Wed·Apr 23, 2025Wednesday·April 23, 2025

1. 01*

   Inflationary Gravitational Waves and Laboratory Searches as Complementary Probes of Right-handed Neutrinos

   Zafri A. Borboruah🇮🇳 · Frank F. Deppisch🇬🇧 · Anish Ghoshal🇵🇱 · Lekhika Malhotra🇮🇳

   We analyze the damping of inflationary gravitational waves (GW) that re-enter the Hubble horizon before or during a post-inflationary era dominated by a meta-stable, right-handed neutrino (RHN), whose out-of-equilibrium decay releases entropy. Within a minimal type-I seesaw extension of the Standard Model (SM), we explore the conditions under which the population of thermally produced RHNs remain long-lived and cause a period of matter-domination. We find that the suppression of the GW spectrum occurs above a characteristic frequency determined by the RHN mass and active-sterile mixing. For RHN masses in the range $0.1$-$10$ GeV and mixing $10^{-12}\lesssim |V_{eN}{|}^2\lesssim 10^{-5}$, we estimate such characteristic frequencies and the signal-to-noise ratio to assess the detection prospects in GW observatories such as THEIA, $\mu$-ARES, LISA, BBO and ET. Additionally we use LIGO data to put upper bounds on the reheating temperature after inflation, for a given blue-tilted GW spectrum. We find complementarity between GW signals and laboratory searches in SHiP, DUNE and LEGEND-1000. Notably, RHN masses of $0.2$-$2$ GeV and mixing $10^{-10}\lesssim |V_{eN}{|}^2\lesssim 10^{-7}$ are testable in both laboratory experiments and GW observations. Additionally, GW experiments can probe the canonical seesaw regime of light neutrino mass generation, a region largely inaccessible to laboratory searches.

   hep-phastro-ph.COPRD(2025)·10 citations
2. 02*

   Light front holographic QCD theory in the generalized uncertainty principle framework

   Fidele J. Twagirayezu🇺🇸

   In this article, we develop the framework of light-front holographic QCD in the presence of a minimal length scale by incorporating the Generalized Uncertainty Principle (GUP) into the QCD Lagrangian. From this modified theory, we derive a GUP-corrected light-front holographic QCD (LFH QCD) equation and obtain the corresponding hadronic mass spectrum. Our results show that the hadronic mass spectrum acquires an additional GUP-dependent term that increases the masses. This mass enhancement leads to significantly improved agreement between the theoretical predictions and experimental data.

   hep-ph1 citation
3. 03*

   Pole trajectories from $S$- and $P$-wave $D{\bar{D}}^{\ast }$ interactions

   Xiao-Xiao Chen🇨🇳 · Zuo-Ming Ding🇨🇳 · Jun He🇨🇳

   In this work, we investigate the $S$- and $P$-wave interactions of the $D{\bar{D}}^{\ast }$ system within the framework of the quasipotential Bethe-Salpeter equation, with the aim of exploring possible molecular states and their corresponding pole trajectories. The interaction potentials are constructed using the one-boson-exchange model, incorporating the exchanges of $\pi$, $\eta$, $\rho$, $\omega$, $\sigma$, and $J/\psi$ mesons, based on heavy quark effective Lagrangians. The poles of the scattering amplitude are analyzed and their evolution on two Riemann sheets is systematically traced as the cutoff parameter increases up to 5 GeV. We identify four molecular states arising from the $S$-wave $D{\bar{D}}^{\ast }$ interaction. Among them, the bound state with quantum numbers $I^G(J^{PC})=0^{+}(1^{++})$ corresponds well to the experimentally observed $X(3872)$, while its isovector partner with $I^G(J^{PC})=1^{-}(1^{++})$ is found to exist only as a virtual state. Additionally, a $0^{-}(1^{+-})$ state appears as a bound state. The isovector $1^{+-}$ state, which may be associated with the $Z_c(3900)$, is observed to evolve from a bound state to a virtual state as the interaction strength decreases. For the $P$-wave $D{\bar{D}}^{\ast }$ interaction, the structure $G(3900)$ recently observed at BESIII is likely connected to a $0^{-}(1^{--})$ state. A $0^{+}(0^{-+})$ state is also predicted in this channel. Both can appear as either resonance or bound/virtual state depending on the interaction strength.

   hep-phPRD(2025)·9 citations
4. 04*

   Warm multi natural inflation

   Asuka Ito🇯🇵 · Rudnei O. Ramos🇧🇷

   Multi-natural inflation is studied in the context of warm inflation. We study the warm multi-natural inflation scenario with both linear and cubic temperature-dependent dissipation coefficients. The model is motivated by axion-like inflation models with coupling to non-Abelian gauge fields through a dimension-five coupling and dissipation originating from sphaleron decay in a thermal bath. Both cases of dissipation coefficients can be compatible with current observations. In the case of the cubic dissipation coefficient, we find that the curvature perturbation starts to grow suddenly when a transition from a weak dissipation to a strong dissipation regime occurs at the later stage of the inflation. We also show that such rapid growth of the curvature perturbation on small scales gives rise to abundant scalar induced gravitational waves, which may be detectable with future gravitational wave detectors such as DECIGO and ET. On the other hand, there are also other parameter regions of the model, in the warm inflation regime of weak to strong dissipation and with sub-Planckian axion decay constant, that can lead to overproduction of primordial black holes on small scales, which are constrained by nucleosynthesis bounds, thus ruling out the model in this region of parameters.

   hep-phastro-ph.COgr-qchep-thJCAP(2025)·9 citations
5. 05*

   Lorentz Violation: Loop-Induced Effects in QED and Observational Constraints

   Zurab Kepuladze🇬🇪

   Lorentz invariance is a cornerstone of modern physics, yet its possible violation remains both theoretically intriguing and experimentally significant. In this work, using quantum electrodynamics as an example, we explore how Lorentz invariance violation, introduced into a specific sector of the theory, spreads through loop corrections, modifying the propagation and dispersion relations of other particles. Self-energy and vacuum polarization graphs reveal how LIV effects transfer across sectors, influencing particle kinematics. Due to these loop effects, constraints from cosmic-ray observations and other Earth-based experiments impose limits on induced LIV parameters that would otherwise be less constrained. We show that while interaction-based LIV effects require unrealistically large parameters for detection, modifications to dispersion relations can be probed down to $\delta \sim 10^{-8}\text{ to }10^{-9}$ at the LHC. This suggests that accelerator-based resonance studies provide a promising avenue for stringent LIV constraints, potentially rivaling astrophysical observations.

   hep-ph1 citation
6. 06*

   Monte Carlo simulation of GRB data to test Lorentz-invariance violation

   Hanlin Song🇨🇳 · Bo-Qiang Ma🇨🇳

   Lorentz-invariance violation (LV) at energy scales approaching the Planck regime serves as a critical probe for understanding quantum gravity phenomenology. Astrophysical observations of gamma-ray bursts (GRBs) present a promising avenue for testing LV-induced spectral lag phenomena; however, interpretations are complicated by degeneracies between LV effects and intrinsic emission delays. This study systematically investigates three competing time delay models: Model A (LV delay combined with a constant intrinsic delay), Model B (energy-dependent intrinsic delay without LV), and Model C (LV delay combined with energy-dependent intrinsic delay). We utilize mock GRB datasets generated under distinct delay mechanisms and employ Bayesian parameter estimation on simulated observations of 10 GRBs. Our findings demonstrate that Model C consistently recovers input parameters across all datasets. In contrast, Models A and B struggle to reconcile data generated under alternative mechanisms, particularly when confronted with high-energy TeV photons from GRB 190114C and GRB 221009A. Our analysis confirms that the incorporation of energy-dependent intrinsic delays in Model C is essential for establishing robust LV constraints, effectively resolving prior ambiguities in the interpretation of multi-GeV and TeV photon emissions. The results validate Model C as a generalized framework for future LV searches, yielding a subluminal LV scale of \(E_{\rm LV} \simeq 3 \times 10^{17}\) GeV based on realistic datasets. These findings are consistent with earlier constraints derived from Fermi-LAT datasets. This work underscores the necessity for joint modeling of LV and astrophysical emission processes in next-generation LV studies utilizing observatories such as LHAASO and CTA.

   hep-phastro-ph.HEgr-qcPRD(2025)·7 citations
7. 07*

   Susceptibilities of conserved charges of hadronic matter

   Somenath Pal🇮🇳

   An effective description of hadronic matter in terms of "effective free particles" is presented. Repulsive interactions among the hadrons have been modelled by Excluded volume correction by considering the hadrons as liquid drops, whose volume is inversely proportional to the cube root of the mass of the species. The only adjustable parameter in the model is pion radius. We get better agreement to the lattice results as compared to the previous studies.

   hep-ph0 citations
8. 08*

   Spin structure of spin-1 charmonium states near $T_c$

   HyungJoo Kim🇯🇵

   We investigate the spin structure of the $1^{--}$ and $1^{++}$ charmonium states near the critical temperature using QCD sum rules. To this end, we compute the contribution of the dimension-4 twist-2 gluon operator to the two-point function of heavy vector and axial vector currents in a rotating frame. As temperature increases, the quark spin contribution slightly increases, while the quark orbital angular momentum decreases by a comparable amount. The gluon contribution remains nearly unchanged. These thermal changes cancel each other, ensuring that the total spin is preserved even at finite temperature.

   hep-phnucl-th1 citation
9. 09*

   Doubly-charmed pentaquark states in a mass splitting model

   Shi-Yuan Li🇨🇳 · Yan-Rui Liu🇨🇳 · Cheng-Rui Shu🇨🇳 · Zong-Guo Si🇨🇳

   Concentrating on the mass differences relative to $P_{\psi }^N(4312{)}^{+}$, we systematically investigate the spectra of doubly-charmed pentaquark states in the compact $ccqq\bar{q}$ ($q=u,d,s$) configuration. The assumption that the observed $P_{\psi }^N(4312{)}^{+}$ is a compact hidden-charm pentaquark with $I(J^P)=\frac{1}{2}({\frac{3}{2}}^{-})$ is adopted. We also study the properties of strong decays within a simple rearrangement scheme. The results indicate that the $I(J^P)=\frac{1}{2}({\frac{1}{2}}^{-})$ $ccnn\bar{n}$ with $I_{nn}=0$ where $n$ denotes $u$ or $d$ quark, $I(J^P)=0({\frac{1}{2}}^{-})$ $ccnn\bar{s}$, and $I(J^P)=0({\frac{1}{2}}^{-})$ $ccns\bar{n}$ ground states should be stable.

   hep-phhep-exEur.Phys.J.Plus(2025)·3 citations
10. 10*

    Quantum Entanglement Autodistillation in Baryon Pair Decays

    Hai-Long Feng🇨🇳 · Hao Tang🇨🇳 · Wu-zhong Guo🇨🇳 · Qin Qin🇨🇳

    We study the spin-entangled mixed state of a spin-1/2 baryon-antibaryon pair produced in the process e+e- to J/psi, psi(2S) to BBbar. We demonstrate that the spin entanglement of the system can increase following the decays B to b + M and Bbar to bbar + Mbar, where b and bbar are spin-1/2 baryons and M, Mbar are spin-0 mesons. This phenomenon, known as entanglement autodistillation, represents a probabilistic amplification of entanglement during the decay process. We analyze the underlying mechanism and show that it depends only on the initial state of the BBbar system and the decay parameter alphaD, but not on the phase parameter phiD.

    hep-phhep-exquant-phPRD(2025)·5 citations
11. 11*

    Searching for heavy vector-like B quark via pair production in fully hadronic channels at the CLIC

    Shuo Yang🇨🇳 · Yi-Hang Wang🇨🇳 · Peng-Bo Zhao🇨🇳 · Ji-Long Ma🇨🇳

    Vector-like quarks (VLQs) are introduced in many new physics senarios beyond the Standard Model (SM) to address some problems faced by SM. In this paper, we explore the pair production of TeV-scale vector-like B quark (VLQ-$B$) at the future 3 TeV Compact Linear Collider (CLIC) in simplified effective lagrangian framework. We consider the decay modes of $B\to bZ$ and $B\to bh$ followed by hadronic decay of $Z$ and $h$ bosons. The large mass of VLQ-$B$ will induce highly boosted bosons $Z$ or $h$ which are more likely to form as fat-jets. By performing a rapid detector simulation of the signal and background events and clustering the jets with a large radius R, signal-background analyses are carried out. And the exclusion limit at the 95\% confidence level and the 5$\sigma$ discovery prospects are obtained with an integrated luminosity of 5${\text{ab}}^{-1}$.

    hep-phCPC(2025)·5 citations
12. 12*

    New rare meson decay constraints on a light vector in $U(1{)}_{B-L},U(1{)}_R$ and the dark photon

    Osamu Seto🇯🇵 · Takashi Shimomura🇯🇵 · Shinsuke Yoshida🇨🇳

    We evaluate constraints from flavor changing rare meson decays to a light vector boson $X$, followed by the decay of the on-shell $X$ into the SM fermions. The flavor changing meson decay emitting the light $X$ is induced by loop processes where the up-type quarks, the $W$ boson, or charged scalar bosons are running inside loops. We calculate all one-loop diagrams with neglecting all masses of light quarks except for the top quark in a general anomaly free extra $U(1)$ model. Our theoretical evaluation of the branching ratio of charged $B$ meson decay and charged kaon decay is compared to experimental results, and we derive new constraints for dark photon, $U(1{)}_{B-L}$ and $U(1{)}_R$ models.

    hep-phJHEP(2025)·4 citations
13. 13*

    Effects of the Matter Potential at One-Loop Level on Neutrino Oscillations in Long-Baseline Experiments

    Jihong Huang🇨🇳 · Tommy Ohlsson🇸🇪 · Sampsa Vihonen🇸🇪 · Shun Zhou🇨🇳

    In this work, we investigate in a quantitative way how much radiative corrections to the matter potential for neutrino oscillations can impact the sensitivity to neutrino mass ordering in long-baseline accelerator experiments. Using numerical simulations for the future experiment DUNE, we find that the statistical significance for excluding the incorrect mass ordering can be enhanced by about $0.4\sigma$ if a one-loop correction of $2.0\%$ -- based on the Fermi coupling constant $G_{\mu }^{}$ derived from measurements of muon lifetime -- is included. The radiative corrections at one-loop level lead to resolving the neutrino mass ordering at $5\sigma$ confidence level 4-9 days earlier than at tree level. In contrast, the sensitivity to leptonic CP violation in DUNE is essentially unchanged. Finally, we emphasize that one-loop corrections should be incorporated into analyses of future neutrino oscillation data in a consistent and systematic manner.

    hep-phPRD(2025)·3 citations
14. 14*

    Probing New Physics Through CP Violation in $B_{(s)}\to V{\mu }^{+}{\mu }^{-}$ Decays

    Robert Fleischer🇳🇱 · Martijn van Hamersveld🇳🇱 · Tim Kortekaas🇳🇱 · Anders Rehult🇳🇱 · K. Keri Vos🇳🇱

    Rare decays of the kind $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$ and $B_s\to \varphi {\mu }^{+}{\mu }^{-}$ are key players for testing the Standard Model. The current experimental data for their decay rates and angular observables show tensions with the theoretical predictions that may be indications of New Physics. We present a strategy to extract the relevant short-distance coefficients in the presence of new sources of CP violation, utilizing a synergy with $B\to K{\mu }^{+}{\mu }^{-}$ decays. Using the current data as a guideline, we illustrate the new method to determine the complex coefficients $C_9^{(\prime )}$ and $C_{10}^{(\prime )}$ using only four angular observables. Interestingly, the current experimental picture leaves significant room for CP-violating New Physics. We discuss also the link to leptonic $B_s^0\to {\mu }^{+}{\mu }^{-}$ decays. We are looking forward to the implementation of these strategies at the future high-precision frontier of flavour physics.

    hep-phhep-thJHEP(2026)·6 citations
15. 15*

    Non-Renormalizable SU(5) GUTs: Leptoquark-Induced Neutrino Masses

    Ilja Doršner🇭🇷 · Mijo Matković🇭🇷 · Shaikh Saad🇸🇮

    We revisit the doublet-triplet splitting problem within the $SU(5)$ gauge group framework to advocate a viable regime with the light scalar leptoquark of the doublet-triplet splitting notoriety that is compatible with the current experimental bounds on partial proton decay lifetimes. We explicitly demonstrate, through a consistent use of higher-dimensional operators, how to implement suppression of baryon number violating interactions of the aforementioned color triplet. Our study thus offers an alternative approach to the doublet-triplet splitting problem as it removes a need for an extreme mass hierarchy between the partners residing in the same representation. We furthermore pursue two different extensions of two distinct symmetry breaking scenarios of $SU(5)$, one with a $24$-dimensional representation and the other one with a $75$-dimensional representation, to produce comparative study of novel consequences for the gauge coupling unification and the one-loop level neutrino mass generation. Our results point towards qualitatively novel $SU(5)$ scenarios, where the light scalar leptoquarks, responsible for the neutrino mass generation, might be even accessible at colliders and thus serve as an accelerator accessible portal to the high-scale physics.

    hep-phPRD(2025)·4 citations
16. 16*

    Linking the KM3-230213A Neutrino Event to Dark Matter Decay and Gravitational Wave signals

    Sarif Khan🇰🇷 · Jongkuk Kim🇰🇷 · Pyungwon Ko🇰🇷

    The KM3NeT collaboration recently reported the detection of an ultra-high-energy (UHE) neutrino event, dubbed KM3-230213A. This is the first observed neutrino event with energy of the order of $\mathcal{O}(100)\mathrm{PeV}$, the origin of which remains unclear. In this paper, we interpret this high energy neutrino event in terms of the Dirac fermion dark matter (DM) $\chi$ decays via the right-handed (RH) neutrino portal assuming the Type-I seesaw mechanism for neutrino masses and mixings. Furthermore, the Dirac fermion dark matter $\chi$ is assumed to be charged under $U(1{)}_X$ dark gauge symmetry, which is spontaneously broken by the vacuum expectation value (VEV) of the dark Higgs $\Phi$. In this scenario, DM can decay into a pair of Standard Model (SM) particles, such as neutrinos, leptons, and gauge bosons via the RH neutrino portals for $v_{\Phi }\gg m_{\chi }$. Then we can reply on the HDMSpectra package to generate the neutrino and $\gamma$-ray spectra from heavy DM decays. If the DM mass is around $440\mathrm{PeV}$ with a lifetime $5\times 10^{29}$ sec, it can account for the KM3-230213A event. However, such heavy DM cannot be produced through the thermal freeze-out mechanism due to overproduction and violation of unitarity bounds. We focus on the UV freeze-in production of DM through a dimension-5 operator, which helps in producing the DM dominantly in the early Universe. Finally, the large value of the dark Higgs field VEV opens up the intriguing possibility of generating gravitational waves (GWs) spectra from cosmic strings. We have found a reasonable set of parameter values that can address the KM3NeT signal, yield the correct value of the DM relic density through freeze-in mechanism, and allow for the possible detection of GW signal at the future detectors.

    hep-phastro-ph.HEJCAP(2025)·17 citations
17. 17*

    Reinforcement Learning and Metaheuristics for Feynman Integral Reduction

    Mao Zeng🇬🇧

    We propose new methods for optimizing the integration-by-parts (IBP) reduction of Feynman integrals, an important computational bottleneck in modern perturbative calculations in quantum field theory. Using the simple example of one-loop massive bubble integrals, we pose the problem of minimizing the number of arithmetic operations in reducing a target integral to master integrals via the Laporta algorithm. This is a nontrivial combinatorial optimization problem over the ordering of IBP equation generation (from pairs of seed integrals and IBP operators) and the ordering of integral elimination. Our first proposed method is reinforcement learning, which involves an agent interacting with an environment in a step-by-step manner and learning the best actions to take given an observation of the environment (in this case, the current state of the IBP reduction process). The second method is using metaheuristics, e.g. simulated annealing, to minimize the computational cost as a black-box function of numerical priority values that control the orderings. For large-scale problems, the number of free parameters can be compressed by using a small neural network to assign priority values. Remarkably, with almost no human guidance, both methods lead to IBP reduction schemes that are competitive with the most efficient human-designed algorithms. We also found interpretable features in the AI results that may be applicable to more complicated problems.

    hep-phhep-thPRD(2025)·19 citations
18. 18*

    MOSAIC: Magnonic Observations of Spin-dependent Axion-like InteraCtions

    Clarence Chang🇺🇸 · T. J. Hobbs🇺🇸 · Dafei Jin🇺🇸 · Yi Li🇺🇸 · Marharyta Lisovenko🇺🇸 · Valentine Novosad🇺🇸 · Zain H. Saleem🇺🇸 · Tanner Trickle🇺🇸 · Gensheng Wang🇺🇸

    We introduce an array-scalable, magnon-based detector (MOSAIC) to search for the spin-dependent interactions of electron-coupled axion dark matter. These axions can excite single magnons in magnetic targets, such as the yttrium iron garnet (YIG) spheres used here, which are subsequently sensed by the detector. For MOSAIC, this sensing is implemented by coupling the magnons in the YIG spheres to magnetic-field-resilient single-electron charge-qubits, whose state is then interrogated with a quantum non-demolition measurement. Using standard superconducting fabrication techniques, MOSAIC can integrate many YIG sphere-qubit sensors, forming a large detector array. We outline the detector design and operation, and determine its sensitivity to axion dark matter. We find that a detector built with available technology will exceed the sensitivity of previous ferromagnetic haloscopes, and provides a platform where further improvements in performance would search for electron-coupled axion dark matter in unexplored parameter space.

    hep-phhep-exphysics.ins-detPRD(2026)·5 citations
19. 19*

    Universality of entanglement in gluon dynamics

    Claudia Núñez · Alba Cervera-Lierta🇪🇸 · José Ignacio Latorre🇸🇬

    Entanglement of fundamental degrees of freedom in particle physics is generated ab initio in scattering processes. In the case of a pure $SU(N)$ gauge theory, two gluons in a product state can be entangled in their polarizations as the result of three- and four-gluon vertex interactions. We find that entanglement is only produced when the initial product state have opposite polarizations, and that maximal entanglement is generated when the outgoing particles form an angle of $\frac{\pi }{2}$ with respect to the incoming ones. A surprising result is that the amount of entanglement among gluon polarizations is independent of the gauge group at any angle and, thus, of the color degree of freedom. Universality of entanglement for any gauge group emerges. It is also found that a small deviation of the relative weight between three- and four-gluon vertices would prevent the generation of maximal entanglement. This can be seen as a small piece of a possible it from qubit principle underlying fundamental interactions, that is a principle that requires physics to be quantum in origin.

    ↳ hep-thhep-phquant-phSciPost Phys.(2026)·15 citations
20. 20*

    The Glow of Axion Quark Nugget Dark Matter: (III) The Mysteries of the Milky Way UV Background

    Michael Sekatchev🇨🇦 · Xunyu Liang🇨🇦 · Fereshteh Majidi🇨🇦 · Ben Scully🇨🇦 · Ludovic Van Waerbeke🇨🇦 · Ariel Zhitnitsky🇨🇦

    Axion quark nuggets (AQNs) are hypothetical objects with nuclear density that would have formed during the quark-hadron transition and could make up most of the dark matter today. These objects have a mass greater than a few grams and are sub-micrometer in size. They would also help explain the matter-antimatter asymmetry and the similarity between visible and dark components of the universe, i.e. ${\Omega }_{\text{DM}}\sim {\Omega }_{\text{visible}}$. These composite objects behave as cold dark matter, interacting with ordinary matter and producing pervasive electromagnetic radiation. This work aims to calculate the FUV electromagnetic signature in a 1 kpc region surrounding the solar system, resulting from the interaction between antimatter AQNs and baryons. To this end, we use the high-resolution hydrodynamic simulation of the Milky Way, FIRE-2 Latter suite, to select solar system-like regions. From the simulated gas and dark matter distributions in these regions, we calculate the FUV background radiation generated by the AQN model. We find that the results are consistent with the FUV excess recently confirmed by the Alice spectrograph aboard New Horizons, which corroborated the FUV excess initially discovered by GALEX a decade ago. We also discuss the potential cosmological implications of our work, which suggest the existence of a new source of FUV radiation in galaxies, linked to the interaction between dark matter and baryons.

    ↳ astro-ph.COastro-ph.GAastro-ph.HEhep-phJCAP(2026)·7 citations
21. 21*

    Minimal Magnetogenesis: The Role of Inflationary Perturbations and ALPs, and Its Gravitational Wave Signatures

    Subhasis Maiti🇮🇳 · Debaprasad Maity🇮🇳 · Rohan Srikanth🇩🇪

    Any attempt to understand the ubiquitous nature of the magnetic field in the present universe seems to lead us towards its primordial origin. For large-scale magnetic fields, however, their strength and length scale may not necessarily originate from a singular primordial mechanism, namely inflationary magnetogenesis, which has been a popular consideration in the literature. In this paper, we propose a minimal scenario wherein a large-scale magnetic field is generated from the inflationary perturbation without any non-conformal coupling. Due to their origin in the inflationary scalar spectrum, these primordial fields are inherently weak, with their strength suppressed by the small amplitude of scalar fluctuations. We then consider the coupling between this large-scale weak primordial magnetic field and a light axion of mass $<10^{-28}$ eV, which is assumed to be frozen in a misaligned state until the photon decoupling. After the decoupling, when the universe enters into a dark age, the light axion coherently oscillates. By appropriately tuning the axion-photon coupling parameter $\alpha$, we demonstrate that a large-scale magnetic field of sufficient strength can indeed be generated through tachyonic resonance. We further show that the produced magnetic field induces a unique spectrum with multiple peaks of secondary gravitational waves, which the upcoming CMB-S4 can probe through B-mode polarization. The strength can be sufficient enough to violate the PLANCK bound on tensor-to-scalar ratio $r\lesssim 0.036$. Such a violation leads to a constraint on $\alpha \lesssim 80$. With this limiting value of the coupling, we find that present-day magnetic field strength could be as high as $10^{-10}$ Gauss at Mpc scale, consistent with observation.

    ↳ astro-ph.COhep-phhep-thPRD(2025)·7 citations
22. 22*

    Angular structure of many-body correlations in atomic nuclei: From nuclear deformations to diffractive vector meson production in $\gamma A$ collisions

    Jean-Paul Blaizot🇫🇷 · Giuliano Giacalone🇨🇭

    There is growing evidence that high-energy scattering processes involving nuclei can offer unique insights into the many-body correlations present in nuclear ground states, in particular those of deformed nuclei. These processes involve, for instance, the collective anisotropic flows in heavy-ion collisions, or the diffractive production of vector mesons in photo-nuclear ($\gamma A$) interactions. In this paper, we use a classical approximation and simple analytical models in order to exhibit characteristic and universal features of ground-state correlation functions that result from the presence of a deformed intrinsic state. In the case of a small axial quadrupole deformation, we show that the random rotation of the intrinsic density of the nucleus leads to a specific quadrupole modulation of the lab-frame two-body density as a function of the relative azimuthal angle. As a phenomenological, albeit academic application, we analyze the diffractive production of vector mesons in high-energy $\gamma {+}^8$Be collisions. This demonstrates with the simplest deformed nucleus how the two-body correlations impact the $|t|$ dependence of the incoherent cross sections.

    ↳ nucl-thhep-exhep-phnucl-exEPJA(2025)·14 citations
23. 23*

    Compton Form Factor Extraction using Quantum Deep Neural Networks

    Brandon B. Le🇺🇸 · Dustin Keller🇺🇸

    We extract Compton form factors (CFFs) from deeply virtual Compton scattering measurements at the Thomas Jefferson National Accelerator Facility (JLab) using quantum-inspired deep neural networks (QDNNs). The analysis implements the twist-2 Belitsky-Kirchner-Müller formalism and employs a fitting strategy that emulates standard local fits. Using pseudodata, we benchmark QDNNs against classical deep neural networks (CDNNs) and find that QDNNs often deliver higher predictive accuracy and tighter uncertainties at comparable model complexity. Guided by these results, we introduce a quantitative selection metric that indicates when QDNNs or CDNNs are optimal for a given experimental fit. After obtaining local extractions from the JLab data, we perform a standard neural-network global CFF fit and compare with previous global analyses. The results support QDNNs as an efficient and complementary tool to CDNNs for CFF determination and for future multidimensional studies of parton distributions and hadronic structure.

    ↳ cs.LGhep-phnucl-thquant-phPRC(2026)·6 citations
24. 24*

    A diagrammatic approach to correlation functions in superfluids

    Alessia Biondi🇫🇷 · Maria Luisa Chiofalo🇮🇹 · Massimo Mannarelli🇮🇹 · Silvia Trabucco🇮🇹

    Renaud Parentani has given a vast contribution to the development of gravitational analogue models as tools to explore various important aspects of general relativity and of quantum field theory in curved space-time. In these systems, two-point correlation functions are of the utmost importance for the characterization of processes taking place close to the acoustic horizon. In the present paper, dedicated to him, we present a study of path integral methods that allow to determine two-point correlation functions by a perturbative expansion, in a way that -- beyond its generality -- is especially suited to analyze these processes. Our results apply to non-relativistic superfluids, realizable in terrestrial experiments, as well as to relativistic superfluids, relevant for compact stellar objects.

    ↳ cond-mat.quant-gashep-phComptes Rendus Physique(2025)·0 citations
25. 25*

    Electroweak form factors of baryons in dense nuclear matter

    G. Ramalho🇰🇷 · K. Tsushima🇧🇷 · Myung-Ki Cheoun🇰🇷

    There is evidence that the properties of hadrons are modified in a nuclear medium. Information about the medium modifications of the internal structure of hadrons is fundamental for the study of dense nuclear matter and high-energy processes, including heavy-ion and nucleus--nucleus collisions. At the moment, however, empirical information about medium modifications of hadrons is limited; therefore, theoretical studies are essential for progress in the field. In the present work, we review theoretical studies of the electromagnetic and axial form factors of octet baryons in symmetric nuclear matter. The calculations are based on a model that takes into account the degrees of freedom revealed in experimental studies of low and intermediate square transfer momentum $q^2=-Q^2$: valence quarks and meson cloud excitations of baryon cores. The formalism combines a covariant constituent quark model, developed for a free space (vacuum) with the quark--meson coupling model for extension to the nuclear medium. We conclude that the nuclear medium modifies the baryon properties differently according to the flavor content of the baryons and the medium density. The effects of the medium increase with density and are stronger (quenched or enhanced) for light baryons than for heavy baryons. In particular, the in-medium neutrino--nucleon and antineutrino--nucleon cross-sections are reduced compared to the values in free space. The proposed formalism can be extended to densities above the normal nuclear density and applied to neutrino--hyperon and antineutrino--hyperon scattering in dense nuclear matter.

    ↳ nucl-thhep-exhep-lathep-ph+1Symmetry(2025)·8 citations
26. 26*

    Compatibility of recent $\Xi$-nuclear bound state signals

    E. Friedman🇮🇱 · A. Gal🇮🇱

    J-PARC E05 reported recently a hint of a ${\Xi }^{-}-{}^{11}\mathrm{B}$ nuclear state in the ${}^{12}\mathrm{C}(K^{-},K^{+}){}_{\Xi }^{12}\mathrm{Be}$ spectrum, bound by $B_{{\Xi }^{-}}=8.9\pm 1.4{}_{-3.1}^{+3.8}$ MeV. Using a density-dependent $\Xi$-nuclear optical potential $V_{\mathrm{opt}}^{\Xi }(\rho )$ we explore to what extent a ${\Xi }_{1s}^{-}$ assignment of this nuclear state is compatible with ${\Xi }_{1s}^{-}$ and ${\Xi }_{1p}^{-}$ nuclear-state interpretations of ${\Xi }^{-}$ capture events in light emulsion-nuclei experiments. We find that the only acceptable ${\Xi }_{1s}^{-}$ assignment at present, barring an abnormally strong repulsive ${\rho }^2$ component of $V_{\mathrm{opt}}^{\Xi }(\rho )$, is that for the ${\Xi }^{-}-{}^{11}\mathrm{B}$ signal. This finding supports reassigning ${\Xi }^{-}$ capture events in ${}^{14}$N, originally assigned as ${\Xi }_{1s}^{-}-{}^{14}\mathrm{N}$ nuclear states, to ${\Xi }_{1p}^0-{}^{14}\mathrm{C}$ nuclear states. The depth of $V_{\mathrm{opt}}^{\Xi }(\rho )$ at nuclear-matter density ${\rho }_0=0.17$ fm${}^{-3}$ is then $-V_{\mathrm{opt}}^{\Xi }({\rho }_0)\sim 21$ MeV.

    ↳ nucl-thhep-phnucl-exPLB(2025)·7 citations
27. 27*

    Modeling Tidal Disruptions with Dynamical Tides

    Zihan Zhou🇺🇸 · Giovanni Maria Tomaselli🇺🇸 · Irvin Martínez-Rodríguez🇿🇦 · Jingping Li🇺🇸

    Tidal disruption events (TDEs) occur when stars pass close enough to supermassive black holes to be torn apart by tidal forces. Traditionally, these events are studied with computationally intensive hydrodynamical simulations. In this paper, we present a fast, physically motivated two-stage model for TDEs. In the first stage, we model the star's tidal deformation using linear stellar perturbation theory, treating the star as a collection of driven harmonic oscillators. When the tidal energy exceeds a fraction $\gamma$ of the star's gravitational binding energy (with $\gamma \sim \mathcal{O}(1)$), we transition to the second stage, where we model the disrupted material as free particles. The parameter $\gamma$ is determined with a one-time calibration to the critical impact parameter obtained in hydrodynamical simulations. This method enables fast computation of the energy distribution $\mathrm{d}M/\mathrm{d}E$ and fallback rate $\mathrm{d}M/\mathrm{d}T$, while offering physical insight into the disruption process. We apply our model to MESA-generated profiles of middle-age main-sequence stars. Our code is available on GitHub.

    ↳ astro-ph.HEastro-ph.GAastro-ph.SRgr-qc+2ApJ(2025)·4 citations
28. 28*

    RGUP Corrections to Scalar and Fermionic Fields

    Gaurav Bhandari🇮🇳 · S. D. Pathak🇮🇳 · Vikash Kumar Ojha🇮🇳

    We investigate the Relativistic Generalized Uncertainty Principle (RGUP) effects on scalar and fermionic fields using the Stetsko-Tkachuk approximation. Modified equations of motion, Hamiltonians, and stress-energy tensors are derived in Minkowski spacetime, incorporating quantum gravitational corrections that ensure a minimal observable length and revert to standard dynamics when corrections are absent. For fermionic fields in curved spacetime, spin connections maintain gravitational consistency. This framework, applicable to high-energy physics, black hole thermodynamics, and cosmology, integrates quantum gravity into relativistic field theories.

    ↳ gr-qchep-phhep-thEur.Phys.J.Plus(2025)·4 citations
29. 29*

    Sub-Horizon Amplification of Curvature Perturbations: A New Route to Primordial Black Holes and Gravitational Waves

    Debottam Nandi (CCSP, SGT University)🇮🇳 · Rohan Roy🇮🇳 · Simran Yadav🇮🇳 · Arnab Sarkar🇮🇳

    The enhanced primordial scalar power spectrum is a widely studied mechanism for generating primordial gravitational waves (PGWs), also referred to as scalar-induced gravitational waves (SIGWs). This process also plays a pivotal role in facilitating the formation of primordial black holes (PBHs). Traditionally, the ultra slow-roll (USR) mechanism has been the predominant approach used in the early universe. In this framework, the second slow-roll parameter ${ϵ}_2$, is typically set to $-6$ or lower for a brief period -- marking a significant departure from the standard slow-roll condition where ${ϵ}_2\simeq 0$. Such conditions often emerge in models with inflection points or localized features, such as bumps in the potential. In this paper, we challenge the conventional assumption that ${ϵ}_2\lesssim -6$ is a prerequisite for substantial amplification of the scalar power spectrum. We demonstrate that any negative value of the second slow-roll parameter can indeed enhance the scalar power spectrum through sub-horizon growth, establishing this as a necessary and sufficient condition for amplification. Consequently, this mechanism facilitates the generation of both PGWs and PBHs. To illustrate this, we examine a standard scenario where a brief USR phase is embedded between two slow-roll (SR) phases. By systematically varying ${ϵ}_2$ values from $-1$ to $-10$ in the USR region, we investigate the amplification of the power spectrum and its implications for PGWs and PBHs production, particularly in the context of ongoing and future cosmological missions.

    ↳ astro-ph.COgr-qchep-phhep-th3 citations
30. 30*

    Increase of $n_s$ in regularized pole inflation & Einstein-Cartan gravity

    Minxi He🇰🇷 · Muzi Hong🇯🇵 · Kyohei Mukaida🇯🇵

    We show that the regularization of the second order pole in the pole inflation can induce the increase of $n_s$, which may be important after the latest data release of cosmic microwave background (CMB) observation by Atacama Cosmology Telescope (ACT). Pole inflation is known to provide a unified description of attractor models that they can generate a flat plateau for inflation given a general potential. Recent ACT observation suggests that the constraint on the scalar spectral index $n_s$ at CMB scale may be shifted to a larger value than the predictions in the Starobinsky model, the Higgs inflation, and the $\alpha$-attractor model, which motivates us to consider the modification of the pole inflation. We find that if we regularize the second order pole in the kinetic term such that the kinetic term becomes regular for all field range, we can generally increase $n_s$ because the potential in the large field regime will be lifted. We have explicitly demonstrated that this type of regularized pole inflation can naturally arise from the Einstein-Cartan formalism, and the inflationary predictions are consistent with the latest ACT data without spoiling the success of the $\alpha$-attractor models.

    ↳ astro-ph.COhep-phJCAP(2025)·58 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.