Wed·Jun 4, 2025Wednesday·June 4, 2025

1. 01*

   Blast-frozen Dark Matter and Modulated Density Perturbations

   Miha Nemevšek🇸🇮 · Yue Zhang🇨🇦

   First-order phase transitions (FOPT) are ubiquitous in beyond the Standard Model physics and leave distinctive echoes in the history of early universe. We consider a FOPT serving the well-motivated role of dark matter mass generation and present {\it blast-frozen dark matter} (BFDM), which transitions from radiation to non-relativistic relic in a period much shorter than the corresponding Hubble time. Its cosmological imprint are strong oscillations in the dark matter density perturbations that seed structure formation on large and small scales. For a FOPT occurring not long before the matter-radiation equality, next generation cosmological surveys bear a strong potential to discover BFDM and in turn establish the origin of dark matter mass.

   hep-phastro-ph.COPRD(2026)·0 citations
2. 02*

   Off forward non-SCHC contributions to exclusive vector quarkonium production from the "spin dependent BFKL Pomeron"

   Sanjin Benić🇭🇷 · Adrian Dumitru🇺🇸

   A novel contribution to off-forward, exclusive vector quarkonium production, ${\gamma }^{(\ast )}+p\to V+p$, at high energy is derived which corresponds to a $t$-channel exchange of a BFKL hard Pomeron, with a helicity flip of the proton. This ``spin-dependent BFKL Pomeron" is required in a consistent expansion in powers of the momentum transfer $t\approx -{\Delta }_{\perp }^2$ beyond first order. The spin-dependent Pomeron violates $s$-channel helicity conservation (SCHC) at $\mathcal{O}({\Delta }_{\perp }^2)$, and beyond. Expanding to leading twist only, it corresponds to GPD $E_g(x,t)$ for vanishing skewness. We derive explicit expressions for the eikonal BFKL amplitudes, to all orders in dipole size times momentum transfer, for all helicity configurations of the particles in the initial and final states. We also provide numerical estimates of the helicity flip two gluon exchange amplitude at moderate $x$ from a light-cone quark model of the proton. The spin dependent BFKL Pomeron could, in principle, be discovered via double spin asymmetries in $e+p\to e+p+J/\psi$ with transversely polarized proton and longitudinally polarized electron in the initial state.

   hep-phPRD(2025)·3 citations
3. 03*

   Investigating the inclusive $D^0$ photoproduction in ultraperipheral $PbPb$ collisions at the Large Hadron Collider

   Victor P. Goncalves🇧🇷 · Luana Santana🇧🇷 · Wolfgang Schäfer🇵🇱

   The inclusive $D^0$ photoproduction in $PbPb$ collisions at the center - of - mass energies of the Large Hadron Collider (LHC) is investigated considering the color dipole $S$ - matrix approach. The analytical expressions for the differential distributions are derived in the impact parameter and transverse momentum spaces and predictions for the rapidity and transverse momentum distributions are presented considering three distinct models for the unintegrated gluon distribution of the nuclear target. In particular, we compare the predictions derived assuming a linear dynamics, with and without the inclusion of nuclear effects, with those obtained by solving the running coupling Balitsky - Kovchegov equation. A comparison of these predictions with the recent (preliminary) CMS data is also performed. Our results indicate that a detailed analysis of this observable will be very useful to improve our understanding of the strong interaction theory at high energies and in a nuclear medium.

   hep-phhep-exnucl-exnucl-thPLB(2025)·6 citations
4. 04*

   Dark Matter in X-rays: Revised XMM-Newton Limits and New Constraints from eROSITA

   Shyam Balaji🇬🇧 · Damon Cleaver🇬🇧 · Pedro De la Torre Luque🇪🇸 · Miltiadis Michailidis🇩🇪

   We investigate two classes of dark matter (DM) candidates, sub-GeV particles and primordial black holes (PBHs), that can inject low-energy electrons and positrons into the Milky Way and leave observable signatures in the X-ray sky. In the case of sub-GeV DM, annihilation or decay into $e^{+}{e}^{-}$ contributes to the diffuse sea of cosmic-ray (CR) leptons, which can generate bremsstrahlung and inverse Compton (IC) emission on Galactic photon fields, producing a broad spectrum from X-rays to $\gamma$-rays detectable by instruments such as eROSITA and XMM-Newton. For PBHs with masses below $\sim 10^{17}$ g, Hawking evaporation similarly yields low-energy $e^{\pm }$, leading to comparable diffuse emission. Using the first data release from eROSITA and incorporating up-to-date CR propagation and diffusion parameters, we derive new constraints on both scenarios. For sub-GeV DM, we exclude thermally averaged annihilation cross sections in the range $\sim 10^{-27}-10^{-25}\mathrm{c}{\mathrm{m}}^3/s$ and decay lifetimes of $\sim 10^{24}-10^{25}$ s for masses between 1 MeV and 1 GeV, with eROSITA outperforming previous X-ray constraints below $\sim$ 30 MeV. For asteroid-mass PBHs, we set new bounds on the DM fraction based on their Hawking-induced emission. Finally, we revisit earlier constraints from XMM-Newton, finding that they were approximately four orders of magnitude too stringent due to the use of the instrument's geometric solid angle rather than its exposure-weighted solid angle. Upon using the exposure-weighted solid angle, we show that the revised XMM-Newton limits are slightly weaker than those from eROSITA.

   hep-phastro-ph.HEJCAP(2025)·24 citations
5. 05*

   Four-point correlation functions in axion inflation

   Hing-Tong Cho🇹🇼 · Kin-Wang Ng🇹🇼

   We study parity violation in the early universe by examining the four-point correlation function within the axion inflation model. Using an open quantum system formalism from our previous work, we calculate the influence functional to fourth order, from which we then derive the inflaton four-point correlation function. When we decompose this function using isotropic basis functions, the expansion coefficients ${\zeta }_{{\ell }^{\prime },{\ell }^{\prime \prime },{\ell }^{\prime \prime \prime }}$ naturally split into parity-even and parity-odd components. In the large $\xi$ approximation, which enhances the production of right-handed photons in the model, the derivation of these coefficients simplifies. We work out the lowest-order nonvanishing parity-odd ${\zeta }_{234}$ term which clearly indicates the presence of parity violation. Moreover, our derived values of the coefficients are consistent with recent observational data from galaxy surveys.

   hep-phastro-ph.COgr-qchep-thJCAP(2026)·6 citations
6. 06*

   Muon (and Lepton) Anomalous Magnetic Moments and Limits on Their Radii

   Dimitri Bourilkov🇺🇸

   The limits on lepton radii and contact interaction scales are used to derive limits on the deviations of lepton anomalous magnetic dipole moments (g-2)/2 from the Standard Model predictions. In the case of quadratic dependence of the deviations on the lepton mass the limits for electrons are better compared to low energy measurements, for muons somewhat weaker than the latest precision experiments, and for taus by far the best.

   hep-phhep-ex0 citations
7. 07*

   Chiral-odd generalized parton distributions for the low-lying octet baryons

   Navpreet Kaur🇮🇳 · Harleen Dahiya🇮🇳

   We have studied the chiral-odd generalized parton distributions (GPDs) for the octet baryons within the framework of diquark spectator model, emphasizing the difference arising from different quark flavors of $p$, ${\Sigma }^{+}$ and ${\Xi }^o$. The quark-quark correlator for the tensor current has been solved to investigate the transversely polarized quark dynamics using light-cone wave functions. In the forward limit, transversity distributions of all the constituent quark flavors of $p$, ${\Sigma }^{+}$, and ${\Xi }^o$ have been studied. Additionally, the lowest moment of GPD $H_T$ and the combination of GPDs $E_T$ and ${\tilde{H}}_T$ have also been investigated. Our results are comparable with other available model predictions and lattice data for the case of $p$. Furthermore, we have presented a comparative analysis of tensor charges and anomalous tensor magnetic moments for all the constituent quark flavors of the considered baryons, comparing them with available data obtained from different approaches.

   hep-phPRD(2025)·3 citations
8. 08*

   The Non-perturbative term for the Vector Form Factor of Pion Decay

   Susumu Kinpara🇯🇵

   The vector form factor of the decay ${\pi }^{+}\to \gamma +e^{+}+{\nu }_e$ is calculated by the method for the pseudovector pion-nucleon system. The non-perturbative term is taken into account by using the parameter for the self-energy of nucleon following our previous calculation of the pion form factor. The suppression of the anomalous interaction of proton in the loop integral is significant to understand the experimental value.

   hep-phnucl-th1 citation
9. 09*

   Quasinormal modes and greybody factors of charge black hole in bumblebee gravity model

   Yenshembam Priyobarta Singh🇮🇳 · Jayasri Choudhury🇮🇳 · Telem Ibungochouba Singh🇮🇳 · Dhruba Jyoti Gogoi🇮🇳

   In this paper, we investigate the Dirac field, scalar field and electromagnetic field perturbations of Reissner-Nordstorm-de Sitter (RNdS) and Reissner-Nordstorm-(anti)-de Sitter (RNAdS)-like black holes within the frame work of Einstein-bumblebee gravity. The effective potential, greybody factor and quasinormal modes (QNMs) are also explored by using Dirac equation, Klein-Gordon equation and Maxwell's equation. We find that for RNdS-like black hole increasing the Lorentz violation parameter $L$ consistently leads to decrease in the effective potential for all types of perturbations but for RNAdS case the influence of $L$ varies depending on the types of perturbation. Further for both RNdS and RNAdS-like black holes, increasing charge $Q$ reduces the effective potential in all the perturbations. The greybody factors of all the types of perturbations are also discussed. The results show that the greybody factors depend on the shape of the effective potential: higher (lower) potentials gives lower (higher) greybody factors. The QNMs frequencies of RNdS-like black hole for the massless field perturbations are discussed by using 6th order WKB approximation and Padé approximation. We also analyze the time-domain profiles of the perturbations. The effects of Lorentz violation parameter $L$ and charge $Q$ to the photon sphere radius and shadow radius are also discussed. It is noted that increasing $Q$ and $L$ reduce the rise of shadow radius for RNdS-like black hole.

   hep-ph6 citations
10. 10*

    The Study of Pole Trajectory within a bare state in the coupled channel model

    Wei Hao🇨🇳 · Jia-Jun Wu🇨🇳 · Jin-Lin Fu🇨🇳

    We investigate two-particle scattering and two-particle scattering with a bare basis state using Hamiltonian Effective Field Theory (HEFT). We analyze the distribution of two-body scattering poles in the momentum and energy planes under relativistic conditions. Compared to the non-relativistic case, there are significant differences in the distribution of bound state poles and resonance poles in the relativistic case, primarily due to the square root term in the relativistic formula. By considering pure two-particle scattering, we examine the relationship between the form factor and the number of poles. Additionally, we clearly elucidate the effects of attractive and repulsive interactions on the bound state poles and resonance poles. More importantly, we extend our model by including a bare state and explore the poles originating from the bare state or coupled channels through the trajectories of pole positions, as well as the compositeness of bound states.

    hep-phnucl-thPRD(2025)·1 citation
11. 11*

    Sea quark-gluon effect on the magnetic octupole deformation of decuplet baryons

    Preeti Bhall🇮🇳 · Ritu Garg🇮🇳 · Alka Upadhyay🇮🇳

    The magnetic octupole moment of $J^P={\frac{3}{2}}^{+}$ decuplet baryons are discussed in the statistical framework, treating baryons as an ensembles of quark-gluon Fock states. The probabilities associated with multiple strange and non-strange Fock states depict the importance of sea in spin, flavor $\&$ color space, which are further merged into statistical parameters. The individual contribution of valence and sea (scalar, vector and tensor) to the magnetic octupole moment is calculated. The symmetry breaking in both sea and valence is experienced by a suppression factor $k(1-C_l{)}^{n-1}$ and a mass correction parameter 'r', respectively. The factor $k(1-C_l{)}^{n-1}$ systematically reduces the probabilities of Fock states containing multiple strange quark pairs. The octupole moment value is obtained -ve for ${\Delta }^{++},{\Delta }^{+},{\Sigma }^{\ast +}$ and +ve for ${\Delta }^{-},{\Sigma }^{\ast -},{\Xi }^{\ast -},{\Omega }^{-}$ baryons with the domination of scalar (spin-0) sea. The computed results are compared with existing theoretical predictions, demonstrating good consistency. These predictions may serve as valuable inputs for future high-precision experiments and theoretical explorations in hadron structure.

    hep-phEPJC(2025)·0 citations
12. 12*

    Correlating lepton flavour violating $b\to s$ and leptonic decay modes in a minimal abelian extension of the Standard Model

    Pietro Colangelo🇮🇹 · Fulvia De Fazio🇮🇹 · Davide Milillo🇮🇹

    We consider an abelian extension of the Standard Model (SM) comprising a new gauge group $U(1{)}^{\prime }$, with the neutral gauge boson $Z^{\prime }$ having flavour violating couplings to quarks and leptons. The fermion content is the same as in SM except for the addition of three right-handed neutrinos. The model, proposed in \cite{Aebischer:2019blw}, describes the couplings of $Z^{\prime }$ to fermions in terms of three rational parameters ${ϵ}_{1,2,3}$ that sum to zero imposing the cancellation of the gauge anomalies. Each ${ϵ}_i$ is common to all fermions in a generation, a feature producing correlations among quark and lepton observables. We focus on $b\to s{\ell }_1^{-}{\ell }_2^{+}$ transitions for the lepton flavour conserving ${\ell }_1={\ell }_2$ and lepton flavour violating case ${\ell }_1\ne {\ell }_2$. Small deviations with respect to the SM predictions are found in the first case, which reflects a feature of the model where quark and lepton sectors prevent each other to manifest large discrepancies with respect to SM. We investigate the correlations between rare $B$ and $B_s$ decays and the leptonic processes ${\tau }^{-}\to {\mu }^{-}{\mu }^{+}{\mu }^{-}$, ${\mu }^{-}\to e^{-}\gamma$, ${\mu }^{-}\to e^{-}{e}^{+}{e}^{-}$ and the ${\mu }^{-}\to e^{-}$ conversion in nuclei. We show that the current experimental upper bounds on these four channels play an increasingly important role in constraining the branching fractions of lepton flavour violating $B$ and $B_s$ decays. While the present bound on ${\tau }^{-}\to {\mu }^{-}{\mu }^{+}{\mu }^{-}$ does not impose significant restrictions, the other three modes set progressively more stringent limits, an important information for the planned new experimental facilities.

    hep-phhep-exhep-latJHEP(2025)·3 citations
13. 13*

    Role of angular observables in probing non-standard $HZZ$ couplings at an electron-proton collider

    Pramod Sharma🇮🇳 · Ambresh Shivaji🇮🇳

    In this study, we explore various lab-frame angular observables at Large Hadron-electron Collider (LHeC) to test their sensitivity on the most general structure of the Higgs ($H$) to neutral weak boson ($Z$) coupling ($HZZ$) via the process $e^{-}p\to e^{-}Hj$ at the center of mass energy $\sqrt{s}\approx$ 1.3 TeV. The most general Lorentz structure of the $HZZ$ coupling beyond the standard model is composed of two CP-even (${\lambda }_{1Z}$ and ${\lambda }_{2Z}$) and one CP-odd (${\tilde{\lambda }}_Z$) components. In a previous study, we looked at the absolute value of azimuthal correlation ($|\Delta \varphi |$) between the final state electron and the jet to derive constraints on the non-standard $HZZ$ couplings. This choice of observable is motivated by its potential to discriminate between CP-odd and CP-even couplings in the $e^{-}p\to {\nu }_{e}Hj$ process. Since the process $e^{-}p\to e^{-}Hj$ has an electron in the final state, one can construct more angular observables. In addition to $|\Delta \varphi |$, we identify new angular observables: the sign-sensitive azimuthal correlation ($\Delta \varphi$) and the polar angle of the final state electron ($\theta$), suitable for constraining non-standard $HZZ$ coupling. Our analysis shows that these new angles improve the constraints on ${\lambda }_{2Z}$ and ${\tilde{\lambda }}_Z$ in the range of 48-67\%. We also study the potential of the asymmetry in $\Delta \varphi$ to constrain the parameters corresponding to the CP-odd coupling.

    hep-phPRD(2026)·2 citations
14. 14*

    Neutrino mass model at a three-loop level from a non-holomorphic modular $A_4$ symmetry

    Takaaki Nomura🇨🇳 · Hiroshi Okada🇨🇳

    We study a three-loop induced neutrino mass scenario from a non-holomorphic modular $A_4$ flavor symmetry and reach the minimum scenario leading predictions of the lepton masses, mixing angles, and Dirac and Majorana phases, which are shown through the chi square analyses. In addition, we discuss the lepton flavor violations, muon anomalous magnetic moment, lepton universality, and relic density of the dark matter candidate. And, we find that we need to extend our model if we satisfy the observed relic density of dark matter within the limit of perturbation where it can be done by adding one singlet scalar boson without changing predictions in neutrino sector.

    hep-phCPC(2026)·17 citations
15. 15*

    Loop-corrected Trilinear Higgs Self-Couplings in the NMSSM with Inverse Seesaw Mechanism

    Thi Nhung Dao🇻🇳 · Martin Gabelmann🇩🇪 · Margarete Mühlleitner🇩🇪

    The higher-order corrections for the SM-like Higgs boson mass and the trilinear Higgs self-couplings in the Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM) with Inverse Seesaw Mechanism are significant and highly correlated. We present here the full one-loop corrections to the trilinear Higgs self-couplings supplemented by the dominant top-Yukawa and strong coupling induced two-loop corrections from our previous calculations in the complex NMSSM. These corrections are performed consistently with the corresponding Higgs boson mass corrections. We discuss in detail the new effects from the extended neutrino and sneutrino sectors on both the trilinear Higgs self-couplings and the SM-like Higgs boson mass. When compared to the case of the NMSSM without Inverse Seesaw Mechanism, the new effects can be up to 10\% for the effective SM-like trilinear Higgs self-couplings, and up to 4.5\% for the SM-like Higgs boson mass for valid parameter points, i.e. points satisfying the Higgs data, the neutrino data, the constraints from the charged lepton flavor-violating decays, and the new physics constraints from the oblique parameters $S,T,U$. The new corrections are also included in the Higgs-to-Higgs decays for the heavy Higgs states and implemented in the new version of the Fortran code NMSSMCALC-nuSS.

    hep-phEPJC(2026)·2 citations
16. 16*

    Beyond leading twist: $\rho$ meson decay constants and distribution amplitudes in a self-consistent light-front quark model

    Ahmad Jafar Arifi🇯🇵 · Ho-Meoyng Choi🇰🇷 · Chueng-Ryong Ji🇺🇸

    In this study, we present a comprehensive analysis of decay constants and chiral-even and chiral-odd distribution amplitudes (DAs) up to twist 4 for the $\rho$ meson in the standard light-front quark model (LFQM) based on the Bakamjian-Thomas (BT) construction. For the $\rho$ meson, which possesses both longitudinal $(h=0)$ and transverse $(h=\pm 1)$ polarizations, two types of decay constants, $f_{\rho }^{\parallel }$ and $f_{\rho }^{\perp }$, arises accordingly. We demonstrate that these decay constants can be self-consistently extracted from both local ($z^{\mu }=0$) and nonlocal ($z^{\mu }\ne 0$) matrix elements $⟨0|\bar{q}(z)\Gamma q(-z)|\rho (P,h)⟩$, with $\Gamma =({\gamma }^{\mu },{\sigma }^{\mu \nu },{\gamma }^{\mu }{\gamma }_5,1)$, in a manner independent of current components, polarizations, and reference frames. In particular, we emphasize the role of nonlocal matrix elements involving axial-vector and scalar currents, where mixing between $f_{\rho }^{\parallel }$ and $f_{\rho }^{\perp }$ occurs. We show that this mixing is consistently resolved through the BT construction, ensuring the proper extraction of these decay constants. Additionally, we investigate the structure of chiral-even DAs (${\varphi }_{2;\mathrm{V}}^{\parallel },{\varphi }_{3;\mathrm{V}}^{\parallel },{\psi }_{3;\mathrm{A}}^{\perp },{\varphi }_{4;\mathrm{V}}^{\parallel }$) and chiral-odd DAs (${\varphi }_{2;\mathrm{T}}^{\perp },{\varphi }_{3;\mathrm{T}}^{\perp },{\psi }_{3;\mathrm{S}}^{\parallel },{\varphi }_{4;\mathrm{T}}^{\perp }$) beyond leading twists, and present their corresponding $\xi$-moments and Gegenbauer moments. These results provide deeper insight into the nonperturbative structure of vector mesons and demonstrate the robustness and self-consistency of the LFQM based on the BT framework.

    hep-phPRD(2025)·7 citations
17. 17*

    About electroweak domain walls in Majoron models

    Maximilian Berbig🇪🇸

    Some time ago it was claimed in "Spontaneous Breaking of Lepton Number and Cosmological Domain Wall Problem" (Phys. Rev. Lett. 122, 151301 (2019)) that non perturbative instantons of the weak interaction $\text{SU}(2{)}_{\text{W}}$ lead to the formation of domain walls in Majoron models owing to the anomaly of the spontaneously broken global lepton number $L$ symmetry $\text{U}(1{)}_L$ with respect to $\text{SU}(2{)}_{\text{W}}$. We point out that it has long been known, that this effect can be completely rotated away unless there is a source of explicit $B+L$ breaking present, where $B$ denotes baryon number. We further estimate the tiny instanton induced Majoron mass from $B+L$ breaking and analyze the cosmological impact of such domain walls including possible finite temperature effects. In general this scenario does not lead to a cosmological catastrophe and we demonstrate that the tiny instanton induced mass can act as a bias term to collapse walls induced by a larger source of lepton number breaking. Alternatively this electroweak Majoron could act as dynamical dark energy.

    hep-phastro-ph.COhep-thPRD(2026)·7 citations
18. 18*

    Renormalization of the three-flavor quark-meson diquark model

    Jens O. Andersen🇳🇴 · Mathias P. Nødtvedt🇳🇴

    We discuss the properties of the two- and three-flavor quark-meson diquark (QMD) model as a renormalizable low-energy effective model for color superconductivity in dense QCD. The effective degrees of freedom are scalars, pseudo-scalars, diquarks, and quarks. The parameters in the scalar/pseudo-scalar sector can be determined by matching the meson pole masses and decay constants to their observed values using the on-shell renormalization scheme. The remaining parameters are in the diquark sector and a priori unknown. In principle, they can be calculated from QCD, but we consider them free. We renormalize the thermodynamic potential in the 2SC phase for two flavors and in the color-flavor-locked (CFL) phase for three flavors, determining the counterterms of the couplings in the diquark sector. We derive a set of renormalization group equations for these couplings that are used to improve the thermodynamic potential. As an application, we calculate the gap and the speed of sound in the ideal CFL phase. It is shown that the gap approaches a constant as ${\mu }_B\to \infty$ and that the speed of sound relaxes to the conformal limit from above.

    hep-phnucl-th7 citations
19. 19*

    Discrete Spacetime Theories Can Explain the Muon Magnetic Moment Discrepancy

    Paul C.W. Davies🇺🇸 · Philip Tee🇺🇸

    An unsolved problem of particle physics is a discrepancy between the measured value of the muon anomalous magnetic moment and the theoretical prediction based on standard quantum electrodynamics. In this paper we show that if spacetime possesses a fundamental length scale, the ensuing modifications to the photon propagator can account for the discrepancy if the scale is chosen to be $10^{-22}$~m; the corresponding energy being about $30$~TeV. The possibility that spacetime possesses a graininess on a fine enough scale has a long history. One class of theories that develops this idea is Doubly Special Relativity (DSR), and we choose this as a model for our calculation. We note that the derived length scale is many orders of magnitude larger than the Planck length, but comparable to that of some higher dimensional gravitational theories. It is also within scope of experimental confirmation in the next generation of colliders.

    hep-phhep-thPRD(2025)·0 citations
20. 20*

    High-energy dynamics of QCD: Theoretical and phenomenological results

    Gabriele Gatto🇮🇹

    This work investigates the behavior of hadronic matter in the high-energy Regge-Gribov (semi-hard) regime of Quantum Chromodynamics (QCD), accessible through current and future colliders such as the LHC, EIC, and FCC. Central to the analysis is the Balitsky-Fadin-Kuraev-Lipatov (BFKL) formalism, with detailed treatment of the BFKL equation in both leading and next-to-leading logarithmic approximations. A major focus is placed on the computation of real next-to-leading order (NLO) corrections to the Higgs boson impact factor, incorporating finite top-quark mass effects. These corrections are essential for improving precision in Higgs production processes at large rapidity separations. The study also explores the semi-inclusive production of exotic tetraquark states, employing a hybrid framework that combines collinear and BFKL dynamics within a variable-flavor number scheme. Updated fragmentation functions for bottomonium-like states are provided, offering improved predictions at 14 TeV and 100 TeV. Additionally, the work addresses diffractive di-hadron production in the small-x saturation regime using the Color Glass Condensate (CGC) formalism, presenting preliminary leading-order analytical results.

    hep-phhep-th7 citations
21. 21*

    Reducing Hadronic Uncertainty in Low-Energy Neutral-Current Processes

    Oleksandr Tomalak🇨🇳

    We analyze the hadronic uncertainty from light-quark loops coupled to (anti)neutrino in low-energy neutral-current (anti)neutrino scattering, estimated at the $3$-$4$ permille level. This uncertainty arises from limited knowledge of the charge-isospin correlation function of quark currents. We study the charge-charge and charge-isospin correlators within $\mathrm{SU}(2)$ and $\mathrm{SU}(3)$ chiral perturbation theory (ChPT). In $\mathrm{SU}(2)$ ChPT, the two correlators are identical to all orders in the chiral and electromagnetic expansions. We further perform a leading-order $\mathrm{SU}(3)$ ChPT calculation and discuss the relevant counterterms. Our findings reduce the hadronic uncertainty in neutral-current processes such as (anti)neutrino-electron and coherent elastic (anti)neutrino-nucleus scattering by a factor $\sim 35$.

    hep-phhep-exnucl-exnucl-thPLB(2026)·3 citations
22. 22*

    Effective description of Nelson-Barr models and the theta parameter

    Gustavo H. S. Alves🇧🇷 · Celso C. Nishi🇧🇷

    Nelson-Barr theories solve the strong CP problem with CP spontaneously broken at \Lambda_{CP} and transmitted to the CP conserving version of the SM through vector-like quarks (VLQs). For an arbitrary number of CP breaking scalars and VLQs, we perform the full one-loop matching calculations at \Lambda_{CP} up to dimension five operators and the relevant matching calculations at the VLQ scale relevant to tracking the contributions to the parameter \bar{\theta}. In the EFT after the CP breaking scalars have been integrated out, we confirm that the running of \bar{\theta} at one-loop is induced by CP violating dimension five operators and similarly by dimension six operator after matching to the SMEFT. In the latter, an additional contribution enters in the matching to \bar{\theta} at tree-level due to a dimension five operator. Analyzing the experimental constraint from \bar{\theta} for generic settings, we see that a large separation between \Lambda_{CP} and the VLQ scale already suppresses the one-loop contribution to \bar{\theta} sufficiently. We confirm that a simple extension based on a nonconventional CP has a vanishing one-loop contribution to \bar{\theta}. Part of our results can be also applied to generic VLQ extensions of the SM.

    hep-phJHEP(2025)·3 citations
23. 23*

    Multi-step Strong First-Order Electroweak Phase Transitions in the Inverted Type-I 2HDM: Parameter Space, Gravitational Waves, and Collider Phenomenology

    Soojin Lee🇰🇷 · Dongjoo Kim🇰🇷 · Jin-Hwan Cho🇰🇷 · Jinheung Kim🇰🇷 · Jeonghyeon Song🇰🇷

    We investigate the electroweak phase transition (EWPT) within the inverted Type-I two-Higgs-doublet model, where the observed $125\text{GeV}$ Higgs boson is identified as the heavier \textit{CP}-even scalar $H$. Through a comprehensive parameter-space scan consistent with current theoretical and experimental constraints, we identify regions supporting strong first-order EWPTs (SFOEWPTs), including multi-step transitions. We find that two-step SFOEWPTs occur as frequently as one-step transitions, while three-step transitions can occur, albeit rarely. Crucially, the parameter spaces inducing one-step and two-step transitions are partially yet significantly separated: one-step transitions restrict the charged Higgs mass and $\tan \beta$ to $m_{H^{\pm }}\in [295,441]\text{GeV}$ and $\tan \beta \in [4.2,8.8]$, whereas two-step transitions allow $m_{H^{\pm }}\in [100,350]\text{GeV}$ and $\tan \beta \in [2.5,45.4]$. Notably, negative values of $\sin (\beta -\alpha )$ arise almost exclusively in one-step scenarios. We present the calculation of gravitational wave (GW) signal-to-noise ratios (SNRs) at LISA for multi-step EWPTs, finding that detectable GW signals ($\text{SNR}>10$) predominantly emerge from two-step transitions. Furthermore, we demonstrate that the correlation between the vacuum uplifting measure $\Delta F_0$ and ${\xi }_c$ persists in one-step transitions and breaks down in multi-step cases. Finally, we perform a dedicated collider analysis for representative SFOEWPT parameter points at the $1.5\text{TeV}$ CLIC, identifying $e^{+}{e}^{-}\to H^{+}{H}^{-}\to W^{+}{W}^{-}hh$ as a promising discovery channel. Enhanced $h\to \gamma \gamma$ branching ratios for negative $\sin (\beta -\alpha )$ motivate two complementary golden final states, $W^{+}{W}^{-}b\bar{b}{\tau }^{+}{\tau }^{-}$ and $W^{+}{W}^{-}b\bar{b}\gamma \gamma$, which demonstrate high discovery potential due to negligible Standard Model backgrounds.

    hep-phhep-exPRD(2025)·13 citations
24. 24*

    Modelling Coincident Particle Production in Ultraperipheral Heavy Ion Collisions

    L. A. Harland-Lang🇬🇧

    In this paper, we present an analysis of coincident particle production in ultraperipheral heavy ion collisions. In particular, we present the first detailed and differential predictions for coincident ${\rho }^0$ meson production in association with muon pair production, motivated by the recent ATLAS measurement of this process. These are found to describe the data very well, including the dependence of the coincidence fraction on the ZDC selection and/or other kinematic constraints on the muons. Differential predictions at the level of various kinematic variables are presented, and the calculation is made publicly available in the SuperChic MC generator. We also present general results for coincident two-photon initiated production focussing on muon and electron pair production; while the former is rather suppressed, the latter will be ubiquitous at threshold. The impact of coincident production on exclusivity vetos in ultraperipheral measurements is in addition discussed.

    hep-phhep-exnucl-exnucl-thPRD(2025)·3 citations
25. 25*

    Parametric Coincidence in the Baryon to Dark Matter Ratio from Affleck-Dine Baryogenesis and UV Freeze-in Dark Matter

    Jae Hyeok Chang🇺🇸 · Chang Sub Shin🇰🇷 · James Unwin🇺🇸

    We highlight that the observed concurrence between the baryon and dark matter relic densities can be explained via a parametric coincidence between two distinct production mechanisms: Affleck-Dine baryogenesis and dark matter UV freeze-in. In the Affleck-Dine mechanism, the baryon asymmetry is naturally proportional to the inflationary reheating temperature $T_{\mathrm{rh}}$, which also plays a critical role in setting the relic abundance of UV freeze-in dark matter. Since Affleck-Dine baryogenesis requires flat directions in the potential, the framework is inherently supersymmetric, offering compelling UV freeze-in dark matter candidates such as the gravitino. We outline scenarios in which $T_{\mathrm{rh}}$ simultaneously determines both relic abundances, resulting in a baryon-to-dark matter ratio of order unity that is largely insensitive to $T_{\mathrm{rh}}$. We also discuss the conditions required to avoid Q-ball formation or dark matter production by other mechanisms, such as NLSP decays, to preserve the parametric coincidence between baryon and dark matter abundances.

    hep-phPRD(2025)·1 citation
26. 26*

    Nonminimal infrared gravitational reheating in light of ACT observation

    Ayan Chakraborty🇮🇳 · Debaprasad Maity🇮🇳 · Rajesh Mondal🇮🇳

    Inflation is known to produce large infrared scalar fluctuations. Further, if a scalar field $(\chi )$ is non-minimally coupled with gravity through $\xi {\chi }^{2}R$, those infrared modes experience \textit{tachyonic instability} during and after inflation. Those large non-perturbative infrared modes can collectively produce hot Big Bang universe upon their horizon entry during the post-inflationary period. We indeed find that for reheating equation of state (EoS), $w_{\varphi }>1/3$, and coupling strength, $\xi >1/6$, large infrared fluctuations lead to successful reheating. We further analyze perturbative reheating by solving the standard Boltzmann equation in both Jordan and Einstein frames, and compare the results with the non-perturbative ones. Finally, embedding this infrared reheating scenario into the well-known $\alpha -$attractor inflationary model, we examine possible constraints on the model parameters in light of the latest ACT, DESI results. To arrive at the constraints, we take into account the latest bounds on tensor-to-scalar ratio, $r_{0.05}\le 0.038$, isocurvature power spectrum, ${\mathcal{P}}_{\mathcal{S}}\lesssim 8.3\times 10^{-11}$, and effective number of relativistic degrees of freedom, $\Delta N_{\mathrm{eff}}\lesssim 0.17$. Subject to these constraints, we find successful reheating to occur only for EoS $w_{\varphi }\gtrsim 0.6$, which translates to a sub-class of $\alpha -$attractor models being favored and placing them within the 2$\sigma$ region in the $n_s-r$ plane of the latest ACT, DESI data. In this range of EoS, we find that the coupling strength should lie within $2.11\lesssim \xi \lesssim 2.95$ for $w_{\varphi }=0.6$. Finally, we compute secondary gravitational wave signals induced by the scalar infrared modes, which are found to be strong enough to be detected by future GW observatories, namely BBO, DECIGO, LISA, and ET.

    ↳ astro-ph.COhep-phhep-thPRD(2025)·22 citations
27. 27*

    Euclidean-Monte-Carlo-informed ground-state preparation for quantum simulation of scalar field theory

    Navya Gupta🇺🇸 · Christopher David White🇺🇸 · Zohreh Davoudi🇺🇸

    Quantum simulators offer great potential for investigating dynamical properties of quantum field theories. However, preparing accurate non-trivial initial states for these simulations is challenging. Classical Euclidean-time Monte-Carlo methods provide a wealth of information about states of interest to quantum simulations. Thus, it is desirable to facilitate state preparation on quantum simulators using this information. To this end, we present a fully classical pipeline for generating efficient quantum circuits for preparing the ground state of an interacting scalar field theory in 1+1 dimensions. The first element of this pipeline is a variational ansatz family based on the stellar hierarchy for bosonic quantum systems. The second element of this pipeline is the classical moment-optimization procedure that augments the standard variational energy minimization by penalizing deviations in selected sets of ground-state correlation functions (i.e., moments). The values of ground-state moments are sourced from classical Euclidean methods. The resulting states yield comparable ground-state energy estimates but exhibit distinct correlations and local non-Gaussianity. The third element of this pipeline is translating the moment-optimized ansatz into an efficient quantum circuit with an asymptotic cost that is polynomial in system size. This work opens the way to systematically applying classically obtained knowledge of states to prepare accurate initial states in quantum field theories of interest in nature.

    ↳ quant-phhep-lathep-phnucl-thPRD(2026)·10 citations
28. 28*

    Caustic fringes for wave dark matter

    Andrew Eberhardt🇯🇵 · Lam Hui🇺🇸

    Wave dark matter is composed of particles sufficiently light that their de Broglie wavelength exceeds the average inter-particle separation. A typical wave dark matter halo exhibits granular substructures due to wave interference. In this paper, we explore the wave interference effects around caustics. These are locations of formally divergent density in cold collisionless systems. Examples include splashback in galaxy clusters, and tidal shells in merging galaxies, where the pile-up of dark matter close to apogee gives rise to caustics. We show that wave interference modifies the density profile in the vicinity of the caustics, giving rise to a fringe pattern well-described by the Airy function. This follows from approximating the gravitational potential as linear close to apogee. This prediction is verified in a series of numerical simulations in which the gravitational potential is computed exactly. We provide a formula expressing the fringe separation in terms of the wave dark matter mass and halo parameters, which is useful for interpreting and stacking data. The fringe separation near caustics can be significantly larger than the naive de Broglie scale (the latter set by the system's velocity dispersion). This opens up the possibility of detecting caustic fringes for a wide range of wave dark matter masses.

    ↳ astro-ph.COastro-ph.GAhep-phhep-thPRD(2025)·0 citations
29. 29*

    Study of atomic effects on electron spectrum in bound-muon decay process

    M. Y. Kaygorodov🇨🇳 · Y. S. Kozhedub🇷🇺 · A. V. Malyshev🇷🇺 · A. O. Davydov🇨🇦 · Y. Wu🇨🇳 · S. B. Zhang🇨🇳

    For the bound-muon decay process, the study of atomic effects on the electron spectrum near its endpoint is performed within the framework of the Fermi effective theory. The analysis takes into account for corrections due to finite-nuclear-size, nuclear-deformation, electron-screening, and vacuum-polarization effects, all of which are incorporated self-consistently into the Dirac equation. Furthermore, the nuclear-recoil correction to the muon binding energy is included. Calculations are carried out for the isotopes of C, Al, and Si, which are of a particular importance for forthcoming experiments aimed at search for the charged-lepton flavor-violating process of muon-to-electron conversion in a nuclear field.

    ↳ physics.atom-phhep-phCPC(2026)·4 citations
30. 30*

    Testing strong-field QED with the avalanche precursor

    A. A. Mironov🇫🇷 · S. S. Bulanov🇺🇸 · A. Di Piazza🇺🇸 · M. Grech🇫🇷 · L. Lancia🇫🇷 · S. Meuren🇫🇷 · J. Palastro🇺🇸 · C. Riconda🇫🇷 · H. G. Rinderknecht🇺🇸 · P. Tzeferacos🇺🇸 · G. Gregori🇬🇧

    A two-beam high-power laser facility is essential for the study of one of the most captivating phenomena predicted by strong-field quantum electrodynamics (QED) and yet unobserved experimentally: the avalanche-type cascade. In such a cascade, the energy of intense laser light can be efficiently transformed into high-energy radiation and electron-positron pairs. The future 50-petawatt-scale laser facility NSF OPAL will provide unique opportunities for studying such strong-field QED effects, as it is designed to deliver two ultra-intense, tightly focused laser pulses onto the interaction point. In this work, we investigate the potential of such a facility for studying elementary particle and plasma dynamics deeply in the quantum radiation-dominated regime, and the generation of QED avalanches. With 3D particle-in-cell simulations, we demonstrate that QED avalanche precursors can be reliably triggered under realistic laser parameters and layout (namely, focusing $f/2$, tilted optical axes, and non-ideal co-pointing) with the anticipated capabilities of NSF OPAL. We demonstrate that seed electrons can be efficiently injected into the laser focus by using targets of three types: a gas of heavy atoms, an overcritical plasma, and a thin foil. A strong positron and high-energy photon signal is generated in all cases. The cascade properties can be identified from the final particle distributions, which have a clear directional pattern. At increasing laser field intensity, such distributions provide signatures of the transition, first, to the radiation-dominated interaction regime, and then to a QED avalanche. Our findings can also be used for designing related future experiments.

    ↳ physics.plasm-phhep-phPhys.Plasmas(2025)·2 citations
31. 31*

    Testing Variational Perturbation Theory for Effective Actions Using the Gaudin-Yang Model

    Pranav Sharma🇺🇸 · R. J. Furnstahl🇺🇸

    The background field formalism based on effective actions is a compelling framework for developing an effective field theory for nuclear density functional theory. Among the challenges in carrying out this development is handling both the particle-hole and pairing channels beyond the mean-field level, which includes how to incorporate collective degrees of freedom. Here we use the exactly solvable one-dimensional Gaudin-Yang model as a theoretical laboratory to explore candidate approaches. We compare Variational Perturbation Theory (VPT) to ordinary many-body perturbation theory and the inversion method, all to second order in their respective expansions, and verify issues with Hubbard-Stratonovich auxiliary fields. VPT outperforms the other approaches at this level over a wide range of densities. The next steps to extend this approach toward nuclei are outlined.

    ↳ nucl-thcond-mat.otherhep-phPRC(2025)·1 citation
32. 32*

    High-order anisotropic flow and nonlinear hydrodynamic responses

    Owen Horecny🇺🇸 · Chun Shen🇺🇸

    In this work, we study the charged hadron anisotropic flow coefficients $v_n$ (up to $n=12$) using high-statistics event-by-event simulations of Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ and $5.36$~TeV, employing the IP-Glasma + MUSIC + UrQMD hybrid approach. The power spectra of anisotropic flow coefficients ($v_n\{2\}$ vs. $n$) are compared with the ALICE measurements from central to 50% centrality. To understand the various sources contributing to the high-order $v_n$ coefficients, we analyze the nonlinear mode coefficients for high-order anisotropic flow coefficients using different approximations and make comparisons with available measurements.

    ↳ nucl-thhep-phnucl-exPRC(2025)·1 citation
33. 33*

    Probing Dark Matter Spike with Gravitational Waves from Early EMRIs in the Milky Way Center

    Chen Feng🇨🇳 · Yong Tang🇨🇳 · Yue-Liang Wu🇨🇳

    Cold dark matter may form dense structures around supermassive black holes (SMBHs), significantly influencing their local environments. These dense regions are ideal sites for the formation of extreme mass-ratio inspirals (EMRIs), in which stellar-mass compact objects gradually spiral into SMBH, emitting gravitational waves (GWs). Space-based gravitational-wave (GW) observatories such as LISA and Taiji will be sensitive to these signals, including early-stage EMRIs (E-EMRIs) that persist in the low-frequency band for extended periods. In this work, we investigate the impact of dark matter-induced dynamical friction on E-EMRIs in the Milky Way Center, model its effect on the trajectory, and calculate the resulting modifications to the GW spectrum. Our analysis suggests that this influence might be sizable and lead to detectable deviations in the spectrum, namely suppression at low frequencies and enhancement at high frequencies, therefore providing a potential probe for dark matter with future GW detectors in space, such as LISA and Taiji.

    ↳ astro-ph.GAastro-ph.COgr-qchep-phPRD(2026)·11 citations
34. 34*

    Modeling an internal structure of a black hole using a thermodynamic quasi-particle model

    Sergey Bondarenko🇮🇱 · Dima Cheskis🇮🇱 · Raghvendra Singh🇮🇱

    We develop an effective thermodynamic model for a black-hole interior composed of scalar quasiparticles. The interior is represented by two regions: a dense core and a surrounding crust, whose properties are controlled by the quasiparticle kinetics. In the core, quasiparticles are assumed to have vanishing classical kinetic energy, so the total core energy is dominated by a potential-energy functional $U(N)$ that depends only on the quasiparticle number $N$. As a consequence, the appropriate intensive variable governing the core thermodynamics is an inverse-temperature--like parameter $\beta$, introduced as the thermodynamic conjugate to $U$; it replaces the usual kinetic temperature $T$ in the core equations of state and can drive the core pressure and energy density negative in the relevant regime. Different core states are further characterized by the mean occupation number $\eta$. In the crust, quasiparticles remain trapped at finite kinetic temperature, and the no-escape condition is implemented via a truncation of the phase-space integrals, yielding an explicit analytic coupling between thermodynamics and gravity. The resulting framework provides a unified quasiparticle description of core and crust, clarifies the thermodynamic origin of negative pressure/energy in the interior, and provides an effective thermodynamic setting for exploring how semiclassical or microscopic resolutions of the singularity problem might be constrained.

    ↳ gr-qccond-mat.stat-mechhep-phAnnals Phys.(2026)·2 citations
35. 35*

    Sensitivity of a Gigahertz Fabry-Pérot Resonator for Axion Dark Matter Detection

    Jacob Egge🇩🇪 · Manuel Meyer🇩🇰

    Axions are hypothetical pseudo-Nambu Goldstone bosons that could explain the observed cold dark matter density and solve the strong CP problem of quantum chromodynamics (QCD). Haloscope experiments commonly employ resonant cavities to search for a conversion of axion dark matter into photons in external magnetic fields. As the expected signal power degrades with increasing frequency, this approach becomes challenging at frequencies beyond tens of Gigahertz. Here, we propose a novel haloscope design based on an open Fabry-Pérot resonator. Operating a small-scale resonator at cryogenic temperatures and at modest magnetic fields should already lead to an unparalleled sensitivity for photon-axion couplings $g_{a\gamma }\gtrsim 3\times 10^{-12}{\mathrm{GeV}}^{-1}$ at 35GHz. We demonstrate how this sensitivity could be further improved using graded-phase mirrors and sketch possibilities to probe benchmark models of the QCD axion.

    ↳ physics.ins-detastro-ph.IMhep-exhep-phPRD(2025)·0 citations

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