Wed·Mar 5, 2025Wednesday·March 5, 2025

1. 01*

   Schwinger Current in de Sitter Space

   Mar Bastero-Gil🇪🇸 · Paulo B. Ferraz🇪🇸 · António Torres Manso🇵🇹 · Lorenzo Ubaldi🇸🇮 · Roberto Vega-Morales🇪🇸

   We study classical background electric fields and the Schwinger effect in de Sitter space. We show that having a constant electric field in de Sitter requires the photon to have a tachyonic mass proportional to the Hubble scale. This has physical implications for the induced Schwinger current which affect its IR behaviour. To study this we recompute the Schwinger current in de Sitter space for charged fermions and minimally coupled scalars imposing a physically consistent renormalization condition. We find a finite and positive Schwinger current even in the massless limit. This is in contrast to previous calculations in the literature which found a negative IR divergence. We also obtain the first result of the Schwinger current for a non-minimally coupled scalar, including for a conformally coupled scalar which we find has very similar behaviour to the fermion current. Our results may have physical implications for both magnetogenesis and inflationary dark matter production.

   hep-phastro-ph.COgr-qchep-th4 citations
2. 02*

   Momentum Flow Mechanisms and Color-Lorentz Forces on Quarks in the Nucleon

   Xiangdong Ji🇺🇸 · Chen Yang🇺🇸

   Momentum conservation in the nucleon is examined in terms of continuous flow of the momentum current density (or in short, momentum flow), which receives contributions from both kinetic motion and interacting forces involving quarks and gluons. While quarks conduct momentum flow through their kinetic motion and the gluon scalar (anomaly) contributes via pure interactions, the gluon stress tensor has both effects. The quarks momentum flow encodes the information of the color-Lorentz force density on them, and the momentum conservation allows to trace its origin to the gluon tensor and anomaly (a ``negative pressure'' potential). From the state-of-the-art lattice calculations and experimental fits on the form factors of the QCD energy-momentum tensor, we exhibit pictures of the momentum flow and the color-Lorentz forces on the quarks in the nucleon. In particular, the anomaly contributes a critical attractive force with a strength similar to that of a heavy-quark confinement potential.

   hep-phhep-latnucl-exnucl-thResearch(2026)·23 citations
3. 03*

   Production of doubly heavy baryon at the Muon-Ion Collider

   Xue-Yun Zhao🇨🇳 · Lei Guo🇨🇳 · Xu-Chang Zheng🇨🇳 · Huan-Yu Bi🇨🇳 · Xing-Gang Wu🇨🇳 · Qi-Wei Ke🇨🇳

   This study forecasts the production of doubly heavy baryons, ${\Xi }_{cc}$, ${\Xi }_{bc}$, and ${\Xi }_{bb}$, within the nonrelativistic QCD framework at the Muon-Ion Collider (MuIC). It examines two production mechanisms: photon-gluon fusion ($\gamma +g\to (Q{Q}^{\prime })[n]+\bar{Q}+\overline{Q^{\prime }}$) and extrinsic heavy quark channels ($\gamma +Q\to (Q{Q}^{\prime })[n]+\overline{Q^{\prime }}$), where $Q$ and $Q^{\prime }$ denote heavy quarks ($c$ or $b$) and $(Q{Q}^{\prime })[n]$ represents a diquark in specific spin-color configurations. The diquark fragments into ${\Xi }_{Q{Q}^{\prime }}$ baryons with high probability. For ${\Xi }_{cc}$ and ${\Xi }_{bb}$, the relevant configurations are ${[}^1{S}_0{]}_{\text{6}}$ (spin-singlet and color-sextuplet) and ${[}^3{S}_1{]}_{\bar{\text{3}}}$ (spin-triplet and color-antitriplet). For ${\Xi }_{bc}$, the configurations are ${[}^1{S}_0{]}_{\bar{\text{3}}}$, ${[}^1{S}_0{]}_{\text{6}}$, ${[}^3{S}_1{]}_{\bar{\text{3}}}$, and ${[}^3{S}_1{]}_{\text{6}}$. The study compares total and differential cross-sections for these channels, highlighting their uncertainties. The results indicate that the extrinsic heavy quark channel, particularly the ${[}^3{S}_1{]}_{\bar{\text{3}}}$ configuration, dominates ${\Xi }_{Q{Q}^{\prime }}$ production, though other diquark states also contribute significantly. Using quark masses $m_c=1.80\pm 0.10$ GeV and $m_b=5.1\pm 0.20$ GeV, the study estimates annual event yields at MuIC ($\sqrt{s}=1$ TeV, luminosity $\mathcal{L}\simeq 40$ ${\mathrm{fb}}^{-1}$) of $(3.67_{-0.91}^{+1.29})\times 10^9$ for ${\Xi }_{cc}$, $(2.24_{-0.20}^{+0.28})\times 10^8$ for ${\Xi }_{bc}$, and $(3.00_{-0.56}^{+0.64})\times 10^6$ for ${\Xi }_{bb}$. These findings suggest that MuIC will significantly enhance our understanding of doubly heavy baryons.

   hep-phCPC(2025)·3 citations
4. 04*

   Role of $a_0(980)$ in the decays $D^0\to K^{+}{K}^{-}\eta$ and ${\pi }^{+}{\pi }^{-}\eta$

   Sara Rahmani🇨🇳 · Wei Liang🇨🇳 · Yu-Wen Peng🇨🇳 · Yu Lu🇨🇳 · De-Liang Yao🇨🇳 · Chu-Wen Xiao🇨🇳

   In present work, we study the reactions $D^0\to K^{+}{K}^{-}\eta$ and $D^0\to {\pi }^{+}{\pi }^{-}\eta$, and find that the $a_0(980)$ state plays a dominant role. At the quark level, the external and internal $W$-emission mechanisms are taken into account, which can hadronize into the final states, and then the $a_0(980)$ state is generated from the final state interaction. Besides, the contributions of other intermediate resonances, such as $\rho (770)$ and $\varphi (1020)$, are also considered. We make a combined fit of the invariant mass spectra measured by the Belle and BESIII Collaborations, where the results are in good agreement with the experiments, and the signal of the $a_0(980)$ shows great significance. Besides, the antisymmetry data for the production of the $a_0(980{)}^{+}$ and $a_0(980{)}^{-}$ is described well in the combined fit.

   hep-phPRD(2025)·5 citations
5. 05*

   Comprehensive analysis of the $\gamma p\to K^{+}{\Sigma }^0(1385)$, $\gamma n\to K^{+}{\Sigma }^{-}(1385)$, and ${\pi }^{+}p\to K^{+}{\Sigma }^{+}(1385)$ reactions

   Ai-Chao Wang🇨🇳 · Neng-Chang Wei🇨🇳 · Fei Huang🇨🇳

   A comprehensive analysis of all available data on cross sections and spin-dependent observables for the $\gamma p\to K^{+}{\Sigma }^0(1385)$, $\gamma n\to K^{+}{\Sigma }^{-}(1385)$, and ${\pi }^{+}p\to K^{+}{\Sigma }^{+}(1385)$ reactions is performed within an effective Lagrangian framework. In addition to the $s$-channel $N$ exchange, $t$-channel $K$ and $K^{\ast }$ exchanges, $u$-channel $\Lambda$, $\Sigma$, and ${\Sigma }^{\ast }$ exchanges, and the interaction current, the $s$-channel contributions from a minimal set of $N$ and $\Delta$ resonances are included in constructing the reaction amplitudes to describe the data. The analysis reveals that all available data for both photon- and hadron-induced $K\Sigma (1385)$ production reactions can be simultaneously and satisfactorily reproduced when the contribution of the $s$-channel $\Delta (1930){5/2}^{-}$ resonance is taken into account. The reaction mechanisms, particularly the resonance contributions in each considered reaction, are thoroughly analyzed and discussed in detail.

   hep-phnucl-thPRD(2025)·3 citations
6. 06*

   Reexamination of eccentricity scaling of elliptic flow and incomplete thermalization scenario in heavy-ion collisions at energies available at CERN Large Hadron Collider

   Arun Kumar Yadav🇮🇳 · Partha Pratim Bhaduri🇮🇳 · Subhasis Chattopadhyay🇮🇳

   In this article, we reexamine the formulation for extraction of Knudsen number ($K$), the ratio of shear viscosity to entropy density ($\eta /s$), within the incomplete thermalization scenario, using eccentricity scaling of elliptic flow ($v_2$) of final state hadrons. Data on centrality dependence of charged hadron $v_2$ in Xe-Xe and Pb-Pb collisions, measured by ALICE and CMS collaborations at LHC are analyzed for this purpose. Results have been compared using two different models of collision namely Glauber Monte Carlo and TRENTO. The measured $v_2$, even for $\sqrt{s_{NN}}=5.02$ TeV most central Pb-Pb collisions is found to be below the ideal hydrodynamic limit by at least $15\%$. Extracted $\eta /s$ of the medium exhibit heavy dependence on the employed initial conditions. Impact of the Pade approximants based alternative formulation of the functional relation between $v_2$ and $K$ are also investigated in detail. Our studies reconfirm the importance of clarifying the initial state configuration as well as the inbuilt ambiguities in employing the transport approach based on incomplete equilibrium in a strongly coupled regime at LHC.

   hep-phhep-exEPJC(2025)·3 citations
7. 07*

   Anisotropic Lorentz invariance violation in reactor neutrino experiments

   Hai-Xing Lin🇨🇳 · Jie Ren🇨🇳 · Jian Tang🇨🇳

   Recent reactor neutrino oscillation experiments reported precision measurements of ${\sin }^{2}2{\theta }_{13}$ and $\Delta m_{ee}^2$ under the standard 3$\nu$ oscillation framework. However, inter-experiment consistency checks through the parameter goodness-of-fit test reveal proximity to the tension boundary, with the Double Chooz, RENO, and Daya Bay ensemble yielding $p_{\text{PG}}=0.14$ vs threshold $\alpha =0.1$. Anisotropic Lorentz invariance violation (LIV) can accommodate this tension by introducing a location-dependent angle ${\theta }^{\text{LIV}}$ relative to the earth's axis. It is found that anisotropic LIV improve the fit to data up to 1.9$\sigma$ confidence level significance, with the coefficient ${\mathcal{A}}_{31}^{C(0)}=2.43\times 10^{-17}\text{ MeV}$ yielding the best fit, while Parameter Goodness-of-fit (PG) is significantly improved within the LIV formalism.

   hep-phhep-exFront.Phys.(Beijing)(2026)·2 citations
8. 08*

   A common origin of two accelerating universes: inflation and dark energy

   Kunio Kaneta🇯🇵 · Kin-ya Oda🇯🇵 · Motohiko Yoshimura🇯🇵

   We develop a quantum theory of inflaton and its decay product of various gauge boson pairs to investigate the preheating towards thermalized universe. The inflaton decay into gauge-boson pairs is shown to be inevitably accompanied by tachyon-mass-like correction to inflation potential that ultimately leads to an inflaton escape out of trapped local potential minimum towards the field infinity. This gives rise to a conversion mechanism of early inflationary acceleration to a quintessence dark energy acceleration at late stages of cosmic evolution. The success of the escape depends on how standard particles are incorporated into a scheme of extended Jordan-Brans-Dicke gravity. New types of super-radiance mechanism that enhance the ending of preheating are identified and compared with the Dicke model.

   hep-phastro-ph.COgr-qc4 citations
9. 09*

   Analysis of the $q\bar{q}\to Z^{\ast }\to hA\to 4\tau$ process within the lepton-specific 2HDM at the LHC

   Yan Ma🇨🇳 · A. Arhrib🇲🇦 · S. Moretti🇬🇧 · S. Semlali🇬🇧 · Y. Wang🇨🇳 · Q.S. Yan🇨🇳

   We analyse light Higgs scalar and pseudoscalar associated hadro-production in the 2-Higgs Doublet Model (2HDM) Type-X (or lepton-specific) within the parameter space allowed by theoretical self-consistency requirements as well as the latest experimental constraints from the Large Hadron Collider (LHC), precision data and $B$ physics. Over the viable regions of such a scenario, the Standard Model-like Higgs boson discovered at the LHC in 2012 is the heavier CP-even state $H$. Furthermore, in the Type-X scenario, due to large $\tan \beta$, the lighter Higgs scalar $h$ and the pseudoscalar $A$ mainly decay into two $\tau$ leptons. Therefore, we concentrate on analysing the signal process $pp\to Z^{\ast }\to hA\to {\tau }^{+}{\tau }^{-}{\tau }^{+}{\tau }^{-}\to \ell {\nu }_{\ell }\ell {\nu }_{\ell }{\tau }_h{\tau }_h$ (where $\ell =e,\mu$ whereas ${\tau }_h$ represents the hadronic decay of the $\tau$) and explore the feasibility of conducting such a search at the LHC with a centre-of-mass energy of $\sqrt{s}=$ 14 TeV and a luminosity of $L=300f{b}^{-1}$. To suppress the huge SM background, we confine ourselves to consider the fraction of signal events with two same-sign $\tau$ leptons further decaying into same-sign leptons while the other two $\tau$ leptons decay hadronically. We find that a combination of kinematical selection and machine learning (ML) analysis will yields significant sensitivity to this process at the end of the LHC Run 3.

   hep-ph0 citations
10. 10*

    Timelike Compton scattering on a spin-0 target with kinematic twist-4 precision

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

    We calculate the kinematic twist-3 and 4 corrections to the leading order amplitude of timelike Compton scattering (TCS) on a (pseudo-)scalar target, in the recently developed framework based on the conformal operator-product expansion. This allows us to compute the complete set of helicity amplitudes of the process, in particular those that vanish at leading twist. We compare the effects of higher twist contributions to TCS with those in deeply virtual Compton scattering (DVCS). Our estimates, based on a $\pi$-meson GPD model, indicate that these contributions are sizeable and will play a crucial role in the interpretation of data from current and forthcoming experiments.

    hep-phhep-exhep-thnucl-exPRD(2025)·10 citations
11. 11*

    Searching for mirror neutrons and dark matter with cold neutron interferometry

    Antonio Capolupo🇮🇹 · Gabriele Pisacane🇮🇹 · Aniello Quaranta🇮🇹 · Francesco Romeo🇮🇹

    We report a novel neutron interferometry scheme aimed at probing the potential existence of mirror neutrons, which have been proposed as viable dark matter candidates. Our theoretical analysis demonstrates that if mirror neutrons exist, ordinary neutrons would acquire a measurable geometric phase as a result of their mixing with these mirror counterparts.

    hep-ph0 citations
12. 12*

    Constraints on 1-0 texture through neutrino phenomenology and dark matter in minimal inverse seesaw

    Jotin Gogoi🇮🇳 · Mrinal Kumar Das🇮🇳

    In this work we have realized texture zero structures of neutrino mass matrix through our study of neutrino phenomenology and dark matter. For analysing these processes, we have constructed a model in minimal inverse seesaw, ISS(2,3) by using $A_4$ discrete symmetry. The particle content of ISS(2.3) has been augmented by a scalar triplet $\eta =({\eta }_1,{\eta }_2,{\eta }_3)$. The probable dark matter candidates for this model are the neutral components of $\eta$. The three mass matices of ISS(2,3), $M_D$, $M_{NS}$ and $M_S$ contribute to the structure of light neutrino mass matrix $m_{\nu }$. Here we try to examine the impact on texture structures of $m_{\nu }$ due to different possible 2-0 structures of $M_D$. To examine further possible contraints, we have evaluated the neutrino parameters and calculated relic density of dark matter for the favourable cases. From our analysis we find that out of the fifteen possible 2-0 structures, only two of them ($M_{D3}$ and $M_{D6}$) successfully generates all the mixing angles in the allowed ranges.

    hep-ph0 citations
13. 13*

    Testing Lepton Flavor Universality at the Electron-Ion Collider

    Yongjie Deng🇨🇳 · Xu-Hui Jiang🇨🇳 · Tianbo Liu🇨🇳 · Bin Yan🇨🇳

    Measurements of $b\to c{\tau }^{-}{\bar{\nu }}_{\tau }$ transitions at colliders are highly motivated for testing lepton flavor universality (LFU), a cornerstone hypothesis of the Standard Model (SM). Potential observations of LFU violation could provide significant evidence for physics beyond the SM (BSM). The substantial production of $b$-hadrons at the Electron-Ion Collider (EIC) would highlight its potential to support LFU testing and complement studies conducted at other experimental facilities. In this paper, we study the production of $b$-hadrons in deep inelastic scattering processes at the EIC with $\sqrt{s}=100\mathrm{GeV}$. We estimate the $b$-hadron yields at the EIC to reach $\mathcal{O}(10^9)$ with an integrated luminosity of up to $10^3{\mathrm{fb}}^{-1}$. Furthermore, we perform a systematic study on various $b$-hadron decays, exploring the sensitivities of LFU-violating observables, including $R_{J/\psi }$, $R_{D_s^{(\ast )}}$ and $R_{{\Lambda }_c}$. Detailed strategies for track-based event reconstruction are investigated for these observables. We also include a discussion of the annihilation process $B_c^{+}\to {\tau }^{+}{\nu }_{\tau }$. Finally, we provide a theoretical interpretation of the projected sensitivities within the framework of low energy effective field theory (LEFT). Our analysis indicates that the EIC has the potential to constrain the relevant Wilson coefficients at $\mathcal{O}(0.1)$, offering complementary insights to other measurements.

    hep-phhep-exJHEP(2025)·9 citations
14. 14*

    WIMP-FIMP option and neutrino masses via a novel anomaly-free B-L symmetry

    Sarif Khan🇰🇷 · Hyun Min Lee🇰🇷

    We propose a novel $U(1{)}_{B-L}$ model with singlet dark matter fermions composed of WIMP and FIMP, which is anomaly-free without a need for introducing right-handed neutrinos. Fermion dark matter masses are generated after the $U(1{)}_{B-L}$ is broken spontaneously, so the Yukawa couplings for WIMP and FIMP components can be distinguished by the hierarchical values of the vacuum expectation values of the single scalar fields. Moreover, the $U(1{)}_{B-L}$ gauge boson receives a TeV-scale mass for a tiny extra gauge coupling, so it goes out of equilibrium from the rest of the model content in the early Universe. Both the $U(1{)}_{B-L}$ gauge boson and FIMP component are produced from the decays of the bath particles, and the former can decay into FIMP DM and/or WIMP DM before BBN. The WIMP component can reside in the resonance region of the Higgs bosons or dominantly annihilate into a pair of singlet-like scalars. Thus, there is a flexibility to choose a small mixing between the visible and dark sectors, thereby evading all the current direct and indirect detection bounds. Furthermore, we show that WIMP and FIMP components can coexist in suitable fractions, depending on the choice of model parameters, allowing for additional protection for WIMP DM against various experimental bounds. Finally, we identify the dimension-6 and dimension-7 operators for Majorana neutrino masses in our model, being consistent with the $U(1{)}_{B-L}$ gauge symmetry, and provide a possibility of extending the model with additional singlet fermions for neutrino masses.

    hep-phEPJC(2025)·6 citations
15. 15*

    Triplet fermion WIMP dark matter in the general supersymmetric Georgi-Machacek model

    LiangLiang Shang🇨🇳 · Yuanping Wang🇨🇳 · Xiaokang Du🇨🇳 · Bingfang Yang🇨🇳 · Stefano Moretti🇬🇧

    The supersymmetric custodial triplet model (SCTM), which is a fully-super\-symmetric generalization of the Georgi-Machacek (GM) model, is constructed by extending the Higgs sector of the minimal supersymmetric standard model by three triplet chiral superfields with hypercharge $Y=0,\pm 1$, in order to maintain the holomorphy of the superpotential and satisfy the requirements of anomaly cancellation. The global $SU(2{)}_L\otimes SU(2{)}_R$ symmetry has to be respected for the superpotential and soft supersymmetry breaking sector, where the former will only be broken by the Yukawa couplings and the latter one will be broken spontaneously to the custodial $SU(2{)}_V$ symmetry after electroweak symmetry breaking similar as the GM model. The ensuing complicated spectrum not only gives rich collider phenomenology but also provides more available Weakly Interacting Massive Particle (WIMP) Dark Matter (DM) candidates. In this paper, we explore the viability of WIMP solutions for DM in the SCTM, by considering the increasingly stringent constraints from direct detection DM experiments. Our numerical simulations show that a significant portion of the SCTM parameter space remains viable despite these constraints and will be fully tested in future experiments.

    hep-phPRD(2025)·2 citations
16. 16*

    The Electron-Ion Collider as A Prospective Facility for Pentaquark Measurements

    In Woo Park🇰🇷 · Sungtae Cho🇰🇷 · Yongsun Kim🇰🇷 · Su Houng Lee🇰🇷

    The Electron-Ion Collider provides a groundbreaking opportunity to study heavy pentaquarks with unprecedented precision, leveraging its high collision energy and beam spin polarization capabilities. As a representative case, we analyze electroproduction cross sections of Pc (4312) under different spin-parity hypotheses using the vector meson dominance model. To ensure a parameter-free approach and minimize ambiguity, we incorporate results from the LHCb and GlueX experiments. To characterize the spin and the parity of Pc (4312), we propose measuring the beam spin asymmetry and decay kinematic polarization, quantities that can be accurately determined by the ePIC detector. Our approach can be extended to investigate other heavy pentaquarks produced in electron-proton and electron-deuteron collisions, as well as to study their interactions with nuclear matter in electron-heavy ion collisions. We strongly encourage the EIC community to explore this potential and integrate pentaquark studies as a critical element of the scientific mission.

    hep-phnucl-exnucl-th0 citations
17. 17*

    Canonical treatment of strangeness and light nuclei production

    Natasha Sharma🇮🇳

    The canonical effects on strangeness and light nuclei production in high energy collisions are investigated, with a particular focus on low multiplicity events observed in small collision systems at the Large Hadron Collider (LHC), and also in low energy collisions at the Relativistic Heavy Ion Collider (RHIC). We analyzed the yields of various particles, such as pions, protons, lambdas, multi-strange hadrons and light nuclei, and their dependencies on the produced charged particle multiplicities using the Statistical Hadronization Model (SHM). Our findings indicate that the canonical treatment of strange and baryon quantum numbers are essential for describing the particle production in these collisions, particularly in small collision systems.

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

    Impact of Interference Effects on Higgs-boson Searches in the Di-top Final State at the LHC

    Henning Bahl🇩🇪 · Romal Kumar🇩🇪 · Georg Weiglein🇩🇪

    The di-top final state is an important search channel for additional Higgs bosons at the LHC. In this channel, large signal--background interference contributions can strongly distort a resonance peak as it would be expected from a pure signal contribution. Moreover, signal--signal interference effects can have a significant impact if more than one additional scalar particle is present. In this work, we perform a comprehensive model-independent analysis of the various interference contributions considering two additional heavy scalars that can mix with each other. We point out the importance of taking into account loop-level mixing between the scalars. A proper treatment of these mixing effects, which has not been previously carried out for the di-top final state, introduces additional relative phases between different parts of the amplitudes entering the interference contributions which we find to have a strong impact on the di-top invariant mass distribution. We study the interference effects both in an idealistic setting as well as taking into account experimental limitations using Monte-Carlo simulations. We demonstrate that the emerging experimental signatures can be unexpected and difficult to interpret. In particular, we point out that an experimental signature manifesting itself as an excess near the $t\bar{t}$ threshold may actually be caused by new scalar particles with much higher masses. We comment in this context on the recent excess that has been observed by the CMS collaboration near the $t\bar{t}$ threshold in their searches in the di-top final state.

    hep-phJHEP(2025)·11 citations
19. 19*

    Precision phenomenology of the PDF-BSM interplay

    Manuel Morales Alvarado🇬🇧

    The Standard Model (SM) is one of the most successful theories ever conceived, representing a triumph of human intellect and collaboration. The SM provides a very good description of visible matter, with the proton being a central part of this understanding. The structure of the proton can be parametrised in terms of parton distribution functions (PDFs), essential inputs for theoretical predictions at the Large Hadron Collider (LHC) which cannot be computed from first principles and must be obtained from fits to experimental data. Despite the remarkable success of the SM, many fundamental questions remain unanswered, motivating the search for physics beyond the Standard Model (BSM). These searches often rely on precise comparisons between theoretical predictions and experimental measurements. However, a significant challenge arises because PDFs are typically determined under SM assumptions. This approach can introduce potential biases and inconsistencies in BSM searches. Additionally, signals of BSM physics may be absorbed by the PDFs during the fitting procedure, further complicating the interpretation of the results. This PhD thesis explores the interplay between PDFs and BSM physics. We introduce the open-source release of SIMUnet, a deep learning framework designed to perform simultaneous fits of PDFs and BSM parameters, as well as to assess the potential absorption of BSM signals by the PDFs. We study the PDF-BSM interplay in the top sector and in a global dataset, and assess the absorption of BSM physics in widely used models. Additionally, we explore how BSM effects can alter the evolution of PDFs, and demonstrate the potential of interpretable machine learning techniques in symbolic regression for collider physics in general.

    hep-ph0 citations
20. 20*

    Relativistic Navier-Stokes description of the quark-gluon plasma radial flow

    Yago Bea🇪🇸

    The relativistic viscous hydrodynamic description of the quark-gluon plasma by Müller-Israel-Stewart formulations has been very successful, but despite this success, these theories present limitations regarding well-posedness and causality. In recent years, a well-behaved version of the relativistic Navier-Stokes equations has been formulated, appearing as a promising alternative in which those limitations are absent. Using this novel theory, we perform numerical simulations of a quark-gluon plasma fluid that we use to describe experimental data on the transverse momentum distribution of hadrons from central Pb-Pb collisions measured at the LHC.

    hep-phhep-thnucl-th8 citations
21. 21*

    Probing New Forces with Nuclear Clocks

    Cédric Delaunay🇫🇷 · Seung J. Lee🇰🇷 · Roee Ozeri🇮🇱 · Gilad Perez🇮🇱 · Wolfram Ratzinger🇮🇱 · Bingrong Yu🇺🇸

    Clocks based on nuclear isomer transitions promise exceptional stability and precision. The low transition energy of the thorium-229 isomer makes it an ideal candidate, as it has been excited by a vacuum-ultraviolet laser and is highly sensitive to subtle interactions. This enables the development of powerful tools for probing new forces, which we call {\it quintessometers}. In this work, we demonstrate the potential of nuclear clocks, particularly solid-state variants, to surpass existing limits on scalar field couplings, exceeding the sensitivity of current fifth-force searches at submicron distances and significantly improving equivalence-principle tests at kilometer scales and beyond. Additionally, we highlight the capability of transportable nuclear clocks to detect scalar interactions at distances beyond $10$km, complementing space-based missions.

    hep-phnucl-exphysics.atom-phquant-phPRD(2025)·10 citations
22. 22*

    Probing the flavour-blind SMEFT: EFT validity and the interplay of energy scales

    Luca Mantani🇪🇸 · Veronica Sanz🇪🇸

    The Standard Model Effective Field Theory (SMEFT) offers a systematic approach to study potential deviations from the Standard Model (SM) through higher-dimensional operators that encapsulate new physics effects. In this work, we analyze flavour-blind SMEFT contributions to flavour observables and assess their interplay with high-energy measurements from LEP and LHC. We perform global fits combining LEP precision data, flavour observables from rare B-meson decays, and LHC diboson measurements, revealing how the inclusion of different datasets breaks parameter degeneracies and enhances the sensitivity to SMEFT coefficients. Our study demonstrates that low-energy flavour observables provide reliable constraints even in flavour-blind scenarios, while high-energy measurements can be subject to EFT validity concerns due to kinematic growth. We investigate the impact of renormalization group evolution (RGE) and operator mixing across energy scales, highlighting the complementary nature of low- and high-energy datasets. The results emphasize the importance of flavour observables as robust probes of new physics and underline the necessity of global fits to avoid potential biases from limited datasets. Finally, we discuss the implications of our findings for the interpretation of global SMEFT analyses based on high-energy collider data, comparing UV models that contribute to SMEFT at tree- and loop-level.

    hep-phhep-exJHEP(2025)·10 citations
23. 23*

    Leptogenesis with perturbations in type-II and type-III seesaw models

    Iason Baldes🇫🇷

    Density perturbations have recently been shown to lead to a novel effect in the freeze-out of heavy particles called "acoustically driven freeze-out." This leads to an enhancement in the yield in standard leptogenesis. We extend this calculation to include $2\to 2$ washout processes in type-I leptogenesis and the Sommerfeld-enhanced $2\to 2$ gauge annihilations in type-II and type-III leptogenesis. These CP conserving gauge annihilations suppress the yield of heavy particles sourcing the asymmetry. We show the acoustically driven freeze-out leads to novel enhancements in the baryon asymmetry in type-II and type-III leptogenesis, already in the weak washout regime, in contrast with type-I leptogenesis.

    hep-phastro-ph.COEPJC(2025)·3 citations
24. 24*

    Impact of the cosmic neutrino background on black hole superradiance

    Gaetano Lambiase🇮🇹 · Tanmay Kumar Poddar🇮🇹 · Luca Visinelli🇮🇹

    We assess the effect of the Cosmic Neutrino Background (C$\nu$B) on superradiant instabilities caused by an ultralight scalar field around spinning black holes (BHs). When the scalar couples to neutrinos via a Yukawa interaction, thermal corrections from the C$\nu$B induce a quartic self-interaction and an effective mass term for the scalar. We show that, for Yukawa couplings as small as $y_{\varphi \nu }\sim 10^{-16}$ (for astrophysical BHs) or $10^{-20}$ (for supermassive BHs), the quartic term can quench the instability and set observable bounds, even if the scalar does not constitute dark matter. We assess the robustness of these constraints against several sources of uncertainty, including gravitational focusing of relic neutrinos, galactic clustering, and non-linear backreaction. An enhanced local neutrino density weakens the bounds by up to an order of magnitude compared to a uniform background, yet the induced self-interaction remains strong enough to significantly affect the superradiant dynamics. Our results open a new observational window on neutrino-coupled scalars via BH superradiance.

    hep-phastro-ph.COgr-qchep-thPRD(2025)·14 citations
25. 25*

    Cuscuton Bounce Beyond the Linear Regime: Bispectrum and Strong Coupling Constraints

    Amir Dehghani🇨🇦 · Ghazal Geshnizjani🇨🇦 · Jerome Quintin🇨🇦

    Cuscuton Gravity is characterized as a scalar field that can be added to general relativity without introducing any new dynamical degrees of freedom on a cosmological background. Yet, it modifies gravity such that spacetime singularities can be avoided. This has led to the Cuscuton bounce, a nonsingular cosmology that has been shown to be linearly stable, which is a rare feat. Upon introducing mechanisms known to generate a near-scale-invariant power spectrum of isocurvature perturbations in the prebounce contracting phase, we perform an extensive linear analysis of all scalar perturbations as they evolve through the Cuscuton bounce, both analytically and numerically. Then, after deriving the third-order perturbed action for our theory, we compare the magnitude of its terms (on shell) to those in the second-order action. We show that perturbativity is maintained in the infrared throughout the evolution, including through the bounce. In the ultraviolet, we show that a hierarchy of scales is maintained, with the strong coupling scale well above the relevant background energy scale at all times. We reconfirm these results by computing the three-point functions in various limits and demonstrate that the models do not have any strong coupling problems and furthermore that there is negligible non-Gaussianities on observable scales. Consequently, the primary potential source of observable non-Gaussianities may only arise from the conversion of isocurvature perturbations to curvature perturbations. The whole scenario is thus a robust, stable, weakly coupled nonsingular cosmological model, consistent with observations.

    ↳ hep-thastro-ph.COgr-qchep-phJCAP(2025)·9 citations
26. 26*

    Universal Density and Velocity Distributions of Dark Matter around Massive Black Holes

    Zi-Chang Zhang🇨🇳 · Hai-Chao Yuan🇨🇳 · Yong Tang🇨🇳

    The distribution of dark matter at the galactic center, crucial for indirect searches, remains uncertain. In particular, in the vicinity of the massive black hole in the center of a galaxy where indirect signals may be stronger, the density of a dark matter spike may undergo redistribution. Here we calculate the density surrounding Schwarzschild black holes that originate from diverse initial dark halos and estimate the velocity distribution of dark matter particles. By employing a series of Hernquist and power-law initial dark halos, we obtain a fitting formula between dark matter spikes and black hole masses. The Maxwell-Boltzmann distribution is utilized to approximate the velocity distribution of dark matter particles. As an application, taking into account dark matter self-annihilation, we assess the relic densities of dark matter spikes around black holes. We find that the relic spikes for s-wave annihilation are higher than p-wave annihilation, and the relic densities obtained for p-wave annihilation depend on the velocity distribution, varying significantly with distance. The findings shall further provide useful insights for multi-messenger dark matter detections in the future.

    ↳ astro-ph.GAastro-ph.COgr-qchep-phPRD(2025)·11 citations
27. 27*

    Meson dynamics from locally exciting a particle-conserving $Z_2$ lattice gauge theory

    Vaibhav Sharma🇺🇸 · Kaden R. A. Hazzard🇺🇸

    Quantum simulation of lattice gauge theories is an important avenue to gain insights into both particle physics phenomena and constrained quantum many-body dynamics. There is a growing interest in probing analogs of high energy collision phenomena in lattice gauge theories that can be implemented on current quantum simulators. Motivated by this, we characterize the confined mesons that originate from a local high energy excitation in a particle-conserving 1D $Z_2$ lattice gauge theory. We focus on a simple, experimentally accessible setting that does not require preparation of colliding wavepackets and isolates the effects of gauge field confinement strength and initial state energy on the nature of propagating excitations. We find that the dynamics is characterized by the propagation of a superposition of differently sized mesons. The linear confinement leads to meson size oscillations in time. The average meson size and oscillation frequency are controlled by the strength of the gauge field confinement. At a constant confinement field, the average meson length is controlled by the initial excitation's energy. Higher energies produce longer mesons and their effective mass depends strongly on their size: longer mesons propagate more slowly out of the central excitation. Mesons of different sizes get spatially filtered with time due to different speeds. We show that this phenomenology is a consequence of linear confinement and remains valid in both the strong and weak confinement limit. We present simple explanations of these phenomena supported by exact numerics.

    ↳ quant-phcond-mat.quant-gashep-lathep-phQuantum(2025)·2 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.