🇳 · Zheng-Ming Sheng🇨🇳

    During the ultraintense laser interaction with solids (overdense plasmas), the competition between two possible quantum electrodynamics (QED) mechanisms responsible for $e^{\pm }$ pair production, i.e., linear and nonlinear Breit-Wheeler (BW) processes, remains to be studied. Here, we have implemented the linear BW process via a Monte Carlo algorithm into the QED particle-in-cell (PIC) code YUNIC, enabling us to self-consistently investigate both pair production mechanisms in the plasma environment. By a series of 2D QED-PIC simulations, the transition from the linear to the nonlinear BW process is observed with the increase of laser intensities in the typical configuration of a linearly polarized laser interaction with solid targets. A critical normalized laser amplitude about $a_0\sim$ 400-500 is found under a large range of preplasma scale lengths, below which the linear BW process dominates over the nonlinear BW process. This work provides a practicable technique to model linear QED processes via integrated QED-PIC simulations. Moreover, it calls for more attention to be paid to linear BW pair production in near future 10-PW-class laser-solid interactions.

    ↳ physics.plasm-phhep-phPRE(2024)·5 citations
57. 57*

    Modeling the core-halo mass relation in fuzzy dark matter halos

    Hiroki Kawai · Ayuki Kamada🇵🇱 · Kohei Kamada🇯🇵 · Naoki Yoshida🇯🇵

    Fuzzy dark matter (FDM) is an intriguing candidate alternative to the standard cold dark matter (CDM). The FDM model predicts that dark halos have characteristic core structures generated by the effect of quantum pressure, which is different from the structure of CDM halos. We devise a semi-analytic model of a FDM halo density profile by assuming that the density distribution results from the redistribution of mass in a halo with the Navarro-Frenk-White profile. We calculate the mass redistribution radius by considering dynamical relaxation within the FDM halo. We adopt a concentration-halo mass relation with lower concentration compared to that in the CDM model below the half mode mass, which originates from the suppressed matter density fluctuations at small length scales. Our model reproduces the core-halo mass relation (CHMR) found in the numerical simulation of \citet{2014NatPh..10..496S} at $z<1$. We show that the CHMR is well described by a double power law, unlike previous studies that approximate it by a single power law. Our model predictions are in reasonable agreement with the results of the largest FDM simulation of \citet{2021MNRAS.506.2603M} at $z=3$. We find that the core mass for a given halo mass follows the log-normal distribution, both in our model and in the simulation results for the first time, and quantitatively compare the variance of the distribution among them. Although our model does not fully explain the scatter of the CHMR, we show the scatter of the concentration-halo mass relation sizably contributes to them.

    ↳ astro-ph.COhep-phPRD(2024)·10 citations
58. 58*

    Nearest neighbour analysis as a new probe for fuzzy dark matter

    Hamed Manouchehri Kousha🇮🇷 · Mohammad Ansarifard🇮🇷 · Aliakbar Abolhasani🇮🇷

    Fuzzy dark matter (FDM) is a promising candidate for dark matter, characterized by its ultra-light mass, which gives rise to wave effects at astrophysical scales. These effects offer potential solutions to the small-scale issues encountered within the standard cold dark matter (CDM) paradigm. In this paper, we investigate the large-scale structure of the cosmic web using FDM simulations, comparing them to CDM-only simulations and a simulation incorporating baryonic effects. Our study employs the nearest neighbor (NN) analysis as a new statistical tool for examining the structure and statistics of the cosmic web in an FDM universe. This analysis could capture the information absent in the two-point correlation functions. In particular, we analyze data related to the spherical contact, nearest neighbor distances, and the angle between the first and second nearest neighbors of halos. Specifically, we utilize probability distribution functions, statistical moments, and fitting parameters, as well as G(x), F(x), and J(x) functions to analyze the above data. Remarkably, the results from the FDM simulations differ significantly from the others across these analyses, while no noticeable distinction is observed between the baryonic and CDM-only simulations. Moreover, the lower FDM mass leads to more significant deviations from the CDM simulations. These compelling results highlight the efficiency of the NN analysis - mainly through the use of the J(x) function, $s_3$, $l_3$ and $a_4$ parameters - as a prominent new tool for investigating FDM on large scales and making observational predictions.

    ↳ astro-ph.COhep-phMNRAS(2024)·4 citations
59. 59*

    Systematic Improvement of $x$-dependent Unpolarized Nucleon Generalized Parton Distribution in Lattice-QCD Calculation

    Jack Holligan🇺🇸 · Huey-Wen Lin🇺🇸

    We present a first study of the effects of renormalization-group resummation (RGR) and leading-renormalon resummation (LRR) on the systematic errors of the unpolarized isovector nucleon generalized parton distribution in the framework of large-momentum effective theory (LaMET). This work is done using lattice gauge ensembles generated by the MILC collaboration, consisting of 2+1+1 flavors of highly improved staggered quarks with a physical pion mass at lattice spacing $a\approx 0.09$ fm and a box width $L\approx 5.76$ fm. We present results for the nucleon $H$ and $E$ GPDs with average boost momentum $P_z\approx 2$ GeV at momentum transfers $Q^2=[0,0.97]$ GeV${}^2$ at skewness $\xi =0$ as well as $Q^2\in 0.23$ GeV${}^2$ at $\xi =0.1$, renormalized in the $\overline{\mathrm{MS}}$ scheme at scale $\mu =2.0$ GeV, with two- and one-loop matching, respectively. We demonstrate that the simultaneous application of RGR and LRR significantly reduces the systematic errors in renormalized matrix elements and distributions for both the zero and nonzero skewness GPDs, and that it is necessary to include both RGR and LRR at higher orders in the matching and renormalization processes.

    ↳ hep-lathep-phnucl-thPRD(2024)·29 citations
60. 60*

    Acausality in truncated 'MIS'-type theory

    Sukanya Mitra🇮🇳

    The causal-stable Muller-Israel-Stewart (MIS) theory is known to have a finite number of out of equilibrium derivative order corrections but requires treating the viscosity tensor as a separate degree of freedom with its own equations of motion, apart from the fundamental fluid degrees of freedom like velocity and temperature. In this work, I will show that it is possible to rewrite the MIS theory only in terms of velocity and temperature, but the resultant constitutive relation for dissipation must include all orders of gradient corrections. In this work I will argue that an all-order resummation of gradient contributions is equivalent to introducing new `non-fluid' degrees of freedom in the MIS theory. It will also be shown, using the relativistic quantum causality condition, that any finitely truncated order of derivative correction, however high it is, leads to a theory that is acausal, unless the corrections are infinitely summed up to all orders.

    ↳ gr-qchep-phhep-thnucl-thPRD(2024)·10 citations
61. 61*

    Experimental search for invisible dark matter axions around 22 {\mu}eV

    Younggeun Kim🇰🇷 · Junu Jeong🇰🇷 · SungWoo Youn🇰🇷 · Sungjae Bae🇰🇷 · Kiwoong Lee🇰🇷 · Arjan F. van Loo🇯🇵 · Yasunobu Nakamura🇯🇵 · Seonjeong Oh🇰🇷 · Taehyeon Seong🇰🇷 · Sergey Uchaikin🇰🇷 · Jihn E. Kim🇰🇷 · Yannis K. Semertzidis🇰🇷

    The axion has emerged as the most attractive solution to two fundamental questions in modern physics related to the charge-parity invariance in strong interactions and the invisible matter component of our universe. Over the past decade, there have been many theoretical efforts to constrain the axion mass based on various cosmological assumptions. Interestingly, different approaches from independent groups produce good overlap between 20 and 30 {\mu}eV. We performed an experimental search to probe the presence of dark matter axions within this particular mass region. The experiment utilized a multi-cell cavity haloscope embedded in a 12 T magnetic field to seek for microwave signals induced by the axion-photon coupling. The results ruled out the KSVZ axions as dark matter over a mass range between 21.86 and 22.00 {\mu}eV at a 90% confidence level. This represents a sensitive experimental search guided by specific theoretical predictions

    ↳ hep-exhep-phPRL(2024)·55 citations
62. 62*

    A double take on early and interacting dark energy from JWST

    Matteo Forconi🇮🇹 · William Giarè🇬🇧 · Olga Mena🇪🇸 · Ruchika🇮🇹 · Eleonora Di Valentino🇬🇧 · Alessandro Melchiorri🇮🇹 · Rafael C. Nunes🇧🇷

    The very first light captured by the James Webb Space Telescope (JWST) revealed a population of galaxies at very high redshifts more massive than expected in the canonical $\Lambda$CDM model of structure formation. Barring, among others, a systematic origin of the issue, in this paper, we test alternative cosmological perturbation histories. We argue that models with a larger matter component ${\Omega }_m$ and/or a larger scalar spectral index $n_s$ can substantially improve the fit to JWST measurements. In this regard, phenomenological extensions related to the dark energy sector of the theory are appealing alternatives, with Early Dark Energy emerging as an excellent candidate to explain (at least in part) the unexpected JWST preference for larger stellar mass densities. Conversely, Interacting Dark Energy models, despite producing higher values of matter clustering parameters such as ${\sigma }_8$, are generally disfavored by JWST measurements. This is due to the energy-momentum flow from the dark matter to the dark energy sector, implying a smaller matter energy density. Upcoming observations may either strengthen the evidence or falsify some of these appealing phenomenological alternatives to the simplest $\Lambda$CDM picture.

    ↳ astro-ph.COhep-phJCAP(2024)·76 citations
63. 63*

    Cosmic Recombination in the Presence of Primordial Magnetic Fields

    Karsten Jedamzik (U. Montpellier 2, LUPM)🇫🇷 · Tom Abel (KIPAC, Menlo Park and SLAC and Stanford U., Physics Departement)🇺🇸 · Yacine Ali-Haimoud (New York University)🇺🇸

    Primordial magnetic fields (PMFs) may explain observations of magnetic fields on extragalactic scales. They are most cleanly constrained by measurements of cosmic microwave background radiation (CMB) anisotropies. Their effects on cosmic recombination may even be at the heart of the resolution of the Hubble tension. We present the most detailed analysis of the effects of PMFs on cosmic recombination to date. To this end we extend the public magneto-hydrodynamic code {\sl ENZO} with a new cosmic recombination routine, Monte-Carlo simulations of Lyman-$\alpha$ photon transport, and a Compton drag term in the baryon momentum equation. The resulting code allows us, for the first time, to realistically predict the impact of PMFs on the cosmic ionization history and the clumping of baryons during cosmic recombination. Our results identify the importance of mixing of Lyman-$\alpha$ photons between overdense- and underdense- regions for small PMF strength. This mixing speeds up recombination beyond the speed-up due to clumping. We also investigate the effects of pecuilar flows on the recombination rate and find it to be small for small PMF strengths. For non-helical PMFs with a Batchelor spectrum we find a surprising dependency of results on ultra-violet magnetic modes. We further show that the increase in the ionization fraction at low redshift by hydrodynamic baryon heating due to PMF dissipation is completely compensated by the faster recombination from baryon clumping. The present study shall serve as a theoretical foundation for a future precise comparison of recombination with PMFs to CMB data.

    ↳ astro-ph.COhep-phJCAP(2025)·22 citations
64. 64*

    Holographic transport coefficients and jet energy loss for the hot and dense quark-gluon plasma

    Joaquin Grefa🇺🇸 · Mauricio Hippert🇺🇸 · Raghav Kunnawalkam Elayavalli🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸 · Israel Portillo🇺🇸 · Claudia Ratti🇺🇸 · Romulo Rougemont🇧🇷

    We employ an Einstein-Maxwell-dilaton model, based on the gauge/gravity correspondence, to obtain the thermodynamics and transport properties for the hot and dense quark-gluon plasma. The model, which is constrained to reproduce lattice QCD thermodynamics at zero density, predicts a critical point and a first order line at finite temperature and density, is used to quantify jet energy loss through simulations of high-energy collision events.

    ↳ nucl-thhep-phhep-thnucl-exEPJ Web Conf.(2024)·3 citations
65. 65*

    Electromagnetic Entrapment in Gravity

    Pierre Heidmann🇺🇸 · Madhur Mehta🇺🇸

    We derive specific properties of electromagnetism when gravitational effects are not negligible and analyze their impact on new physics at the horizons of black holes. We show that a neutral configuration of charges in a region of high redshift, characterized by a large $g^{tt}$, produces a highly localized electromagnetic field that vanishes just beyond that region. This phenomenon implies the existence of extensive families of spacetime structures generated by electromagnetic degrees of freedom that are as compact as black holes. We construct neutral bound states of extremal black holes in four dimensions and in five dimensions, where one direction is compact. These geometries are indistinguishable from a neutral black hole, referred to as distorted Schwarzschild, except in an infinitesimal region near its horizon where the entrapped electromagnetic structures start to manifest. The five-dimensional solutions satisfy various criteria for describing black hole microstructure: they increase in size with the Newton constant, are as compact as the Schwarzschild black hole, and have an entropy that scales like $M^2$.

    ↳ hep-thgr-qchep-phJHEP(2024)·9 citations
66. 66*

    Strategies for simulating time evolution of Hamiltonian lattice field theories

    Siddharth Hariprakash🇺🇸 · Neel S. Modi🇺🇸 · Michael Kreshchuk🇺🇸 · Christopher F. Kane🇺🇸 · Christian W Bauer🇺🇸

    Simulating the time evolution of quantum field theories given some Hamiltonian $H$ requires developing algorithms for implementing the unitary operator e^{-iHt}. A variety of techniques exist that accomplish this task, with the most common technique used so far being Trotterization, which is a special case of the application of a product formula. However, other techniques exist that promise better asymptotic scaling in certain parameters of the theory being simulated, the most efficient of which are based on the concept of block encoding. In this work we study the performance of such algorithms in simulating lattice field theories. We derive and compare the asymptotic gate complexities of several commonly used simulation techniques in application to Hamiltonian Lattice Field Theories. Using the scalar \phi^4 theory as a test, we also perform numerical studies and compare the gate costs required by Product Formulas and Signal Processing based techniques to simulate time evolution. For the latter, we use the the Linear Combination of Unitaries construction augmented with the Quantum Fourier Transform circuit to switch between the field and momentum eigenbases, which leads to immediate order-of-magnitude improvement in the cost of preparing the block encoding. The paper also includes a pedagogical review of utilized techniques, in particular Product Formulas, LCU, Qubitization, QSP, as well as a technique we call HHKL based on its inventors' names.

    ↳ quant-phhep-lathep-phPRA(2025)·26 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.