Mon·Aug 25, 2025Monday·August 25, 2025

1. 01*

   Gravitational Waves and Cosmological Observables from First-Order Phase Transitions: Thermal Corrections at Low Temperature

   Katharena Christy🇺🇸 · James B. Dent🇺🇸 · Sumit Ghosh🇮🇳 · Jason Kumar🇺🇸 · J. O'Thello Ward🇺🇸

   We consider the impact on cosmological first-order phase transitions (FOPTs) of low-temperature thermal corrections to the effective potential. These are corrections from degrees of freedom whose field-dependent masses in the true vacuum are much larger than the nucleation temperature, though in the false vacuum the field-dependent masses may be much smaller than the nucleation temperature. We focus on the regime in which the thin-wall approximation is valid, and in which these corrections are small enough that they do not alter the vacuum structure of the theory. Although the general form of these corrections to the thermal effective potential can be quite complicated, we argue that the net effect of all such corrections can be well-modeled in this limit with a single new parameter. We determine the shift in the parameters of the FOPT in terms of this new parameter, and the impact on gravitational wave signals and cosmological observables.

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

   Angular phase-space integrals with four denominators through Mellin--Barnes

   Taushif Ahmed🇩🇪 · Syed Mehedi Hasan🇩🇪 · Andreas Rapakoulias🇩🇪

   We compute four-denominator angular phase-space integrals using the Mellin--Barnes (MB) technique in dimensional regularisation. Independent of the scattering process, an angular integral can be categorised based on the nature of the momenta appearing in the denominators. We address all scenarios involving fully massless and massive momenta. We present a partial fraction decomposition that relates angular integrals with multiple massive momenta to those with a single massive momentum. By solving six- and seven-fold MB integrals, we express the final results up to the finite order in the dimensional regulator in terms of Goncharov polylogarithms.

   hep-phhep-thmath-phmath.MPJHEP(2025)·3 citations
3. 03*

   Transport Properties of QGP within a Bayesian Holographic QCD Model

   Bing Chen🇨🇳 · Liqiang Zhu🇨🇳 · Xun Chen🇨🇳 · Defu Hou🇨🇳 · Xurong Chen

   Using a holographic QCD model augmented by Bayesian inference, we calculate key transport coefficients of the quark-gluon plasma (QGP)$\text{-}$including the drag force, jet quenching parameter, heavy quark diffusion coefficient, and shear and bulk viscosities$\text{-}$at finite temperature and chemical potential. Posterior parameter distributions at the 68\% and 95\% confidence levels (CL), as well as the maximum a posteriori (MAP) estimates, are employed to quantify uncertainties. Our findings indicate that the diffusion coefficient within the Bayesian credible regions aligns with lattice QCD results for $T\sim 1.2T_c$ to $2T_c$, and is consistent with ALICE experimental measurements near $T_c$. The jet quenching parameter obtained from the Bayesian analysis agrees with RHIC and LHC data, while viscosity coefficients show compatibility with existing literature. These results demonstrate the efficacy of a Bayesian holographic approach in elucidating the nonperturbative transport properties of QCD matter.

   hep-phNucl.Sci.Tech.(2026)·6 citations
4. 04*

   A natural realization of inverse seesaw model in a non-invertible selection rule

   Shilpa Jangid🇮🇳 · Hiroshi Okada🇨🇳

   We propose natural hierarchies among neutral fermions in a framework of inverse seesaw, imposing a $Z_3$ Tambara-Yamagami fusion rule which is applied to our phenomenology. Under the symmetry, the Majorana mass terms for $N_R$ and $N_L$ are forbidden at tree level. However they are generated at one-loop level where the symmetry is dynamically broken. In order to realize such loop corrections, we introduce neutral boson and fermion either of which can be an appropriate dark matter candidate. Finally, we show the best fit value of the neutrino sector for normal and inverted hierarchies referring recent experimental results.

   hep-ph15 citations
5. 05*

   Topological Stabilization via Higgs and $Z$-Boson Mediated Repulsions in Electroweak Monopole-Antimonopole Pairs

   Dan Zhu🇨🇳 · Xurong Chen🇨🇳 · Khai-Ming Wong🇲🇾

   We identify two distinct repulsive mechanisms in the Cho-Maison monopole-antimonopole pair (MAP) configuration. Our results show that the Higgs-mediated repulsion exhibits a non-monotonic dependence on both topological charge and Higgs self-coupling, confirming its topological origin while revealing a mass-controlled range transition that deviates from the exponential form of a Yukawa potential. Simultaneously, the $Z$-boson field generates localized repulsive cores of radius $R_c\approx 0.8m_W^{-1}$, consistent with the weak interaction scale. The collaborative effect of these mechanisms -- operating in different physics regimes -- counteracts the magnetic attraction, establishing a stabilization paradigm for the Cho-Maison MAP that extends naturally to other topological solitons in the Standard Model and various systems described by effective field theories.

   hep-phhep-thPRD(2026)·1 citation
6. 06*

   Analysis of $B\to K{M}_X$ and $B\to K^{\ast }{M}_X$ decays in scalar- and vector-mediator dark-matter scenarios

   Alexander Berezhnoy🇷🇺 · Wolfgang Lucha🇦🇹 · Dmitri Melikhov🇷🇺

   The surprising excess of missing-energy events far beyond all standard-model expectations in the weak decays of the charged ground-state $B^{+}$ meson into some charged strange meson, rather recently observed by the Belle-II experiment, may (easily) be explained by the decay of the $B$ meson into the strange meson and a pair of dark-matter fermion and antifermion, mediated by an (intermediate) scalar or vector boson. Thorough inspections of both the total and the differential widths of these decays provide, among others, a simple means for the (straightforward) discrimination of such mediator boson's scalar or vector nature.

   hep-phMoscow Univ.Phys.Bull.(2025)·1 citation
7. 07*

   Renormalization Group Running of the Minimal Leptophilic Dark Matter Model toward a UV Completion

   Osamu Seto🇯🇵 · Tetsuo Shindou🇯🇵 · Takanao Tsuyuki🇯🇵

   We study the renormalization group running of the coupling constants in a minimal leptophilic dark matter model in which a Standard Model singlet fermion, acting as the dark matter (DM) candidate, couples exclusively to right-handed charged leptons via a new charged scalar mediator. Reproduction of the observed thermal relic abundance of the DM candidate requires sizable Yukawa couplings, and such sizable Yukawa couplings can significantly affect the renormalization group evolution of the model parameters. We examine the conditions that the model remains perturbative and the vacuum stability is maintained up to high-energy scales. We find that the parameter space is severely constrained to ensure the perturbativity and the vacuum stability up to the Planck scale. In particular, the masses of the dark matter and the charged scalar mediator should be smaller than about 350 GeV and can be tested by future collider experiments. The lower bound of the dark matter mass that is larger than a few GeV is also obtained by perturbativity.

   hep-phPRD(2025)·1 citation
8. 08*

   Nonperturbative Dynamics in D-meson Mixing

   Lovro Dulibić🇭🇷 · Blaženka Melić🇭🇷 · Alexey A. Petrov🇺🇸

   Theoretical predictions for the $D^0\overline{D^0}$ mixing parameters fall significantly short of experimental measurements, with discrepancies spanning several orders of magnitude. This gap is mainly due to the Glashow-Iliopoulos-Maiani (GIM) mechanism, which suppresses leading-order contributions by high powers of $m_s/m_c$. However, higher-order corrections and nonperturbative effects could reduce this suppression, especially through flavor $SU(3{)}_F$ symmetry breaking. In this work, we investigate the long-distance contributions from QCD condensates, including, for the first time, the effects of mixed quark-gluon and four-quark condensates. Our results show an increase in the predicted values of $D^0\overline{D^0}$ mixing parameters by two orders of magnitude compared to perturbative NLO result, providing valuable insights into nonperturbative QCD dynamics. Although the theoretical estimates still fall below experimental values, this study represents an important step toward narrowing the gap between theory and observation, highlighting the significance of higher-order $1/m_c$ QCD effects in understanding $D^0\overline{D^0}$ mixing.

   hep-phJHEP(2025)·3 citations
9. 09*

   Probing the Scotogenic Dirac Model with FIMP Dark Matter and $\Delta N_{\mathrm{eff}}$

   Shu-Yuan Guo🇨🇳 · Man-Yu Zhao🇨🇳

   We study a feebly interacting massive particle realization of the Scotogenic Dirac Model in which the lightest neutral fermion $N_1$ serves as a dark matter candidate, produced via the freeze-in or super-WIMP mechanism. The model generates Dirac neutrino masses at one loop, resulting in a rank-2 mass matrix that predicts one nearly massless neutrino. We analyze the DM relic density for various next-to-lightest odd particles (NLOPs), finding that coannihilation effects and enhanced annihilation channels are crucial for achieving the correct thermal freeze-out abundance of the NLOP. We provide a detailed analysis of the model's implications for the effective number of relativistic species, $\Delta N_{\mathrm{eff}}$, which receives contributions from both a thermal bath of right-handed neutrinos and non-thermal energy injection due to late NLOP decays. Through an extensive parameter scan, we identify viable parameter space for all NLOP candidates that satisfies constraints from DM relic density, lepton flavor violation, Big Bang Nucleosynthesis, Cosmic Microwave Background, and $\Delta N_{\mathrm{eff}}$.

   hep-phCPC(2026)·4 citations
10. 10*

    Study the decays of ${\chi }_{cJ}(J=0,1,2)$ to light meson pairs with SU(3) flavor symmetry/breaking analysis

    Bo Lan🇨🇳 · Qin-Ze Song🇨🇳 · Jin-Huan Sheng🇨🇳 · Yi Qiao🇨🇳 · Ru-Min Wang🇨🇳

    Based on available experimental results on ${\chi }_{cJ}(J=0,1,2)$ decays, we investigate the ${\chi }_{cJ}\to PP$, $VV$, $PV$, and $PT$ decays by using SU(3) flavor symmetry/breaking approach, where $P$, $V$, and $T$ denote light pseudoscalar, vector, and tensor mesons, respectively. With the decay amplitude relations determined by SU(3) flavor symmetry/breaking, we present the branching ratios for all ${\chi }_{cJ}\to PP$ and ${\chi }_{cJ}\to VV$ modes, including ones without experimental data. While theoretical considerations strongly suppress or even forbid most ${\chi }_{cJ}\to PV$ and $PT$ decays, we also provide quantitative predictions constrained by existing experimental data. Our results are expected to be accessible in future experiments at BESIII and the planned Super Tau-Charm Facility.

    hep-phCPC(2025)·1 citation
11. 11*

    Probing scalar non-standard interaction of supernova neutrinos in next-generation neutrino experiments

    Sudipta Das🇺🇸 · Mary Hall Reno🇺🇸

    A new neutrino-matter interaction can potentially affect neutrino propagation through matter. In this work, we explore the impact of a flavor-conserving scalar-mediated non-standard neutrino interaction in the supernova neutrino flux. We observe that the presence of a scalar interaction involving muon and tau neutrinos (parameterized as ${\eta }_{\mu \mu }$ and ${\eta }_{\tau \tau }$, respectively) can invert the neutrino mass eigenstate in which three neutrino flavor states are produced inside the supernova core, resulting in a significant modification of the electron neutrino flux from the supernova reaching the Earth. In the context of the DUNE experiment, we estimate the number of supernova neutrino events in the presence of scalar non-standard neutrino interaction ${\eta }_{\mu \mu }$ or ${\eta }_{\tau \tau }$ and contrast with the case without scalar-mediated non-standard interactions. Our results indicate that such scalar interactions introduce a new degeneracy in the measurement of neutrino mass ordering from supernova neutrinos. We show how the ${\bar{\nu }}_e$ event distribution in Hyper-Kamiokande experiment may help resolve the degeneracy between a model with new scalar interactions for normal ordered neutrino masses and the standard model with inverted mass ordering for a galactic supernova.

    hep-phJCAP(2026)·4 citations
12. 12*

    Scalar non-standard neutrino interactions in Galactic supernovae

    Bhaskar Dutta🇺🇸 · Aparajitha Karthikeyan🇺🇸 · Nityasa Mishra🇺🇸 · Yago Porto🇧🇷 · Louis E. Strigari🇺🇸

    We analyze the prospects for studying scalar non-standard interactions (SNSI) using the neutrino burst from a Galactic supernova. SNSI modify the resonant flavor conversion and, correspondingly, the neutronization burst signal, and may be identifiable in future multi-tonne-scale experiments such as DUNE. We show that, in the presence of SNSI, neutrinos propagating out of the dense supernova environment acquire a density-squared-dependent contribution to their mass-squared differences, which in turn modifies the energy levels of the neutrino mass eigenstates. This phenomenon is not present in less dense environments like the Earth or the Sun. For a given mass ordering, supernova neutrinos can improve the sensitivity to SNSI parameters by up to four orders of magnitude compared to that achievable with solar or terrestrial neutrino sources.

    hep-phastro-ph.HEastro-ph.SR5 citations
13. 13*

    Searching for neutrino polarizability at DUNE

    Sam Carey🇺🇸 · Pedro Machado🇺🇸 · Gil Paz🇺🇸 · Alexey A. Petrov🇺🇸 · Alexandre Sousa🇺🇸 · Michele Tammaro🇮🇹 · Jure Zupan🇺🇸

    We perform an initial study of DUNE's sensitivity to enhanced neutrino polarizability within models of light scalar mediators. We identify two possible signatures of polarizability due to neutrino scattering on electrons and due to coherent scattering on argon nuclei. These result in either one or two separated electromagnetic showers, respectively, with no associated hadronic activity. For each signature we compute the signal rates and the relevant backgrounds, obtaining the projected reach of the DUNE near detector. We then compare this with the current astrophysical and terrestrial bounds on light scalar models coupling to neutrinos and/or photons.

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

    Simulation-Based Inference for Direction Reconstruction of Ultra-High-Energy Cosmic Rays with Radio Arrays

    Oscar Macias🇺🇸 · Zachary Mason🇺🇸 · Matthew Ho🇺🇸 · Arsène Ferrière🇫🇷 · Aurélien Benoit-Lévy🇫🇷 · Matías Tueros🇦🇷

    Ultra-high-energy cosmic-ray (UHECR) observatories require unbiased direction reconstruction to enable multi-messenger astronomy with sparse, nanosecond-scale radio pulses. Explicit likelihood methods often rely on simplified models, which may bias results and understate uncertainties. We introduce a simulation-based inference pipeline that couples a physics-informed graph neural network (GNN) to a normalizing-flow posterior within the Learning the Universe Implicit Likelihood Inference framework. Each event is seeded by an analytic plane-wavefront fit; the GNN refines this estimate by learning spatiotemporal correlations among antenna signals, and its frozen embedding conditions an eight-block autoregressive flow that returns the full Bayesian posterior. Trained on about $8,000$ realistic UHECR air-shower simulations generated with the ZHAireS code, the posteriors are temperature-calibrated to meet empirical coverage targets. We demonstrate a sub-degree median angular resolution on test UHECR events, and find that the nominal 68% highest-posterior-density contours capture $71\%\pm 2\%$ of true arrival directions, indicating a mildly conservative uncertainty calibration. This approach provides physically interpretable reconstructions, well-calibrated uncertainties, and rapid inference, making it ideally suited for upcoming experiments targeting highly inclined events, such as GRAND, AugerPrime Radio, and BEACON.

    ↳ astro-ph.HEastro-ph.IMhep-phPRD(2026)·2 citations
15. 15*

    Causality and Stability in Relativistic Hydrodynamics

    Sukanya Mitra🇮🇳

    The causality and stability of a relativistic hydrodynamic theory is shown to require a consensus between, either (i) newer degrees of freedom apart from the fundamental fluid fields, or (ii) a general hydrodynamic frame other than the Landau or Eckart compromising the field's first principle definition, unless the non-equilibrium derivative correction goes to infinity. Any finitely truncated derivative correction (no matter how high it is) is shown to lead to an acausal theory, unless the corrections are infinitely summed up to include all orders. From an underlying microscopic theory, an exact form of relativistic hydrodynamics has been derived which establishes that the resummation of all order temporal derivatives is essential for causality, which finally 'integrated in' as newer degrees of freedom.

    ↳ nucl-thhep-phhep-thJ.Subatomic Part.Cosmol.(2025)·1 citation
16. 16*

    Transport coefficients of hot and dense matter in relativistic heavy-ion collisions

    Sukanya Mitra🇮🇳

    The transport coefficients are known as the measure of system interactions, as well as the dynamical input of the hydrodynamic evolution equations of an expanding system created in the relativistic heavy ion collisions. In the current analysis, they have been evaluated for strongly interacting quark-gluon plasma system as well as hot hadronic media. The medium effects for an interacting QCD system have been introduced through a quasiparticle model. The same for a hadronic system has been captured via the in-medium self-energy correction using thermal field theory. The resulting behavior of the transport coefficients shows significant modification with respect to the estimations made in vacuum or using ideal equation of state.

    ↳ nucl-thhep-phhep-thJ.Subatomic Part.Cosmol.(2025)·0 citations
17. 17*

    Cosmological Constraints on Neutrino Masses in a Second-Order CPL Dark Energy Model

    Shubham Barua🇮🇳 · Shantanu Desai🇮🇳

    Recent DESI results indicate a strong preference for dynamical dark energy (DE) when baryon acoustic oscillation (BAO) measurements are combined with supernovae (SNe) and cosmic microwave background (CMB) data using the Chevallier-Polarski-Linder (CPL) parameterization. We analyze the exponential (EXP) parameterization, which introduces a second-order correction to CPL. We determine and compare the 95% upper bounds on the sum of neutrino masses for three dark energy (DE) models -- $\Lambda$CDM, CPL, and EXP -- across four neutrino mass hierarchies (1 massive/2 massless, degenerate, normal, inverted) and multiple dataset combinations (CMB$+$BAO, CMB$+$BAO$+$PantheonPlus, CMB$+$BAO$+$DESY5), employing both Bayesian and frequentist frameworks with physical lower limits from oscillation experiments (0.059 eV and 0.11 eV). Our results show that CPL yields tighter ($\lesssim 10$%) bounds compared to EXP. We further confirm earlier findings that neutrino mass constraints are only mildly sensitive to the assumed hierarchy and that the frequentist bounds are tighter than Bayesian ones. Furthermore, the imposed oscillation lower limits, the datasets used and the DE parameterizations play a crucial role in the inferred cosmological neutrino mass bounds. For the datasets, hierarchies, and DE parameterizations considered, we find no statistically significant evidence for nonzero neutrino mass consistent with oscillation lower limits.

    ↳ astro-ph.COhep-phPhys.Dark Univ.(2026)·8 citations
18. 18*

    Energy-momentum response to metric perturbations in the fluid dynamic regime

    Tim Stoetzel · Rebekka Fechtner · Stefan Floerchinger🇩🇪

    The interplay of relativistic fluid dynamics and spacetime geometry is discussed in the regime of small wave numbers and frequencies. A combination of gravitational Ward identities and fluid dynamic equations of motion in the Mueller-Israel-Stewart formulation is used to explicitly determine the retarded linear response of the energy-momentum tensor to metric perturbations. We also discuss applications to gravitational wave production and the damping of gravitational waves in a relativistic fluid.

    ↳ gr-qchep-phPRD(2025)·4 citations
19. 19*

    Hubble's Law in Heavy Ion Collisions

    N.V. Kolomoyets🇷🇺 · O.V. Teryaev🇷🇺 · V. Voronyuk🇷🇺

    The evolution of the "microscopic" Hubble parameter related to the expansion of matter born in heavy-ion collisions was obtained for nucleons and pions. The calculations were carried out within the parton-hadron-string dynamics (PHSD) transport model. Au+Au collisions with $\sqrt{s_{NN}}=7.8$ GeV at $b=2.5,5.0,7.5$, and $10.0$ fm were considered. A new method for determining the "microscopic" Hubble parameter from simulated data was used. The ballistic motion was obtained for the longitudinal direction after the separation of the nuclei. In earlier times, the evolution of the "microscopic" Hubble parameter in this direction was more complicated. For transverse directions, an exponential low-time asymptotics of the Hubble parameter was observed. The obtained values of the "microscopic" Hubble parameter are about 40 orders of magnitude higher than the cosmological Hubble constant.

    ↳ nucl-thhep-phPRC(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.