Fri·Feb 6, 2026Friday·February 6, 2026

1. 01*

   Distinguishing Dirac and Majorana Neutrinos: Resonant Spin-Flavor Precession of GeV-Scale Astrophysical Transients

   D. Delepine🇲🇽 · A. Yebra🇲🇽

   We present a unified formalism to study the Resonant Spin-Flavor Precession (RSFP) of high-energy ($\sim 1$ GeV) transient astrophysical neutrinos as a probe of their fundamental Dirac or Majorana nature. Current MeV scale neutrino studies face stringent restrictions: efficient core RSFP for Dirac supernova neutrinos is excluded by SN1987A cooling bounds, while solar neutrino conversion is tightly constrained by Borexino data. We show that considering the 1 GeV energy scale accessible through solar flares modifies the resonance conditions. For 1 GeV solar flare neutrinos, the resonance shifts to the tachocline and convective zones, where toroidal magnetic fields ($B\sim 50$ kG) induce adiabatic spin flavor conversion. In contrast, for supernovae, to avoid the cooling constraints, the RSFP is moved from the core supernovae to the stellar envelope. As for non thermal 1 GeV supernova neutrinos, the resonance is located in the dilute stellar wind where magnetic fields are negligible, suppressing RSFP and preserving the flux, one can use these non-thermal neutrinos as a candle to calibrate our signal, reducing its dependence on astrophysical uncertainties. Evaluating these helicity transitions through a density matrix approach, we predict distinct asymmetries in Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS) and neutrino-electron scattering cross-sections for solar flare neutrinos and supernova neutrinos. Our proposal provides a viable method to distinguish Dirac from Majorana neutrinos and to probe magnetic moments down to ${\mu }_{\nu }\sim 10^{-14}{\mu }_B$.

   hep-phPRD(2026)·1 citation
2. 02*

   Solar Flares as a Probe of Neutrino Nature: Distinguishing Dirac and Majorana via Resonant Spin-Flavor Precession

   D. Delepine🇲🇽 · A. Yebra🇲🇽

   Resonant Spin-Flavor Precession (RSFP) of solar neutrinos is studied using the quantum density matrix formalism, explicitly taking into account collisional decoherence and solar matter density profiles. The transition probabilities for standard ${}^8$B solar neutrinos ($E\approx 10$ MeV) and ultra-high-energy flare neutrinos ($E\gtrsim 1$ GeV) under three magnetic field hypotheses: core-concentrated (Wood-Saxon), tachocline-confined (Gaussian), and turbulent convective (Power Law) are compared. For standard LMA parameters, we show the resonance for 10 MeV neutrinos is strictly confined to the deep solar core ($r<0.2R_{\odot }$), rendering standard solar neutrinos insensitive to outer magnetic fields. Conversely, for 1 GeV flare neutrinos, the resonance shifts to the tachocline and convective zones, where strong fields ($B\sim 50$ kG) drive efficient spin conversion. We apply this effect to compute the difference between Dirac or Majorana neutrino scattering cross section as electron-neutrino scattering and Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS). We show that significant asymmetry in these cross section are possible allowing in case of detection to distinguish between Dirac or Majorana neutrinos. In case of null observation, we show that this method can potentially improved the limit on the neutrino magnetic moment by one order to magnitude compared to current limits.

   hep-ph1 citation
3. 03*

   Novel Signatures of Heavy Neutral Lepton at Muon Collider

   Xue-Xin Zhang🇨🇳 · Zhi-Long Han🇨🇳 · Fei Huang🇨🇳 · Honglei Li🇨🇳

   The Higgs-strahlung process ${\ell }^{+}{\ell }^{-}\to Zh$ is one of the most important production channels of the standard model Higgs boson $h$ at the lepton colliders. The cross section reaches the maximum value slightly above the threshold $\sqrt{s}\sim m_Z+m_h$, and decreases as $\sim 1/s$ at high energies. In the gauged extension models, the new gauge boson $Z^{\prime }$ and heavy Higgs boson $H$ exist after the symmetry breaking. The heavy Higgs-strahlung process ${\ell }^{+}{\ell }^{-}\to Z^{\prime }H$ would also reach the maximum cross section around the threshold $\sqrt{s}\sim m_{Z^{\prime }}+m_H$. Therefore, the future high energy lepton colliders, such as the TeV scale muon collider, are promising to probe this new process. If heavy neutral lepton $N$ is introduced to generate the tiny neutrino masses via seesaw mechanism, novel signatures could arise from ${\mu }^{+}{\mu }^{-}\to Z^{\prime }H\to NN+NN\to 4{\mu }^{\pm }+4J$ and ${\mu }^{+}{\mu }^{-}\to Z^{\prime }H\to {\mu }^{+}{\mu }^{-}+NN\to 3{\mu }^{\pm }+{\mu }^{\mp }+2J$, where the fat-jets $J$ come from the hadronic decay of $W$ bosons. In this paper, we investigate the same-sign tetralepton signature $4{\mu }^{\pm }+4J$ and the same-sign trilepton signature $3{\mu }^{\pm }+{\mu }^{\mp }+2J$ at the 3 TeV and 10 TeV muon collider.

   hep-phhep-exJHEP(2026)·1 citation
4. 04*

   Quantum Fisher Information Revealing Parameter Sensitivity in Long-Baseline Neutrino Experiments

   Bhavna Yadav🇮🇳 · Amir Subba🇨🇳 · Yu Shi🇨🇳

   Determination of the leptonic CP-violating phase ${\delta }_{\mathrm{CP}}$, the atmospheric mixing angle ${\theta }_{23}$, and the mass-squared difference $\Delta m_{31}^2$ constitutes a primary objective of current and next-generation long-baseline neutrino experiments. We employ Quantum Fisher Information (QFI) to quantify the maximum information that the neutrino quantum state contains about these oscillation parameters, treating the neutrino as an evolving pure quantum state. Computing the QFI as a function of the baseline-to-energy ratio $L/E$ for benchmark parameter sets from NuFit-6.0, we find distinct sensitivity hierarchies and $L/E$-dependent structures. Specifically, ${\delta }_{\mathrm{CP}}$ and ${\theta }_{23}$ exhibit bimodal QFI profiles with peaks around $L/E\sim 500$ and $1500km/GeV$, reaching $F_Q({\delta }_{\mathrm{CP}})\sim 0.15$ and $F_Q({\theta }_{23})\sim 15$, respectively. In contrast, $F_Q(\Delta m_{31}^2)$ increases rapidly with $L/E$ over the range considered, reaching values of order $10^7$. This hierarchy indicates that, within the considered single-parameter framework, the neutrino state carries substantially greater intrinsic quantum sensitivity to $\Delta m_{31}^2$ than to ${\theta }_{23}$ or ${\delta }_{\mathrm{CP}}$. We further compare the QFI with the classical Fisher information (CFI) obtained from flavor-transition probabilities, showing how much of the available information can be extracted through this specific measurement. For a fixed DUNE baseline, matter effects substantially enhance the QFI for ${\delta }_{\mathrm{CP}}$ in the few-GeV region, while producing only minor modifications for ${\theta }_{23}$ and $\Delta m_{31}^2$. These results show that the information available for estimating the three oscillation parameters differs significantly, and that the flavor-probability measurement does not always extract all the information available in the quantum state.

   hep-phquant-ph10 citations
5. 05*

   Resolved photoproduction of the $B_c$ meson in electron-proton collisions

   Na Cai🇨🇳 · Xi-Jie Zhan🇨🇳 · Tai-Fu Feng🇨🇳

   We present a systematic study of $B_c$ meson photoproduction at electron--proton colliders within the framework of nonrelativistic QCD (NRQCD) factorization. In addition to the dominant direct channel $\gamma +g\to B_c+X$, we include resolved contributions initiated by $g+g$ and $q+\bar{q}(q=u,d,s)$ subprocesses. Total cross sections and transverse-momentum distributions are calculated for several collider configurations, including HERA, LHeC, FCC-$ep$, and EIC. The numerical results show that the direct $\gamma +g$ channel provides the leading contribution over the entire kinematic range. However, the resolved $g+g$ channel yields a non-negligible correction, reaching the level of $\mathcal{O}(10\%)$ in the low-$p_T$ region where most events are produced, and it becomes increasingly important at higher collision energies. The $q+\bar{q}$ channel is found to be numerically insignificant.

   hep-phPRD(2026)·1 citation
6. 06*

   Renormalization of the Standard Model effective field theory to dimension eight

   Álvaro Díaz-Carmona🇪🇸

   The Standard Model Effective Field Theory (SMEFT) provides a powerful, model-independent framework to explore deviations from the Standard Model (SM) by parametrising potential new physics through higher-dimensional operators. This thesis investigates the renormalisation structure of SMEFT, focusing on dimension-eight operators, which are increasingly relevant in precision analyses and in models where dimension-six effects are suppressed. We review renormalisation in quantum field theory, emphasising dimensional regularisation and the $\overline{\text{MS}}$ scheme, and outline the conceptual foundations of EFTs. One of the central results of this work is the systematic construction and classification of bosonic operators in SMEFT at dimension eight, employing Group Theory techniques and removing redundancies by working in momentum space. Building on this operator basis, we compute the complete one-loop renormalisation group equations (RGEs) involving insertions of dimension-eight-or-lower operators. This includes pure dimension-eight effects, pairs of dimension-six operators and lepton-number-violating sectors. Our calculations use an off-shell Green's function basis and leverage algebraic simplifications derived from symmetry and gauge invariance. These results are applied to positivity bounds and oblique parameters, providing essential tools for consistent SMEFT analyses across energy scales. The findings extend SMEFT's theoretical reach and support its use in high-precision phenomenology.

   hep-ph0 citations
7. 07*

   Transport of $D^0$ meson in hadronic matter in the domain of Non-Extensive statistics

   Aditya Kumar Singh🇮🇳 · Swatantra Kumar Tiwari🇮🇳

   In this work, we investigate the drag and diffusion coefficients of $D^0$ meson propagating through a hadronic thermal bath by employing the Fokker Planck equation within the framework of Tsallis non extensive statistics. The non extensive parameter, $q$ accounts for the deviation from equilibrium and provides a more realistic description of the medium that is not perfectly thermalized. The hadronic bath, consisting of various mesonic and baryonic species, is characterized by different mass cutoffs that control the spectral composition of the medium. Our analysis shows that both the drag, $F$ and momentum diffusion coefficients, $\Gamma$ increases with temperature and also increases with increasing $q$ and mass cutoff. The spatial diffusion coefficient, $D_x$ exhibits a decreasing trend with temperature $T$, $q$ and mass cutoff which highlights the significant influence of non-equilibrium effects and hadronic composition on the transport behaviour of $D^0$ meson, offering valuable insights into the thermal and dynamical properties of the hadronic phase in heavy ion collisions. In this study while calculating the spatial diffusion coefficient, $D_x$ we observe that beyond $q$ = 1.24, $D_x$ goes below to the lower limit proposed in Ads/CFT theory. This suggests that 1.24 is the upper limit of non extensive parameter, $q$.

   hep-phhep-exnucl-th1 citation
8. 08*

   Simulating first-order phase transition during inflation

   Jintao Zou🇨🇳 · Ligong Bian🇨🇳 · Shao-Jiang Wang🇨🇳

   Ending the inflation by vacuum decay is considered infeasible due to the graceful exit problem. Even if considering an alternative field other than the inflaton to realize a first-order phase transition (FoPT) during inflation, it is usually challenging for concrete model building, as bubble nucleations might not be fast and dense enough to successfully end the inflation. In this work, we propose a FoPT at the grand-unification-theory (GUT) scale within the Starobinsky inflation. The key construction is an exponentially evolving potential barrier dynamically controlled by the rolling inflaton, so that almost no bubble is nucleated during the early inflationary era, but with massive bubble nucleations near the end of inflation. With lattice numerical simulations, we have successfully tested this GUT-FoPT during Starobinsky inflation, and the resulting gravitational-wave energy density spectrum reproduces previous analytical estimation with a distinctive oscillation feature at high frequencies.

   hep-phastro-ph.COhep-thPRD(2026)·7 citations
9. 09*

   Electromagnetic polarizabilities of the triplet hadrons in heavy hadron chiral perturbation theory

   Hao Dang🇨🇳 · Liang-Zhen Wen🇨🇳 · Yan-Ke Chen🇨🇳 · Shi-Lin Zhu🇨🇳

   We investigate the electromagnetic polarizabilities of singly heavy mesons and doubly heavy baryons within the framework of heavy hadron chiral perturbation theory up to $\mathcal{O}(p^3)$. We estimate the low-energy constants using the non-relativistic constituent quark model. A striking prediction of our study is the giant electric polarizabilities of the $D^{\ast }$ mesons: ${\alpha }_E({\bar{D}}^{\ast 0})\approx 291.4\times 10^{-4}{\text{fm}}^3$ and ${\alpha }_E(D^{\ast -})\approx -0.4-64.4i\times 10^{-4}{\text{fm}}^3$. These anomalously large values arise from the near-degenerate mass between $D^{\ast }$ and $D\pi$, which are orders of magnitude larger than those of their bottom counterparts. This kinematic coincidence induces a pronounced cusp structure in the chiral loops, reflecting the long-range dynamics of a pion cloud. For doubly heavy baryons, polarizabilities depend strongly on heavy-flavor composition: the $bcq$ system differs markedly from $ccq$ and $bbq$ due to mixing with scalar heavy-diquark states. Using heavy diquark-antiquark symmetry (HDAS), we unify the chiral dynamics of singly heavy mesons and doubly heavy baryons in the heavy-quark limit. The pion-loop contributions dominate the electromagnetic structure of heavy hadrons and provide essential benchmarks for future lattice QCD simulations.

   hep-phhep-exhep-latnucl-thPRD(2026)·2 citations
10. 10*

    Chromomagnetic condensation and perturbative confinement induced by imaginary rotation in SU(2) Yang-Mills Theory

    Lei Zhang🇨🇳 · Kun Xu🇨🇳 · Mei Huang🇨🇳

    We perturbatively investigate the rotation effect on the Polyakov loop potential in SU(2) gauge theroy within a chromomagnetic background. It is observed that the imaginary rotation spontaneously induces both confinement and chromomagnetic condensation at high temperatures, thereby provides a perturbative window to explore non-perturbative dynamics. Compared to the case without including the induced chromomagnetic field, the perturbative confinement transition becomes first-order, with a temperature-dependent phase boundary that asymptotically approaches ${\tilde{\Omega }}_c=\pi /\sqrt{3}$ at high temperatures. This leads to a significantly enriched $\tilde{\Omega }$-$T$ phase diagram characterized by an expanded deconfined region. For real angular velocities, we find that the chromomagnetic condensate decreases with increasing rotation, and that the coupling between rotation, spin, and the chromomagnetic background leads to a cusp in the Polyakov loop potential, suggesting that the underlying dynamics could be more intricate.

    hep-ph3 citations
11. 11*

    Chromomagnetic Condensate in Finite-Temperature SU(2) Yang-Mills Theory under Imaginary Rotation

    Hao-Lei Chen🇨🇳 · Xu-Guang Huang🇨🇳

    We investigate the finite-temperature SU(2) Savvidy model under an imaginary angular velocity. Employing the background-field method, we derive the one-loop effective potential and analyze both its real and imaginary parts. We demonstrate that imaginary rotation modifies the chromomagnetic condensate and the Polyakov loop, and can partially suppress the Nielsen-Olesen instability of the chromomagnetic background. Moreover, a high-temperature expansion shows that imaginary rotation strengthens the effective coupling and that the chromomagnetic field induces a negative contribution to the moment of inertia.

    hep-phPRD(2026)·2 citations
12. 12*

    Neutrino mass ordering in JUNO at risk from scalar NSI induced resonance

    Sandhya Choubey🇸🇪 · Andreas Lund🇸🇪

    The determination of neutrino mass ordering (NMO) is the primary goal of the currently running JUNO reactor experiment. We show that the measurement of NMO at JUNO may severely deteriorate in the presence of non-standard neutrino interactions mediated by a beyond standard model scalar (SNSI). Taking inverted ordering and the lightest neutrino mass at $m_l=0.01$ eV, the NMO sensitivity falls below $2\sigma$ for SNSI parameter values in the range ${\eta }_{ee}<-7.1\times 10^{-3}$ and ${\eta }_{ee}>3.3\times 10^{-3}$. More importantly, for ${\eta }_{ee}\gtrsim 5.7\times 10^{-3}$ the NMO sensitivity in JUNO is completely lost. We show that this is due to the presence of a hitherto unrecognized resonant enhancement of the mixing angle ${\theta }_{12}$, which gives rise to a mass ordering degeneracy.

    hep-phhep-ex5 citations
13. 13*

    Order-$v^2$ relativistic corrections to heavy-quark fragmentation into $P$-wave quarkonium states

    Sai Cui🇨🇳 · Sheng-Juan Jiang🇨🇳 · Guang-Zhi Xu🇨🇳 · Kui-Yong Liu🇨🇳

    Within the framework of nonrelativistic QCD (NRQCD) factorization,and based on the Collins--Soper operator definition of fragmentation functions, we present a systematic calculation of the fragmentation functions for a heavy quark fragmenting into color-singlet $P$-wave quarkonium states. After reproducing and confirming the known leading-order results, we further compute the relativistic corrections up to order $\mathcal{O}(v^2)$. Our analysis applies both to quarkonium systems composed of heavy quarks with the same flavor and to $B_c$-type mesons formed by heavy quarks of different flavors. Numerical results show that, for all color-singlet $P$-wave channels, the $\mathcal{O}(v^2)$ relativistic corrections give sizable negative contributions over most of the momentum-fraction $z$ region. We further compute inclusive cross sections for $P$-wave quarkonium plus charmed hadrons in $e^{+}{e}^{-}$ annihilation via the single photon process up to $\mathcal{O}(v^2)$ by applying our obtained fragmentation functions, and the resulting predictions are consistent with the full fixed-order results in the high-energy region.

    hep-phJHEP(2026)·1 citation
14. 14*

    Induced-Gravity Palatini-Like Higgs Inflation in Supergravity Confronts ACT DR6

    C. Pallis🇬🇷

    We formulate within Supergravity a model of induced-gravity inflation, excellently consistent with ACT DR6, inspired by the Palatini gravity. The inflaton belongs in the decomposition of a conjugate pair of Higgs superfields which lead to the spontaneous breaking of a U(1)B-L symmetry at a scale close to the range (0.102-5.85)x10^16 GeV. The inflaton field is canonically normalized thanks to a real and shift-symmetric contribution into the Kaehler potential. It also includes two separate holomorphic and antiholomorphic logarithmic terms, the argument of which can be interpreted as the coupling of the inflaton to the Ricci scalar. The attainment of inflation allows for subplanckian inflaton values and energy scales below the cut-off scale of the corresponding effective theory. Embedding the model in a B-L extension of the MSSM we show how the mu parameter can be generated and non-thermal leptogenesis can be successfully realized. An outcome of our scheme is split SUSY with gravitino mass in the range (40-60) PeV, which is consistent with the results of LHC on the Higgs boson mass.

    hep-phastro-ph.COhep-thAstronomy(2026)·6 citations
15. 15*

    The Pion Sum Rule beyond the Chiral Limit

    Johan Bijnens🇸🇪 · Nils Hermansson-Truedsson🇬🇧 · Antonio Rodríguez-Sánchez🇪🇸

    The difference between the charged and neutral pion masses can be predicted from a well-known dispersion relation involving an infinite-energy integral over experimental data, the pion sum rule. This relation, however, holds only in the chiral limit. Here we combine several nonperturbative techniques to determine the form of the physical finite-energy integral, thereby generalizing this sum rule to include effects linear in the light-quark masses. We test the dispersion relation using hadronic tau-decay data.

    hep-phJHEP(2026)·1 citation
16. 16*

    Early-universe constraints on the electron mass

    Michela Garramone🇮🇹 · Stefano Gariazzo🇮🇹 · Nicolao Fornengo🇮🇹

    We investigate the impact of a nonstandard electron mass $m_e$ on early-Universe thermal history, focusing on neutrino decoupling and Big Bang Nucleosynthesis (BBN). In the standard cosmology, neutrino--electron interactions keep neutrinos in thermal contact with the electromagnetic plasma until shortly before $e^{\pm }$ annihilation. Varying $m_e$ shifts the decoupling epoch and the entropy transfer from $e^{\pm }$ annihilation, thereby modifying the neutrino energy density and the inferred effective number of relativistic species, $N_{\mathrm{eff}}$. Independently, during BBN the rates of charged-current weak processes, and hence the neutron-to-proton ratio, depend on $m_e$. By confronting BBN predictions for the primordial light-element abundances with observations and imposing cosmological constraints on $N_{\mathrm{eff}}$, we obtain the following $1\sigma$ bounds on $m_e$ in the early Universe: $m_e=0.505_{-0.007}^{+0.006}$ MeV (for the NACRE II nuclear reaction network) or $m_e=0.509_{-0.004}^{+0.005}$ MeV (for the PRIMAT nuclear reaction network). These bounds have been derived by adopting the recent determination of the primordial Helium-4 abundance by the Large Binocular Telescope observations of 54 metal-poor H\,\textsc{ii} regions. If instead we adopt the Particle Data Book Helium-4 abundance, the bounds are: $m_e=0.503_{-0.015}^{+0.011}$ MeV (NACRE II) or $m_e=0.521_{-0.007}^{+0.009}$ MeV (PRIMAT) The obtained allowed ranges are close to the present laboratory value at the level of $\sim 0.4\%-2\%$, depending on the dataset and nuclear network, thus supporting the constancy of the electron mass over cosmological timescales.

    hep-phastro-ph.COPRD(2026)·3 citations
17. 17*

    The EP Model with U(1) (E5)

    John A. Dixon🇨🇦

    Here we add a U(1) gauge theory to the simple EP exotic invariant model in the paper E4. This paper E5 is the fifth in a series of papers En.

    hep-phhep-th0 citations
18. 18*

    Violation of the Conformal Limit at Finite Density: Insights from Effective Models and Lattice QCD

    Francisco X. Azeredo🇧🇷 · Arthur E. B. Pasqualotto🇧🇷 · Bruno S. Lopes🇧🇷 · Dyana C. Duarte🇧🇷 · Ricardo L. S. Farias🇧🇷

    In this work, we discuss recent results obtained with the application of the medium separation scheme (MSS) in different contexts where a clear violation of the conformal limit for the speed of sound at finite density has been observed in Quantum Chromodynamics (QCD). We analyze several scenarios, including QCD at finite isospin density, two-color QCD, and two-flavor color superconductivity. Whenever possible, we compare our findings with lattice QCD (LQCD) results, showing that the Nambu--Jona-Lasinio (NJL) model combined with the MSS provides a consistent description across different regimes of the QCD phase diagram. Our analysis highlights how effective models, when properly regularized, can capture essential nonperturbative features of dense QCD matter, offering complementary insights to lattice simulations.

    hep-phhep-lathep-thnucl-thSymmetry(2026)·7 citations
19. 19*

    A POWHEG generator for di-jet production in polarized proton-proton collisions

    Ignacio Borsa🇩🇪 · David Betz🇩🇪 · Barbara Jäger🇩🇪

    We present a new Monte-Carlo generator for the simulation of di-jet production in polarized proton-proton collisions at the next-to-leading order in QCD matched to parton showers using the framework of the POWHEG BOX. With this program we compute a variety of observables of immediate relevance for the spin program of the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. While parton-shower effects are generally small, we find that in some search regions their inclusion improves agreement of predictions with data. Moreover, we provide a critical assessment of selection criteria applied in experiment in the light of perturbative stability.

    hep-phEPJC(2026)·0 citations
20. 20*

    Dark Matter Heating of Compact Stars Beyond Capture: A Relativistic Framework for Energy Deposition by Particle Beams

    Jaime Hoefken Zink🇵🇱 · Shihwen Hor🇨🇳 · Maura E. Ramirez-Quezada🇩🇪

    Compact astrophysical objects, such as neutron stars and white dwarfs, can act as detectors of energetic particle fluxes originating from astrophysical accelerators. While most existing capture and heating calculations assume isotropic very low energetic incident fluxes from the halo dark matter, many realistic sources produce highly directional beams or jets, for which gravitational focusing, trajectory multiplicity, and local energy deposition must be treated consistently. In this work, we develop a general relativistic formalism to compute the local density, capture probability, and energy deposition of particles arriving as directed beams onto compact objects. The framework is based on the mapping of an asymptotic particle flux to local densities through geodesic congruences, allowing for gravitational focusing, multi-stream regions, and optical depth effects to be incorporated in a unified way. The formalism applies to arbitrary particle species and interaction models, and separates capture from through-going energy deposition in a frame-consistent manner. As an explicit application, we consider relativistic particle beams generated in astrophysical jets and evaluate their interaction with two compact objects samples: a white dwarf and a neutron star. In particular, we illustrate the framework using boosted dark matter produced in a list of 324 blazars as a representative case study, computing the resulting fluxes and the associated heating in the selected stars. Additional regimes such as the interaction roof and geometric limit are discussed, highlighting the conditions under which compact objects can efficiently convert incident beam energy into observable heating.

    hep-phastro-ph.HEJHEP(2026)·0 citations
21. 21*

    Scalar Tsunamis from Black Hole Formation

    Arturo de Giorgi🇬🇧 · Yeray Garcia del Castillo🇦🇺 · Joerg Jaeckel🇩🇪

    Stars and other macroscopic objects may be surrounded by potentially large field configurations of very light scalars coupled to ordinary matter. If the star ends in a black hole, e.g. via a supernova or a neutron star merger, the source vanishes, and the field is released. In this paper, we improve on previous estimates for the field configurations arriving at large distances by including the effects of general relativity and an improved modelling of the initial field configurations. The total amount of energy released is typically of the same order of magnitude as suggested by simple flat space estimates. The spectrum receives noticeable corrections.

    hep-phastro-ph.COgr-qchep-ex+11 citation
22. 22*

    Influence of spatial curvature in cosmological particle production

    Jose A. R. Cembranos🇪🇸 · Luis J. Garay🇪🇸 · Álvaro Parra-López🇪🇸

    We analyze cosmological particle production driven by spacetime expansion in the early universe for homogeneous and isotropic cosmologies with positive, negative, and zero spatial curvature. We prioritize analytical results to gain a deeper understanding of curvature-induced effects. Specifically, for a conformally coupled scalar field, we model the inflationary epoch as an exact de Sitter phase followed by a transition to a static universe. Both instantaneous and smooth exits from inflation are considered, the latter being implemented via the adiabatic vacuum prescription. Starting from an initial Bunch-Davies vacuum, we derive the associated mode functions carefully adapted to each curvature sign. Using the Bogoliubov formalism, we non-perturbatively compute the number density of produced scalar particles. Our results demonstrate that spatial curvature significantly impacts the resulting particle spectra, particularly for light fields, where the deviation from the flat-space scenario is most prominent and can reach several orders of magnitude

    ↳ gr-qchep-phhep-thJCAP(2026)·1 citation
23. 23*

    Neglecting correlations leads to misestimated model errors in EFT predictions

    Nathan L. Carter · Richard J. Furnstahl🇺🇸 · Jordan A. Melendez🇺🇸 · Daniel R. Phillips🇺🇸

    Bayesian analyses of the convergence pattern of Effective Field Theories (EFTs) enable estimation of the uncertainty induced by a truncated expansion. When an EFT that has been calibrated to data is used to make a prediction this truncation uncertainty enters the posterior predictive distribution twice: directly from the finite-order calculation of the predicted quantity and indirectly through the posterior probability distributions of the EFT low-energy constants (LECs) determined by the calibration. In this work, we focus on the interplay of these two sources of uncertainty. We do this in the context of a toy EFT that we fit to pseudodata and use to make predictions. Direct EFT truncation uncertainty and LEC uncertainty are correlated in predictions when the predicted quantity is correlated with the observables used to fit the LECs. Here this results in the overall theoretical uncertainty in the EFT prediction being smaller than either the uncertainty induced by the truncation error or that stemming from the LECs alone.

    ↳ nucl-thhep-phnucl-ex1 citation
24. 24*

    Bound States in Lee's Complex Ghost Model

    Ichiro Oda🇯🇵

    Quantum field theories (QFTs) including fourth derivative terms such as the Lee-Wick finite QED and quadratic gravity have a better ultra-violet behavior compared to standard theories with second derivative ones, but the existence of ghost with negative norm endangers unitarity. Such a ghost in general acquires a pair of complex conjugate masses from radiative corrections whose features are concisely described by the so-called Lee model. Working with the canonical operator formalism of QFTs, we investigate the issue of bound states in the Lee model. We find that the bound states can be created from ghosts as in path integral approach although there is a nontrivial complex delta function, which is a complex generalization of the well-known Dirac delta function. Finally, the problem of amelioration of the unitarity in quadratic gravity is briefly discussed.

    ↳ hep-thgr-qchep-ph5 citations
25. 25*

    Detecting gravitational wave background with equivalent configurations in the network of space based optical lattice clocks

    Mingzhi Lou🇨🇳 · Hong Su🇨🇳 · Tao Yang🇨🇳 · Yun-Long Zhang🇨🇳

    This paper studies the use of optical lattice clock (OLC) detector networks for detecting the stochastic gravitational-wave background (SGWB). Starting from the cross-correlation formalism for two OLC detectors, we analyze how the detector geometry influences the overlap reduction function (ORF) and systematically search for configuration transformations that preserve the modulus of the ORF. We identify an equivalent transformation in which the emitting and receiving ends of both OLC links are exchanged, while the modulus of the ORF remains invariant. We then numerically compare the ORFs of isosceles trapezoidal configurations with different separations and included angles. Based on these results, we design a feasible four-spacecraft orbital configuration and evaluate its strain sensitivity and noise energy-density spectrum in comparison with LISA, Taiji, and TianQin.

    ↳ gr-qcastro-ph.COastro-ph.IMhep-ph+1SCPMA(2026)·0 citations
26. 26*

    Quantum Simulation of Bound and Resonant Doubly-Bottom Tetraquark

    Ayanendu Dutta🇮🇳

    We present the first quantum-simulation study of bound and resonant doubly-bottom tetraquark states within a QCD-inspired chiral quark model. An effective four-quark Hamiltonian is mapped onto a 16-qubit register, encoding color, spin, and spatial degrees of freedom, and incorporating both meson-meson and diquark-antidiquark configurations with complete color bases. Using a variational quantum eigensolver, we identify bound and resonance states in the low-lying $S$-wave sector. Deeply bound states are found exclusively in the isoscalar $I(J^P)=0(1^{+})$ channel, dominated by color-singlet meson-meson components with non-negligible hidden-color contributions. The resulting masses and binding energies are consistent with classical chiral quark model predictions, establishing quantum simulation as a viable framework for studying exotic multiquark states beyond the reach of conventional methods.

    ↳ hep-lathep-phquant-ph0 citations
27. 27*

    Does Cosmology require Hermiticity in Quantum Mechanics?

    Oem Trivedi🇺🇸 · Alfredo Gurrola🇺🇸

    We explore the consequences of allowing non-Hermitian structures in quantum cosmology by extending the Wheeler DeWitt framework beyond strictly Hermitian dynamics. Using a controlled semiclassical reduction, we show how anti Hermitian contributions propagate into both early universe primordial fluctuations and late-time structure growth as effective damping or gain terms. Confronting this framework with inflationary observables, growth of structure and the observed near flatness of the universe, we derive strong infrared constraints that suppress non Hermiticity across cosmic history. We demonstrate that these bounds are mutually consistent between early and late-time probes and can be partially relaxed in theories beyond General Relativity. Our results establish cosmology as a novel arena for testing foundational aspects of quantum mechanics and suggest that Hermiticity may emerge dynamically along the semiclassical branch describing our universe.

    ↳ astro-ph.COgr-qchep-phhep-th+1PLB(2026)·1 citation
28. 28*

    Fixed-energy inverse scattering with radial basis function neural networks and its application to neutron-alpha interactions

    Gábor Balassa🇰🇷

    This paper proposes a data-driven method to solve the fixed-energy inverse scattering problem for radially symmetric potentials using radial basis function (RBF) neural networks in an open-loop control system. The method estimates the scattering potentials in the Fourier domain by training an appropriate number of RBF networks, while the control step is carried out in the coordinate space by using the measured phase shifts as control parameters. The system is trained by both finite and singular input potentials and is capable of modeling a great variety of scattering events. The method is applied to neutron-alpha scattering at 10 MeV incident neutron energy, where the underlying central part of the potential is estimated by using the measured l = 0, 1, 2 phase shifts as inputs. The obtained potential is physically sensible, and the recalculated phase shifts are within a few percent relative error.

    ↳ nucl-thhep-phPTEP(2023)·6 citations
29. 29*

    Consistency of standard cosmologies using Bayesian model comparison and tension quantification

    Lukas Tobias Hergt🇫🇷 · Sophie Henrot-Versillé🇫🇷 · Matthieu Tristram🇫🇷 · Douglas Scott🇨🇦

    We present a unified Bayesian assessment of model comparison and data-set consistency for LCDM (cold dark matter plus a cosmological constant) and minimal extensions (neutrino mass, spatial curvature, constant or evolving dark energy) using cosmic microwave background (CMB), baryon acoustic oscillation (BAO), and type Ia supernova (SN) data. The major results are summarized in the first three figures. We quantify model preference with Bayesian evidence and assess consistency with complementary evidence- and likelihood-based diagnostics applied uniformly across data-set combinations. For the models considered, updated Planck processing systematically improves internal CMB consistency (low-$\ell$ versus high-$\ell$, and primary CMB versus CMB lensing). The preference for a closed geometry and an associated ``curvature tension'' with BAO and/or CMB lensing are largely confined to earlier Planck likelihood implementations and weaken substantially when using updated CMB processing and more recent BAO measurements. Apparent evidence for evolving dark energy in CMB+BAO+SN combinations depends sensitively on the specific pairing of CMB and SN likelihoods: plausible alternatives shift inferred tensions by more than $1\sigma$ and can completely reverse the preferred model. Allowing a free neutrino mass tends to absorb residual shifts without introducing new inconsistencies, and we do not find robust evidence for a standalone $\tau$-driven discrepancy once the full likelihood context is accounted for. We conclude that claims of a required update of our standard cosmological model from LCDM to $w_0{w}_a$CDM are premature.

    ↳ astro-ph.COastro-ph.GAgr-qchep-ph+17 citations
30. 30*

    Searching for dark matter signals with high energy astrophysical neutrinos in IceCube

    Khushboo Dixit🇿🇦 · Gopolang Mohlabeng🇨🇦 · Soebur Razzaque🇿🇦

    High-energy neutrinos provide a potentially powerful and distinctive probe for dark matter (DM) - neutrino interactions, particularly in environments with enhanced DM densities, such as the DM spikes predicted to form around supermassive black holes (SMBHs) at the center of active galactic nuclei (AGN). Recent results by the IceCube Neutrino Observatory, which reported four significant AGNs, namely TXS 0506+056, NGC 1068, PKS 1424+240, and NGC 4151 as candidate neutrino sources, provide a valuable opportunity to search for signatures of these interactions. In this study, we use IceCube data to derive the most stringent constraints to date on both the energy-dependent and energy-independent DM-neutrino scattering cross-sections. We perform a statistical analysis using data from individual sources as well as a combined (stacked) analysis of all four sources. Our strongest limits arise from the stacking analysis, yielding an upper bound of ${\sigma }_0\lesssim 8\times 10^{-39}$ cm${}^2$ for an energy-independent cross-section and ${\sigma }_0\lesssim 10^{-39}$ cm${}^2$ for a linearly energy-dependent cross-section, both at 90$\%$ confidence level, particularly in scenarios involving the adiabatic growth of black holes.

    ↳ astro-ph.HEhep-phPRD(2026)·2 citations

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