Thu·Nov 14, 2024Thursday·November 14, 2024

1. 01*

   Impact of background field localization on vacuum polarization effects

   Carl Marmier🇫🇷 · Nico Seegert🇩🇪 · Felix Karbstein🇩🇪

   We aim at insights about how localization of the background field impacts nonlinear quantum vacuum signatures probed by photons in purely magnetic, electric and crossed fields. The starting point of our study are the one-loop results for the Heisenberg-Euler effective Lagrangian and the photon polarization tensor in quantum electrodynamics (QED) evaluated in a uniform constant electromagnetic field. As is well known and often employed, especially in the weak-field limit, within certain restrictions these results also allow for the reliable analysis of vacuum polarization effects in slowly varying background fields. Here, our main interest is in manifestly non-perturbative effects. To this end, we make use of the fact that for the particular case of background field inhomogeneities of Lorentzian shape with $0\le d\le 3$ inhomogeneous directions analytical insights are possible. We study the scaling of conventional nonlinear QED signatures, such as probe-photon polarization flip and probe-photon induced electron-positron pair production, with relevant parameters. Special attention is put on the $d$ dependence of the considered effects.

   hep-phhep-thquant-phPRD(2025)·5 citations
2. 02*

   Pion Nuclear Fragmentation Functions Revisited

   Matias Doradau🇦🇷 · Ramiro Tomas Martinez🇦🇷 · Rodolfo Sassot🇦🇷 · Marco Stratmann🇩🇪

   We revisit the notion of nuclear parton-to-pion fragmentation functions at next-to-leading order accuracy as an effective description of hadroproduction in nuclear environments such as in semi-inclusive lepton-nucleus deep-inelastic scattering and in single inclusive proton-nucleus collisions. We assess their viability in the face of very precise data collected for the latter at the CERN-LHC over the past decade as well as recent measurements of the former carried out by the CLAS experiment at JLab.

   hep-phhep-exnucl-exPRD(2025)·6 citations
3. 03*

   Spin dynamics with realistic hydrodynamic background for relativistic heavy-ion collisions

   Sushant K. Singh🇮🇹 · Radoslaw Ryblewski🇵🇱 · Wojciech Florkowski🇵🇱

   The equations of perfect spin hydrodynamics are solved for the first time using a realistic (3+1)-dimensional hydrodynamic background, calibrated to reproduce a comprehensive set of hadronic observables, including rapidity distributions, transverse momentum spectra, and elliptic flow coefficients for Au+Au collisions at the beam energy of $\sqrt{s_{\mathrm{NN}}}=200$ GeV. The spin dynamics is governed by the conservation of the spin tensor, describing spin-$\frac{1}{2}$ particles, with particle mass in the spin tensor treated as an effective parameter. We investigate several scenarios, varying both the effective mass and the initial evolution time for the spin polarization tensor. The model predictions are then compared with experimental measurements of global and longitudinal spin polarization of Lambda hyperons. Our results indicate that a successful description of the data requires a delayed initial evolution time for the perfect spin hydrodynamics of about 4 fm/$c$ (in contrast to the standard initial time of 1 fm/$c$ used for the hydrodynamic background). This delay marks a transition from the phase where spin-orbit interaction is significant to the regime where spin-conserving processes dominate. Our findings suggest that the spin-orbit dissipative interaction plays a significant role only in the very early stages of the system's evolution.

   hep-phnucl-thPRC(2025)·32 citations
4. 04*

   Collisional Approach for Open Neutrino Systems

   W.L.Ribeiro🇧🇷 · C.A.Moura🇧🇷

   We develop a collisional framework for neutrino propagation within open quantum systems, termed the \emph{Collisional Approach for Open Neutrino Systems} (CAONS). A Born-Markov equation is derived, linking decoherence, dissipation, decay rates, and scattering cross sections. Perturbation theory is not required and the resultant master equation is applied to visible and invisible neutrino decays and propagation through a stationary medium. Comparing with previous studies on neutrino decoherence, we show that current bounds on decoherence parameters can significantly tighten constraints on neutrino couplings with dark-matter. Lastly, we establish connections between CAONS and non-Hermitian Hamiltonian approaches.

   hep-ph3 citations
5. 05*

   Hypernuclei production with a modified coalescence model in BUU transport calculations

   Gabor Balassa🇰🇷 · Gyorgy Wolf🇭🇺

   In this paper, the usual momentum- and coordinate-space distance criteria for creating nuclear clusters in transport simulations are addressed by using a dynamical, covariant description in an off-shell Boltzmann-Uehling-Uhlenbeck transport approach. The free parameter of this clustering scheme is the cluster formation time, which is fitted through the FOPI data of low energy charged cluster multiplicities in Au+Au collisions at 150 A MeV and 400 A MeV incident energies. The coalescence model is used to estimate the yields of the 3H(Lambda), 5H(2Lambda), 6He(2Lambda) single and double strange hypernuclei in central Au+Au collisions between 2, and 20 A GeV incident energies, giving comparable results to estimations from other methods.

   hep-phnucl-thEPJA(2023)·3 citations
6. 06*

   Translating current ALP photon coupling strength bounds to the Randall-Sundrum model

   Shihabul Haque🇮🇳 · Sourov Roy🇮🇳 · Soumitra SenGupta🇮🇳

   In this article, we look at the current bounds on the coupling strength of axion-like particles (ALPs) with two photons in the context of the Randall-Sundrum (RS) model. We relate the coupling strength to the compactification radius that governs the size of the extra dimension in the RS warped geometry model and show how the current bounds on the ALP can be used to derive appropriate constraints on the size of the extra fifth dimension in the RS model. We show that the resulting constraints fail to resolve the gauge hierarchy problem for light/ultralight ALPs and require a massive ALP of at least $m_a\gtrsim 0.1$ [GeV] to be relevant in the context of the hierarchy problem when the gauge field is in the bulk.

   hep-phastro-ph.HEgr-qchep-thPhys.Dark Univ.(2026)·2 citations
7. 07*

   Odyssey of the elusive ${\Theta }^{+}$

   Michal Praszalowicz🇵🇱

   ${\Theta }^{+}$ is a putative light pentaquark state of positive parity with minimal quark content $(uudd\bar{s})$. It naturally emerges in chiral models for baryons, but experimental evidence is uncertain. We review the theoretical foundations of chiral models and their phenomenological applications to exotic states. In particular, we discuss in detail the pentaquark widths with special emphasis on the cancellations occurring in the decay operator. We also discuss some experiments, mainly those whose positive evidence of ${\text{mit}\Theta }^{+}$ persists to this day. This review is dedicated to Dmitry Diakonov, Victor Petrov, and Maxim Polyakov and their contribution to the ${\text{mit}\Theta }^{+}$ story.

   hep-phActa Phys.Polon.B(2025)·8 citations
8. 08*

   Upper limit on dark matter mass in the inert doublet model

   Wararat Treesukrat🇹🇭 · Kem Pumsa-ard🇹🇭 · Nopmanee Supanam🇹🇭 · Patipan Uttayarat🇹🇭

   We study the upper limit on dark matter mass in the context of the inert double model. We derive analytic expression for the upper bound as a function of the mass squared differences between dark matter and other new particles. We find that the upper limit varies between 20$-$80 TeV depending on the mass squared splitting.

   hep-phPRD(2024)·1 citation
9. 09*

   The time evolution of light nuclei cumulants and ratios with a first-order phase transition in the UrQMD transport model

   Thiranat Bumnedpan🇩🇪 · Jan Steinheimer🇩🇪 · Tom Reichert🇩🇪 · Christoph Herold🇹🇭 · Ayut Limphirat🇹🇭 · Marcus Bleicher🇩🇪

   The UrQMD model with a density dependent equation of state, including a first-order phase transition, is used to study the time dependence of baryon number and proton number susceptibilities up to third order in heavy ion reactions of $E_{\mathrm{lab}}=2-3A$ GeV. A significant deviation from the Gaussian fluctuations of the baryon number fluctuation in coordinate space is observed. The proton number fluctuations are always suppressed as they constitute only a small fraction of the total baryon number during the dense phase of the collision. It is found that the only measurable, but small, signal would be an enhancement of the third order (or higher) proton cumulant in a finite rapidity window $\Delta y$ that is larger than one unit of rapidity. In addition, it is found that the coordinate fluctuations will lead to an enhancement of cluster production due to the correlations in coordinate space. However, this enhancement is small and mainly occurs during the dense part of the collision before the system actually freezes out.

   hep-phnucl-thPRC(2025)·2 citations
10. 10*

    Revisiting $B\to K^{\ast }\pi$ and $B\to K\rho$ decays using the modified perturbative QCD approach

    Ru-Xuan Wang🇨🇳 · Mao-Zhi Yang🇨🇳

    We revisit $B\to K^{\ast }\pi$ and $B\to K\rho$ decay processes using the modified perturbative QCD approach, which is developed based on the perturbative QCD approach with a few improvements. A critical infrared cutoff scale ${\mu }_c$ is introduced to separate hard and soft contributions in the decay process. Hard contributions with scale $\mu$ larger than ${\mu }_c$ are calculated with perturbative QCD, and soft contributions with $\mu <{\mu }_c$ are described in terms of soft transition and production form factors. In addition, color-octet contributions are considered phenomenologically. The branching fractions and $CP$ violations of $B\to K^{\ast }\pi$, $K\rho$ decays are calculated. With appropriate parameter inputs, the theoretical results can be in good agreement with experimental data.

    hep-phEPJC(2025)·5 citations
11. 11*

    More Scalings from Cosmic Strings

    Heejoo Kim🇰🇷 · Minho Son🇰🇷

    We analyze all individual cosmic strings of various lengths in a large ensemble of the global cosmic string networks in the post-inflationary scenario, obtained from numerical simulations on a discrete lattice with $N^3=4096^3$. A strong evidence for a logarithmically growing spectral index of the string power spectrum during the evolution is newly reported as our main result. The logarithmic scaling is checked against two different approaches for generating initial random field configurations, namely fat-string type and thermal phase transition. We derive the analytic relation between two power spectra of cosmic strings and axions which should be valid under some assumptions, and the validity of those assumptions is discussed. We argue that our analytic result strongly supports the correlated spectra of cosmic strings and axions. Additionally, we initiate the statistical analysis of the causal dynamics of the cosmic strings.

    hep-phJHEP(2025)·18 citations
12. 12*

    Modified Models for Neutrino Masses and Mixings

    Arak M. Mathai🇨🇦 · Hans J. Haubold🇦🇹

    The neutrino sector of the seesaw-modified Standard Model is investigated under the anarchy principle. The anarchy principle leading to the seesaw ensemble is studied analytically with tools of random matrix theory. The probability density function is obtained.

    hep-phastro-ph.SRJ.Math.Phys.(2025)·1 citation
13. 13*

    Mass Spectrum, Radii, and Radiative Decay Widths of Toponium

    Nosheen Akbar🇵🇰 · Ishrat Asghar🇵🇰 · Zaki Ahmad🇵🇰

    In this work, radial Schrodinger equation with a non-relativistic quark potential model (NRQPM) is solved numerically by employing the shooting method. Calculated numerical wave functions (or solutions) are used to compute the masses, root mean square (RMS) radii, $E1$ and $M1$ radiative transitions, and branching ratios of $S,P,D$ and $F$ states of toponium mesons ($t\overline{t}$). Calculated results are compared with recently available theoretical data. This work will be helpful for experimentalists in gaining a deeper understanding of toponium states.

    hep-phAdv.High Energy Phys.(2026)·9 citations
14. 14*

    Nonlinear Breit-Wheeler pair production using polarized photons from inverse Compton scattering

    Daniel Seipt🇩🇪 · Mathias Samuelsson🇸🇪 · Tom Blackburn🇸🇪

    Observing multiphoton electron-positron pair production (the nonlinear Breit-Wheeler process) requires high-energy $\gamma$ rays to interact with strong electromagnetic fields. In order for these observations to be as precise as possible, the $\gamma$ rays would ideally be both mono-energetic and highly polarized. Here we perform Monte Carlo simulations of an experimental configuration that accomplishes this in two stages. First, a multi-GeV electron beam interacts with a moderately intense laser pulse to produce a bright, highly polarized beam of $\gamma$ rays by inverse Compton scattering. Second, after removing the primary electrons, these $\gamma$ rays collide with another, more intense, laser pulse in order to produce pairs. We show that it is possible to measure the $\gamma$-ray polarization dependence of the nonlinear Breit-Wheeler process in near-term experiments, using a 100-TW class laser and currently available electron beams. Furthermore, it would also be possible to observe harmonic structure and the perturbative-to-nonperturbative transition if such a laser were colocated with a future linear collider.

    hep-phphysics.plasm-phPlasma Phys.Control.Fusion(2025)·9 citations
15. 15*

    Evolution of Effective Temperature, Kinetic Freeze-out Temperature and transverse flow velocity in pp Collision

    Murad Badshah🇵🇰 · Muhammad Ajaz🇵🇰 · Muhammad Waqas🇨🇳 · Hannan Younis🇵🇰

    This article focuses on the study of strange hadrons at 0.2 TeV centre of mass energy, recorded by STAR at RHIC, and at 0.9 TeV, 5.02 TeV and 7 TeV, recorded by CMS at LHC, in pp collision in the rapidity range from 0 to 2. The transverse momentum distributions of these strange particles have been processed using two statistical models, the Tsallis and the modified Hagedorn model. Both models fit the experimental data well. We extracted different freezeout parameters from the fit procedure using the abovementioned functions. We found that with increasing the collision energy, the effective temperature (T), in the case of the Tsallis model, and kinetic/thermal freeze-out temperature (T0) and transverse flow velocity, in the case of the modified Hagedorn model, increase because of greater energy transfer among the participants at higher colliding energies. Both T and T0 are observed to increase with the increase in the rest masses of the outgoing particles revealing the multi-freeze-out scenario. Furthermore, the multiplicity parameter (N0) decreases with the increase in the particle mass, confirming the mass differential freeze-out scenario. An inverse relationship between the non-extensivity parameter (q) and the masses of the produced particles has been noticed. Similarly, an inverse correlation between q and T has been found. For lighter particles, smaller T and greater q mean that they decouple from the system later and attain equilibrium slowly compared to heavier ones. In addition, a positive correlation between transverse flow velocity and T0 is noticed, which agrees with the literature.

    hep-phPhys.Scripta(2023)·8 citations
16. 16*

    Search for the $\gamma Z$ decay mode of heavy photophobic axion-like particles at the LHC

    Zilong Ding🇨🇳 · Ying-nan Mao🇨🇳 · Kechen Wang🇨🇳

    We assume the coupling of Axion-like particle (ALP) to diphoton $g_{a\gamma \gamma }\sim 0$ and accomplish detailed analyses for the $\gamma Z$ decay mode of such heavy photophobic ALPs at the high luminosity-Large Hadron Collider (HL-LHC). ALPs are produced with two jets via both the $s$-channel vector boson exchange and vector boson fusion processes, with the signal process $pp\to jja(\to \gamma Z(\to {\ell }^{+}{\ell }^{-}))$ for $\ell =e,\mu$. Signal and background events are simulated at the detector-level. Preselection criteria target events with one photon, two oppositely charged electrons or muons, and two non-$b$-tagged jets. The ALP mass is reconstructed, and kinematic observables are input into a machine learning-based multivariate analysis for optimal background rejection. Discover sensitivities on the ALP's coupling to di-$W$ boson, $g_{aWW}$, are presented in the mass range from 100 to 4000 GeV at center-of-mass energy $\sqrt{s}=14$ TeV and integrated luminosity $\mathcal{L}=$ 3 ab${}^{-1}$ and 140 fb${}^{-1}$. Sensitivities on the production cross section $\sigma (pp\to jja)$ times the branching ratio Br$(a\to \gamma Z)$ are also presented.

    hep-phJHEP(2025)·10 citations
17. 17*

    Systematic analysis of the pp collisions at LHC energies with Tsallis function

    Murad Badshah🇵🇰 · Muhammad Waqas🇨🇳 · Ahmed M. Khubrani🇸🇦 · Muhammad Ajaz🇵🇰

    This work focuses on the study of identified hadrons and strange hadrons, recorded by CMS, and light nuclei and their anti-nuclei, recorded by ALICE, at 0.9 TeV, 2.76 TeV, 7 TeV and 13 TeV centre of mass energies in pp collision at mid rapidities. The transverse momentum distributions of these particles are analyzed using the Tsallis model, which fits the experimental data very well. Several important parameters for studying the characteristics of the medium produced during such collisions are extracted. The effective temperature (T) increases monotonically with increasing particle mass and also with increasing collision energy. The non-extensivity parameter (q) decreases with the mass of the particle. For heavier particles, greater T and smaller q mean that they decouple early from the system and attain equilibrium quickly compared to lighter ones. Furthermore, with an increase in collision energy, the multiplicity parameter N0 increases.

    hep-phEPL(2023)·16 citations
18. 18*

    Chiral Gravitational Wave Background from Audible Axion via Nieh-Yan Term

    Baoyu Xu🇨🇳 · Keyi Ding🇳🇱 · Hong Su🇨🇳 · Ju Chen🇨🇳 · Yun-Long Zhang🇨🇳

    Axions and axion-like particles can be probed through gravitational waves indirectly, often referred to as "audible axions". The usual concept of audible axion relies on the coupling between the axions and the gauge fields. Here we consider an axion-like mechanism with coupling to the Nieh-Yan term. This interaction leads to the direct and efficient production of gravitational waves during the radiation-dominated era, originating from the tachyonic instability of the gravitational perturbations with the Nieh-Yan term. We calculate the energy spectral density of the chiral gravitational wave background and the comoving energy density of axion-like fields. Based on the numerical results, we explore the parameter space of axion masses and decay constants for detectable gravitational wave signals, either in pulsar timing arrays or space-based gravitational wave detections.

    hep-phastro-ph.COgr-qcPhys.Dark Univ.(2025)·10 citations
19. 19*

    Perturbative Unitarity Violation in Radiative Capture Transitions to Dark Matter Bound States

    Martin Beneke🇩🇪 · Tobias Binder🇩🇪 · Lorenzo de Ros🇩🇪 · Mathias Garny🇩🇪 · Stefan Lederer🇩🇪

    We investigate the formation of bound states of non-relativistic dark matter particles subject to long-range interactions through radiative capture. The initial scattering and final bound states are described by Coulomb potentials with different strengths, as relevant for non-abelian gauge interactions or theories featuring charged scalars. For bound states with generic quantum numbers $n$ and $\ell$, we provide closed-form expressions for the bound-state formation (BSF) cross sections of monopole, dipole and quadrupole transitions, and of arbitrary multipole order when $\ell =n-1$. This allows us to investigate in detail a strong enhancement of BSF that occurs for initial states in a repulsive potential. For $\ell =n-1\gg 1$, we show that the BSF cross section for each single bound state violates the perturbative unitarity bound in the vicinity of a certain critical initial velocity, and provide an interpretation in terms of a smooth matching of classical trajectories. When summing the BSF cross section over all possible bound states in the final state, this leads to a unitarity violation below a certain velocity, but within the validity range of the weakly coupled non-relativistic description. We identify an effectively strong interaction as the origin of this unitarity violation, which is caused by an "anomalously" large overlap of scattering and bound-state wave functions in Coulomb potentials of different strength.

    hep-phastro-ph.COJHEP(2025)·11 citations
20. 20*

    Tree-level soft emission for two pairs of quarks

    Xinguang Chen🇨🇳 · Zhengwen Liu🇩🇰

    We compute the tree-level current for the emission of two soft quark-antiquark pairs in a hard scattering. We also compute the square of this current and discuss the resulting color correlations, featuring dipole correlations and three-parton correlations. This object is essential for analyzing the infrared singularities at next-to-next-to-next-to-next-to-leading-order (N4LO) predictions in perturbative QCD.

    hep-phhep-thJHEP(2025)·7 citations
21. 21*

    Next-to-leading order QCD corrections to $Z\to q\bar{q}\gamma$, $q\bar{q}\gamma \gamma$

    Pankaj Agrawal🇮🇳 · Subhadip Bisal🇮🇳 · Biswajit Das🇮🇳 · Debottam Das🇮🇳

    We consider the rare decay channels of the $Z$ boson: $Z\to \text{two}\text{jets}+\gamma$ and $Z\to \text{two}\text{jets}+2\gamma$. To obtain the widths and distributions for these processes, we compute the effect of NLO QCD corrections to the processes $Z\to q\bar{q}+\gamma$ and $Z\to q\bar{q}+2\gamma$. We find that these corrections reduce the widths of these processes by about $6.03\%$ and $12.39\%$, respectively. The reduction in the partial widths is larger at the jet level. These NLO-improved decay observables may be tested in future runs of the LHC or at future $e^{+}{e}^{-}$ colliders.

    hep-ph0 citations
22. 22*

    Perturbative gravitational wave predictions for the real-scalar extended Standard Model

    Oliver Gould🇬🇧 · Paul Saffin🇬🇧

    We perform a state-of-the-art study of the cosmological phase transitions of the real-scalar extended Standard Model. We carry out a broad scan of the parameter space of this model at next-to-next-to-leading order in powers of couplings. We use effective field theory to account for the necessary higher-order resummations, and to construct consistent real and gauge-invariant gravitational wave predictions. Our results provide a comprehensive account of the convergence of perturbative predictions for the gravitational wave signals in this model. For the majority of the parameter points in our study, we observe apparent convergence. While leading and next-to-leading order predictions of the gravitational wave amplitude typically suffer from relative errors between $10$ and $10^4$, at next-to-next-to-leading order the typical relative errors are reduced to between $0.5$ and $50$. Nevertheless, for those parameter points predicting the largest signals, potentially observable by future gravitational wave observatories, the validity of the perturbative expansion is in doubt.

    hep-phastro-ph.COhep-thJHEP(2025)·27 citations
23. 23*

    NLO SMEFT Electroweak Corrections to Higgs Decays to 4 Leptons in the Narrow Width Approximation

    Sally Dawson🇺🇸 · Matthew Forslund🇺🇸 · Pier Paolo Giardino🇪🇸

    Some of the most precise measurements of Higgs boson couplings are from the Higgs decays to 4 leptons, where deviations from the Standard Model predictions can be quantified in the framework of the Standard Model Effective Field Theory (SMEFT). In this work, we present a complete next-to-leading order (NLO) SMEFT electroweak calculation of the rate for $H\to {\ell }^{+}{\ell }^{-}Z$ which we combine with the NLO SMEFT result for $Z\to {\ell }^{+}{\ell }^{-}$ to obtain the NLO rate for the $H\to$ 4 lepton process in the narrow width approximation. The NLO calculation provides sensitivity to a wide range of SMEFT operators that do not contribute to the rate at lowest order and demonstrates the importance of including correlations between the effects of different operators when extracting limits on SMEFT parameters. We show that the extraction of the Higgs tri-linear coupling from the decay $H\to {\ell }^{+}{\ell }^{-}Z,Z\to {\ell }^{+}{\ell }^{-}$ in the narrow width approximation strongly depends on the contributions of other operators that first occur at NLO.

    hep-phPRD(2025)·18 citations
24. 24*

    Investigating vector-like leptons decaying into an electron and missing transverse energy in e${}^{+}$ e${}^{-}$ collisions with $\sqrt{s}=500$ GeV at the ILC

    Y.Mahmoud · J.Kawamura · M.T. Hussein🇪🇬 · H.Abdallah · S.Elgammal

    This analysis focuses on probing the lepton portal dark matter using Monte Carlo simulated samples from electron-positron collisions at the International Linear Collider (ILC) of 500 GeV center of mass energy with an integrated luminosity of 1000 fb${}^{-1}$. The study examines a benchmark scenario where the dark matter is a scalar particle produced as a daughter particle of the vector-like lepton. The signal topology consists of missing transverse energy and dilepton. If no new physics is discovered,the study sets 95\% confidence level exclusion limits on the mass of vector-like leptons.

    ↳ hep-exhep-phJHEP(2025)·7 citations
25. 25*

    Embedded structure in quantum theory, functional operator and multiverse

    Yoshiharu Kawamura🇯🇵

    We explore a wider theoretical framework that has quantum field theory built-in, taking the fact that quantum mechanics is reconstructed from quantum field theory as a hint. We formulate a quantum theory with an embedded structure by introducing functional operators, and we find that it could describe the level II multiverse. Topics related to a beginning of the universe such as an inflation, the third quantization and the landscape are discussed in our formulation.

    ↳ hep-thgr-qchep-phquant-phPTEP(2025)·0 citations
26. 26*

    Inflationary constraints on the moduli-dependent species scale in modular invariant theories

    Shuntaro Aoki🇰🇷 · Hajime Otsuka🇯🇵

    We demonstrate that a broad class of modular inflation models predicts the emergence of new physics within an energy range of approximately \( 10^{15} \, \mathrm{GeV} \) to \( 10^{17} \, \mathrm{GeV} \). This prediction arises by comparing the moduli-dependent species scale with observational constraints on inflation. Specifically, we illustrate this within the context of \( SL(2, \mathbb{Z}) \)-modular inflation models by re-expressing inflationary observables in terms of the species scale. We further discuss the implications of this approach for generic Calabi-Yau threefolds.

    ↳ hep-thastro-ph.COgr-qchep-phPRD(2025)·8 citations
27. 27*

    Quasi-steady evolution of fast neutrino-flavor conversions

    Jiabao Liu🇯🇵 · Hiroki Nagakura🇯🇵 · Masamichi Zaizen🇯🇵 · Lucas Johns🇺🇸 · Ryuichiro Akaho🇯🇵 · Shoichi Yamada🇯🇵

    In astrophysical environments such as core-collapse supernovae (CCSNe) and binary neutron star mergers (BNSMs), neutrinos potentially experience substantial flavor mixing due to the refractive effects of neutrino self-interactions. Determining the survival probability of neutrinos in asymptotic states is paramount to incorporating flavor conversions' effects in the theoretical modeling of CCSN and BNSM. Some phenomenological schemes have shown good performance in approximating asymptotic states of fast neutrino-flavor conversions (FFCs), known as one of the collective neutrino oscillation modes induced by neutrino self-interactions. However, a recent study showed that they would yield qualitatively different asymptotic states of FFC if the neutrino number is forced to evolve. It is not yet fully understood why the canonical phenomenological models fail to predict asymptotic states. In this paper, we perform detailed investigations through numerical simulations and then provide an intuitive explanation with a quasi-homogeneous analysis. Based on the analysis, we propose a new phenomenological model, in which the quasi-steady evolution of FFCs is analytically determined. The model also allows us to express the convolution term of spatial wave number as a concise form, which corresponds to useful information on analyses for the non-linear feedback from small-scale flavor conversions to large-scale ones. Our model yields excellent agreement with numerical simulations, which lends support to our interpretation.

    ↳ astro-ph.HEhep-phPRD(2025)·17 citations
28. 28*

    Higher partial waves in femtoscopy

    Koichi Murase🇯🇵 · Tetsuo Hyodo🇯🇵

    Femtoscopy is recently gaining more attention as a new approach complementary to scattering experiments for constraining hadron-hadron interactions. We discuss the effect of higher partial waves on the two-particle correlation function, which has been neglected in traditional formulae used in the femtoscopy analyses. We consider the partial-wave expansion of the wave function in the Koonin-Pratt formula to give the correction to the correlation function by a sum of the contributions from each partial wave. We also generalize the Lednicky-Lyuboshitz formula, which was originally derived for the s-wave interaction, for higher partial waves. We find a compact representation of the generalized Lednicky-Lyuboshitz formula given by the backward scattering amplitude $f(\theta =\pi )$ and the Fourier-Laplace transform of the relative source function, which gives an insight into the structure of the Lednicky-Lyuboshitz formula and its relation to the optical theorem. We numerically demonstrate the significance of higher partial waves with resonances using the square potential well. Also, the generalized Lednicky-Lyuboshitz formula turned out to be broken for higher partial waves, which suggests the importance of the centrifugal force for the higher partial waves.

    ↳ nucl-thhep-phJ.Subatomic Part.Cosmol.(2025)·7 citations
29. 29*

    Constraining Axion-Like Particles from observations of AGN B2 2234+28A and 3C 454.3

    Yu-Chong Chen🇬🇧 · Siyu Chen🇨🇳 · Wei-Cong Huang🇨🇳 · Qing Yang🇨🇳 · Hong-Hao Zhang🇨🇳

    Axion-photon oscillation effect provides a possible explanation for the presence of very-high-energy (VHE) $\gamma$-ray signals from distant sources. In this work, we propose a model-dependent method to select possible sources that may give sufficient constraints on the axion parameters. We investigate such effect in the spectra of active galactic nuclei (AGN) B2 2234+28A and 3C 454.3 based on data obtained from Fermi Large Area Telescope (Fermi-LAT) and MAGIC U.L. We utilize the Markov Chain Monte Carlo method to fit the axion parameters, yielding a result of $g_{a\gamma }=3.05_{-0.31}^{+0.51}\times 10^{-11}$ GeV${}^{-1}$ for the axion-photon coupling strength and $m_a=5.25_{-2.65}^{+2.35}\times 10^{-8}$ eV for the axion mass. We also perform 95\% confidence level (CL) constraints to set an upper limit for $g_{a\gamma }$.

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2025)·2 citations
30. 30*

    Revisiting holographic dark energy after DESI 2024

    Tian-Nuo Li🇺🇸 · Yun-He Li🇺🇸 · Guo-Hong Du🇺🇸 · Peng-Ju Wu🇨🇳 · Lu Feng🇨🇳 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    New insights from the Dark Energy Spectroscopic Instrument (DESI) 2024 baryon acoustic oscillations (BAO) data, in conjunction with cosmic microwave background (CMB) and Type Ia supernova (SN) data, suggest that dark energy may not be a cosmological constant. In this work, we investigate the cosmological implications of holographic dark energy (HDE) and interacting holographic dark energy (IHDE) models, utilizing CMB, DESI BAO, and SN data. By considering the combined DESI BAO and SN data, we determine that in the IHDE model, the parameter $c>1$ and the dark-energy equation of state $w$ does not cross $-1$ at the $1\sigma$ confidence level, whereas in the HDE model, it marginally falls below this threshold. Upon incorporating CMB data, we observe that in the HDE model, the parameter $c<1$ and $w$ crosses $-1$ at a level beyond $10\sigma$. Conversely, for the IHDE model, the likelihood of $w$ crossing $-1$ is considerably diminished, implying that the introduction of interaction within the HDE model could potentially resolve or mitigate the cosmic big rip conundrum. Furthermore, our analysis reveals that the HDE and IHDE models are statistically as viable as the $\Lambda$CDM model when assessing Bayesian evidence with DESI BAO data combined with SN data. However, when CMB data are added, the HDE and IHDE models are significantly less favored compared to the $\Lambda$CDM model. Our findings advocate for further exploration of the HDE and IHDE models using forthcoming, more precise late-universe observations.

    ↳ astro-ph.COgr-qchep-phEPJC(2025)·114 citations
31. 31*

    Damping of density oscillations from bulk viscosity in quark matter

    José Luis Hernández🇪🇸 · Cristina Manuel🇪🇸 · Laura Tolos🇪🇸

    In this contribution, we extend the discussion about the calculation of the bulk viscosity of quark matter in the normal phase due to electroweak processes and its effect on the damping of baryon density oscillations that might occur in the coalescence of two compact stars. Employing the EoSs from the MIT bag model and perturbative quantum chromodynamics (pQCD) up to $\mathcal{O}({\alpha }_s)$, we analyze our results varying densities in the range of temperatures from 0 to 10 MeV for frequencies around 1 kHz. Our estimates show that bulk viscous effects might play a relevant role during the postmerger stage if the system reaches a deconfined quark matter phase.

    ↳ nucl-thastro-ph.HEhep-phPoS(2025)·0 citations
32. 32*

    Strange and charm quark contributions to the muon anomalous magnetic moment in lattice QCD with twisted-mass fermions

    C. Alexandrou🇨🇾 · S. Bacchio🇨🇾 · A. De Santis🇮🇹 · A. Evangelista🇮🇹 · J. Finkenrath🇨🇭 · R. Frezzotti🇮🇹 · G. Gagliardi🇮🇹 · M. Garofalo🇩🇪 · N. Kalntis🇨🇭 · B. Kostrzewa🇩🇪 · V. Lubicz🇮🇹 · F. Pittler🇨🇾 and 6 other authors

    We present a lattice calculation of the Hadronic Vacuum Polarization (HVP) contribution of the strange and charm quarks to the anomalous magnetic moment of the muon in isospin symmetric QCD. We employ the gauge configurations generated by the Extended Twisted Mass Collaboration (ETMC) with $N_f=2+1+1$ flavors of Wilson-clover twisted-mass quarks at five lattice spacings and at values of the quark mass parameters that are close and/or include the isospin symmetric QCD point of interest. After computing the small corrections necessary to precisely match this point, and carrying out an extrapolation to the continuum limit based on the data at lattice spacings $a\simeq 0.049,0.057,0.068,0.080$~fm and spatial lattice sizes up to $L\simeq 7.6$~fm, we obtain $a_{\mu }^{\mathrm{HVP}}(s)=(53.57\pm 0.63)\times 10^{-10}$ and $a_{\mu }^{\mathrm{HVP}}(c)=(14.56\pm 0.13)\times 10^{-10}$, for the quark-connected strange and charm contributions, respectively. Our findings agree well with the corresponding results by other lattice groups.

    ↳ hep-lathep-phPRD(2025)·71 citations
33. 33*

    A consistency relation for induced gravitational wave anisotropies

    Julián Rey🇩🇪

    We show that the anisotropies in the spectrum of gravitational waves induced by scalar modes after the end of inflation in canonical, single-field models are completely determined by the tilt of the scalar and tensor power spectra. The latter contains information about anisotropies produced due to the propagation of the tensor modes in an inhomogeneous Universe, whereas the former represents the anisotropies generated at the time of production and arise only when non-Gaussian corrections to the angular power spectrum are considered. Our proof takes into account all scalar interactions in the cubic inflaton Lagrangian.

    ↳ astro-ph.COgr-qchep-ph8 citations
34. 34*

    Nuclear correlation functions using first-principle calculations of lattice quantum chromodynamics

    Debsubhra Chakraborty🇮🇳 · Piyush Srivastava🇮🇳 · Arpith Kumar🇮🇳 · Nilmani Mathur🇮🇳

    Exploring nuclear physics through the fundamental constituents of the strong force -- quarks and gluons -- is a formidable challenge. While numerical calculations using lattice quantum chromodynamics offer the most promising approach for this pursuit, practical implementation is arduous, especially due to the uncontrollable growth of quark-combinatorics, the so-called Wick-contraction problem of nuclei. We present here two novel methods providing a state-of-the-art solution to this problem. In the first, we exploit randomized algorithms inspired from computational number theory to detect and eliminate redundancies that arise in Wick contraction computations. Our second method explores facilities for automation of tensor computations -- in terms of efficient utilization of specialized hardware, algorithmic optimizations, as well as ease of programming and the potential for automatic code generation -- that are offered by new programming models inspired by applications in machine learning (e.g., TensorFlow). We demonstrate the efficacy of our methods by computing two-point correlation functions for Deuteron, Helium-3, Helium-4 and Lithium-7, achieving at least an order of magnitude improvement over existing algorithms with efficient implementation on GPU-accelerators. Additionally, we discover an intriguing characteristic shared by all the nuclei we study: specific spin-color combinations dominate the correlation functions, hinting at a potential connection to an as-yet-unidentified symmetry in nuclei. Moreover finding them beforehand can reduce the computing time further and substantially. Our results, with the efficiency that we achieved, suggest the possibility of extending the applicability of our methods for calculating properties of light nuclei, potentially up to A ~12 and beyond.

    ↳ hep-lathep-phnucl-thPRD(2024)·3 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.