Fri·Jan 23, 2026Friday·January 23, 2026

1. 01*

   Structure functions for the inclusive semileptonic $b$-quark decay at NNLO: a semi-analytic calculation

   A. Broggio🇦🇹 · B. Capdevila🇪🇸 · A. Ferroglia🇺🇸 · P. Gambino🇮🇹

   We present a study of the inclusive charmless semileptonic $b$ decay, $b\to X_u\ell \bar{\nu }$ at next-to-next-to-leading order (NNLO) in perturbative QCD, with the primary aim of extracting the hadronic structure functions $W_i$ at NNLO. The analysis is based on a numerical calculation of the relevant kinematic distributions using a phase-space slicing method to handle infrared-sensitive contributions from real gluon emissions. We use known results from Heavy Quark Effective Theory and Soft-Collinear Effective Theory to extract the singular terms and construct a model for the regular contributions to the structure functions at NNLO, then perform a fit to the numerical results. We use our approximate structure functions to compute various kinematic distributions and moments: the comparison with existing analytic and numerical results shows very good agreement, which is further improved including the available analytic results in the fit.

   hep-phJHEP(2026)·5 citations
2. 02*

   LHC Signatures of Neutral Scalar Cascades in the $Z_3$ symmetric 3HDM

   Baradhwaj Coleppa🇮🇳 · Akshat Khanna🇮🇳 · Santosh Kumar Rai🇮🇳 · Agnivo Sarkar🇮🇳

   Extending the scalar sector is one of the standard approaches to exploring scenarios beyond the Standard Model. In this work, we examine the collider phenomenology of the Three Higgs Doublet Model (3HDM) in the Type-Z or the democratic Yukawa interaction setup at the LHC. The scalar spectrum of the 3HDM includes three CP-even scalars, two CP-odd scalars, and four charged Higgs bosons. Focusing on cascade decay topologies, we investigate the collider signatures of the neutral scalars through the process $pp\to SV$, where $S$ is a neutral scalar and $V$ is a vector boson. We perform a cross-section analysis across multiple benchmark points that satisfy both theoretical and experimental constraints, considering two mass hierarchy scenarios: (i) Regular Hierarchy, where the SM-like Higgs is the lightest CP-even scalar, and (ii) Medial Hierarchy, featuring one Higgs boson lighter than the SM Higgs and one heavier. For both scenarios, we study the specific process $pp\to A\to HZ\to b\bar{b}{l}^{+}{l}^{-}$, performing a cut and count analysis at $\sqrt{s}=14$ TeV. Our results demonstrate that while the Medial Hierarchy scenario allows discovery-level sensitivity for both the CP-even and CP-odd scalars, achieving the same sensitivity in the Regular Hierarchy setup necessitates substantially higher luminosity.

   hep-ph2 citations
3. 03*

   Excluding Local Hidden Variables in $\Lambda \bar{\Lambda }$ Production: The Incompatibility with Angular-Momentum Conservation and CPT Invariance

   Junle Pei🇨🇳 · Lina Wu🇨🇳 · Tianjun Li🇨🇳 · Xiqing Hao🇨🇳

   We analyze spin entanglement in $\Lambda \bar{\Lambda }$ pairs produced in the decays of spin-zero particles, contrasting predictions from quantum field theory (QFT) with those of local hidden-variable theories (LHVTs). Using the self-analyzing weak decays $\Lambda \to p{\pi }^{-}$ and $\bar{\Lambda }\to \bar{p}{\pi }^{+}$, we derive the joint angular distributions within QFT. Our key findings are: For scalar production $h\to \Lambda \bar{\Lambda }$, no LHVT respecting locality and angular-momentum conservation can reproduce the QFT distribution. For pseudoscalar production $a\to \Lambda \bar{\Lambda }$, a CPT-symmetric LHVT is excluded by positivity constraints given the measured analyzing powers; however, if CPT symmetry is relaxed, an explicit LHVT construction -- with uniform hidden-variable measure and response functions satisfying $b_1{c}_1=3{\alpha }_{\Lambda }{\alpha }_{\bar{\Lambda }}$ -- can match the QFT result. For the most general spin-zero decay $s\to \Lambda \bar{\Lambda }$ with arbitrary scalar-pseudoscalar mixing, we, under CPT invariance, identify the regions of parameter space where the QFT joint angular distribution does or does not admit an LHVT realization. These distinct signatures provide clear, experimentally testable criteria to discriminate between QFT and LHVT in $\Lambda \bar{\Lambda }$ systems across different production mechanisms.

   hep-phJHEP(2026)·9 citations
4. 04*

   Unveiling a Universal Formalism for Quantum Entanglement in Arbitrary Spin Decays

   Junle Pei🇨🇳 · Lina Wu🇨🇳 · Dianwei Wang🇨🇳 · Xiqing Hao🇨🇳 · Tianjun Li🇨🇳

   We present a comprehensive theoretical framework for probing quantum entanglement in the decay angular distributions of a spin-$S$ particle-antiparticle pair $A\bar{A}$, where each particle decays sequentially into a two-body final state, $A\to B+C$ and $\bar{A}\to \bar{B}+\bar{C}$, with $B(\bar{B})$ carrying spin $b$ and $C(\bar{C})$ being spinless. Starting from the most general polarized initial state, we derive the fully differential angular distribution $\mathcal{W}({\theta }_1,{\theta }_2,{\varphi }_1,{\varphi }_2)$ and identify observables $⟨\cos (2S({\varphi }_1\mp {\varphi }_2))⟩$ whose expectation values directly depend on the entanglement-sensitive coefficients $\text{Re}\left({\alpha }_{-S,\mp S}{\alpha }_{S,\pm S}^{\ast }\right)$ of the initial state. The proportionality factor $\mathcal{C}(S,b)$ in these relations is computed explicitly. For bosonic decays ($b=0,1,2,\dots$), $\mathcal{C}(S,b)$ is universal and independent of decay dynamics; in particular, $\mathcal{C}(S,0)=1/2$ for any $S$, and $\mathcal{C}(1,1)=1/8$, matching known results for $W^{+}{W}^{-}$ decays. For fermionic decays ($b=\frac{1}{2},\frac{3}{2},\frac{5}{2}\dots$), $\mathcal{C}(S,b)$ depends explicitly on the spin analysis powers ${\alpha }_{A/\bar{A}}$, making entanglement extraction more decay-dependent. We further demonstrate, within the context of $e^{+}{e}^{-}\to {\gamma }^{\ast }\to A\bar{A}$ production, how ${\alpha }_{A/\bar{A}}$ can be determined experimentally using specific angular observables restricted to the beam-axis region. Our results highlight the special role of bosonic decays in providing clean, model-independent tests of quantum entanglement at colliders, while outlining a pathway for entanglement measurement in fermionic cases through supplementary polarization information.

   hep-ph7 citations
5. 05*

   Two-loop rainbow neutrino masses in a non-invertible symmetry

   Hiroshi Okada🇨🇳 · Yoshihiro Shigekami🇨🇳

   We propose two-loop rainbow type of the neutrino mass model via $Z_2$ gauging of $Z_6$ non-invertible symmetry in which we introduce three families of isospin doublet vector-like fermions, heavy right-handed neutrinos and isospin doublet and singlet bosons. All new fields, which have nonzero charges under the non-invertible symmetry, can be dark matter candidates, since the non-invertible symmetry possesses a remnant $Z_2$ symmetry that plays a role in assuring the stability of our dark matter candidate. Even though the non-invertible symmetry is dynamically broken at one-loop level, its violation does not affect our scenario. In this paper, we especially consider the lightest mode of the neutral components in the doublet vector-like fermions as our main dark matter candidate. The dark matter is potentially degenerated to the other two families of neutral fermions, since the mass difference is induced at one-loop level. Thus, we consider our dark matter candidate in rather simpler co-annihilation system among their particles. Considering all the constraints of neutrino oscillation data, lepton flavor violations, muon $g-2$ and the relic density of dark matter, we perform the numerical analysis and show some allowed regions for these phenomenology. Due to our dark matter nature, the sum of neutrino masses in case of normal hierarchy is larger than that in case of inverted hierarchy, which is opposite situation compared with typical active neutrino models.

   hep-ph5 citations
6. 06*

   Decay Effect on Near-Threshold Mass Scaling with Complex and Coupled-Channel Potentials

   Erick Gushiken🇯🇵 · Tetsuo Hyodo🇯🇵

   We investigate the effect of decay channels on the near-threshold mass scaling by employing potential models. By varying the attractive strength of a square-well potential, we examine the pole trajectory associated with the transition of an $s$-wave bound state into a resonance state, incorporating decay-channel effects through both a single-channel complex potential model and a coupled-channel real potential model. As a result, we show that the pole of a quasibound state below the threshold is not continuously connected to that of a resonance state above the threshold. Furthermore, by comparing the results obtained from the single-channel and coupled-channel models, we clarify the correspondence between the pole trajectories in the two approaches.

   hep-phnucl-th0 citations
7. 07*

   Interplay between the chiral and deconfinement transitions from a Curci-Ferrari-based Polyakov loop potential

   V. Tomas Mari Surkau🇫🇷 · Urko Reinosa🇫🇷

   We couple the two-flavor Nambu--Jona-Lasinio model to a gluonic background corresponding to the gauge-field expectation value in the center-symmetric Landau gauge. Low-energy features in this gauge are captured by a center-symmetric extension of the Curci-Ferrari model and provide a good grasp on key aspects of the confinement/deconfinement transition. Within this framework, we can investigate the interplay between the chiral and deconfinement transitions. Compared to other approaches based on multi-parameter Ansätze of the Polyakov loop potential fixed from comparison to finite-temperature lattice data, the modeling of the glue sector in the present set-up depends on only one phenomenological parameter that can be fixed by comparison to lattice data in the vacuum. We detail the structure of the phase diagram, with special emphasis on the finite density axis, and compute thermodynamical observables relevant for applications. We also highlight the properties of the recently introduced net quark number response of the medium as a sensible probe of the phases of QCD, in particular as a tool to disambiguate the nature of certain regions of the phase diagram where the use of the Polyakov loops could lead to misinterpretations. Finally, we critically assess the sensitivity of our results to the various parameters, both in the glue sector and in the chiral sector.

   hep-phhep-th3 citations
8. 08*

   WIMP Dark Matter from a Natural Discrete Gauge Symmetry in the Standard Model

   Jie Sheng🇯🇵 · Tsutomu T. Yanagida🇯🇵 · Kairui Zhang🇺🇸

   The internal structure of the Standard Model implies a natural ${\mathbb{Z}}_4\times {\mathbb{Z}}_3$ discrete gauge symmetry. Cancellation of the corresponding Dai--Freed anomalies requires the introduction of three right-handed neutrinos and three additional Majorana fermions ${\chi }_i$. This gauge symmetry forbids the decay of the lightest fermion ${\chi }_1$ into Standard Model particles, rendering it automatically stable and providing a dark matter candidate without introducing an ad hoc stabilizing symmetry and domain-wall problem. The mass of ${\chi }_1$ is generated by the vacuum expectation value of a singlet scalar near the electroweak scale, naturally realizing a weakly interacting massive particle (WIMP) freeze-out scenario. Dark matter annihilation proceeds through scalar mediation, allowing the observed relic abundance to be reproduced while remaining consistent with current direct-detection constraints. It naturally realizes the secluded dark matter scenario and can be further tested in the next generation of experiments.

   hep-phJHEP(2026)·4 citations
9. 09*

   Threshold corrections in SMEFT

   Anke Biekötter🇩🇪 · Livia E. G. Maskos🇬🇧 · Benjamin D. Pecjak🇬🇧

   Threshold corrections provide a universal link between experimentally measured broken-phase parameters and $\overline{MS}$ renormalised symmetric-phase parameters used in SMEFT renormalisation-group (RG) analyses and matching to new-physics models. In this work we compute in analytic form the complete set of one-loop threshold corrections in dimension-six SMEFT, using two electroweak input schemes and including tadpole effects in the Fleischer-Jegerlehner (FJ) scheme. As a by-product of the analysis, we obtain the full one-loop running of the strong coupling in SMEFT, including electroweak corrections, and the associated decoupling constants when the top quark and heavy electroweak bosons are integrated out. Although generally moderate, the loop-level dimension-six corrections can be enhanced through tadpole effects and top-quark loops, and can shift symmetric phase parameters at the 5% level under reasonable assumptions. Our results constitute a process-independent ingredient which can be readily implemented in public RG-running and matching codes in SMEFT.

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

    Neutrino-Induced Polarization Rotation in Active Galactic Nuclei Plasmas

    H. B. Câmara🇵🇹 · A. Smetana🇨🇿 · A. A. Tursunov🇨🇿

    We study parity-violating birefringence induced by an asymmetric neutrino background in plasmas associated with active galactic nuclei (AGN). We derive a directionality factor arising from the relative bulk motion between the neutrino medium and plasma, and show that it can produce an anomalous frequency dependence of the polarization-rotation angle, distinct from the ${\omega }^{-2}$ scaling of Faraday rotation. This anomalous scaling can occur either at the resonance plasma frequency condition $\omega \simeq {\omega }_p$, or when $E_{\nu }^0\simeq m_{\nu }\omega /{\omega }_p$ lies within the range of the neutrino energy spectrum. We estimate the effect for three scenarios: jets propagating through the cosmic neutrino background (C$\nu$B), jets with an internal flux of high-energy neutrinos, and accretion-disk plasma permeated by the C$\nu$B. Of the three scenarios, the latter gives the largest rotation angle ${\varphi }_{\mathrm{d}}\sim 10^{-35}\mathrm{rad}$, at X-ray frequencies. Although the predicted rotation angles are below current polarimetric sensitivity, the identified spectral signatures provide a theoretical framework for probing neutrino asymmetries and AGN plasma properties independent of magnetic field models.

    hep-phastro-ph.HEPRD(2026)·0 citations
11. 11*

    Dominant Thermal Resonant Mechanism for Low-Scale Leptogenesis

    Shao-Ping Li🇯🇵 · Apostolos Pilaftsis🇬🇧

    We explicitly demonstrate the importance of a new thermal resonant channel in the context of low-scale leptogenesis, which goes beyond the well-known mixing and oscillation of massive singlet neutrinos. This new channel is always present when considering the thermally-induced Higgs decay to leptons and relativistic singlet neutrinos, and can become dominant thanks to thermally-generated resonant lepton-doublet flavour coherences. This mechanism, which we call Thermal Resonant Leptogenesis (TRL), can yield the observed baryon asymmetry in our universe, even if there is no resonant enhancement from quasi-degenerate sterile neutrinos. The required active-to-sterile neutrino mixing for TRL differs from other known low-scale leptogenesis scenarios and can be probed in fixed-target and long-lived particle experiments, and by displaced vertex searches at high-energy colliders.

    hep-ph1 citation
12. 12*

    Gravitational Wave Signature of Aspherical Bubbles Driven by Thermal Fluctuation

    Ligong Bian🇨🇳 · Guangshang Chen🇨🇳 · Song Li🇨🇳 · Hongxin Wang🇨🇳 · Yang Xiao🇨🇳 · Jin Min Yang🇨🇳 · Yang Zhang🇨🇳

    Cosmological first-order phase transitions are a well-motivated source of stochastic gravitational waves (GWs), but most predictions are made based on the highly idealized model of perfectly spherical vacuum bubbles, neglecting thermal fluctuations. In this work we use $(3+1)$-dimensional lattice simulations of a scalar model with thermal initial conditions to quantify how thermal fluctuations distort bubble profiles and modify the resulting GW spectrum. We find that thermal fluctuations can strongly break spherical symmetry at early times, allowing even an isolated bubble to emit GWs. In multi-bubble simulations, thermal fluctuations systematically reshape the spectrum, suppressing the infrared part while enhancing and broadening the high-$k$ tail. We further provide an analytical estimate for the ultraviolet regime of the GW spectrum, which is in good agreement with our lattice results and suggests that this regime is dominated by thermal fluctuations. These effects could leave observable imprints in future GW searches.

    hep-phgr-qc2 citations
13. 13*

    Radiative corrections to decays of the 125 GeV Higgs boson in the complex Higgs triplet model

    Masashi Aiko🇯🇵 · Shinya Kanemura🇯🇵 · Mariko Kikuchi🇯🇵 · Kodai Sakurai🇯🇵 · Sora Taniguchi🇯🇵 · Kei Yagyu🇯🇵

    The extension of the Higgs sector with an additional complex triplet field is often considered for generating the neutrino mass by the Type-II seesaw mechanism. Such an extension generally predicts $\rho \ne 1$, where $\rho$ is the electroweak rho parameter at the tree level, so that the renormalization of the electroweak parameters is different from models like the standard model (SM) and two Higgs doublet models. In this paper, we present a full set of radiative corrections to decays of the 125 GeV Higgs boson ($h$) in this model. One-loop contributions of the extra Higgs bosons as well as SM fermions and gauge bosons to the decay rates of $h$ are calculated in the on-shell scheme. Gauge dependence appearing in the counter terms of mixing angles is eliminated by the pinch technique. Higher-order QCD corrections are also implemented. We find that the decay rates can significantly deviate from the predictions in the SM and other extensions such as the two Higgs doublet models and the singlet model. For example, the decay rates of $h\to W{W}^{\ast }$ and $h\to Z{Z}^{\ast }$ can be a few percent larger than the SM value under current experimental and theoretical constraints. In this case, deviations in $h\to \gamma \gamma$ and Higgs self-coupling can reach about $-20\%$ and $100\%$, respectively. The pattern of the deviations is different from the other extended Higgs models. These characteristic predictions are expected to be detected at the High-Luminosity LHC or future Higgs factories.

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

    Photon-dark photon oscillation in M87 and Crab Nebula environments

    Tanmay Kumar Poddar🇬🇧 · Sourov Roy🇮🇳 · Pratick Sarkar🇮🇳

    Compact astrophysical systems such as neutron stars and black holes provide powerful laboratories for testing feebly coupled dark photons (DPs). We investigate light DPs kinetically mixed with the visible photon that need not be the dark matter, focusing on resonant photon-DP oscillations in magnetized, modeled plasma environments. We show that realistic non-monotonic plasma density profiles generically enhance resonant conversion relative to monotonic models, leading to substantially stronger constraints on the photon-DP kinetic mixing parameter ($ϵ$). Using spectral data from the supermassive black hole (SMBH) M87*, extending to the LOFAR band, we derive a bound $ϵ\simeq 7\times 10^{-6}$ at the DP mass $m_{A^{\prime }}\simeq 5\times 10^{-7}\mathrm{eV}$ for oscillation distance $3r_{\mathrm{ph}}$, where $r_{\mathrm{ph}}$ denotes the photon sphere radius. From the Crab pulsar-wind Nebula, we obtain an even stronger constraint, $ϵ\simeq 8\times 10^{-7}$ at $m_{A^{\prime }}\simeq 4\times 10^{-9}\mathrm{eV}$ for oscillation baselines of order $10^3\mathrm{km}$, surpassing existing astrophysical limits in realistic plasma backgrounds. While laboratory and cosmological bounds remain slightly stronger at comparable masses, observation of compact objects with larger surface magnetic fields and measurements of photon spectra at lower frequencies would enhance the limits on the photon-DP coupling by orders of magnitude.

    hep-phastro-ph.HE3 citations
15. 15*

    Quark-lepton correlations in gauge anomaly free abelian extension of the Standard Model

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

    We study $b\to s{\ell }_1^{+}{\ell }_2^{-}$ transitions, both for the lepton flavour conserving ${\ell }_1={\ell }_2$ and violating case ${\ell }_1\ne {\ell }_2$, in a minimal extension of the Standard Model proposed in [1]. In this framework, the Standard Model (SM) gauge group is enlarged by a new $U(1{)}^{\prime }$ component. The fermion $U(1{)}^{\prime }$ charges are assigned in a generation-dependent way, and involve three rational parameters ${ϵ}_{1,2,3}$ summing to zero by the condition of cancellation of the gauge anomalies. Each ${ϵ}_i$ is common to all fermions in a generation, which produces correlations among quark and lepton observables. The new neutral gauge boson $Z^{\prime }$ has flavour violating couplings to quarks and leptons. For SM allowed processes, small deviations with respect to the SM predictions are found: this is a consequence of a feature of the model where quark and lepton sectors preclude each other large deviations from SM. Lepton flavour violating processes are allowed at tree-level. The experimental upper bounds for the rates of the processes ${\tau }^{-}\to {\mu }^{-}{\mu }^{+}{\mu }^{-}$, ${\mu }^{-}\to e^{-}\gamma$, ${\mu }^{-}\to e^{-}{e}^{+}{e}^{-}$ and the ${\mu }^{-}\to e^{-}$ conversion in nuclei play a hierarchical role in constraining the branching fractions of lepton flavour violating $B$ and $B_s$ decays.

    hep-phhep-exhep-latPoS(2026)·0 citations
16. 16*

    Carrier-envelope phase and pulse shape effects on vacuum pair production in asymmetric electric fields with bell-shaped envelopes

    Abhinav Jangir🇮🇳 · Anees Ahmed🇮🇳

    We investigate the combined effects of carrier-envelope phase and laser pulse shape on electron-positron pair production in the presence of an external time-dependent asymmetric electric field by solving the quantum Vlasov equation. We analyze how the pulse asymmetry, the envelope type (Gaussian, Lorentzian and Sauter), and the carrier-envelope phase jointly influence the momentum distribution and the total number of produced pairs per unit volume. Our results show that pair production exhibits extreme sensitivity to both the degree of temporal asymmetry and the steepness of the envelope on either side of the pulse. These effects are qualitatively explained through a turning-point analysis for the non-analytic electric field using a regularization scheme. We observe that multiphoton pair production dominates the Schwinger mechanism in the case of a long falling-pulse asymmetry. For a short falling pulse with a flat-topped profile, pair production is further facilitated. We demonstrate that the density of produced pairs can be enhanced by two to three orders of magnitude by choosing certain field parameters.

    hep-phhep-thPRD(2026)·1 citation
17. 17*

    One-Loop QCD Corrections to $\bar{B}\to X_c\ell {\bar{\nu }}_{\ell }$ in and Beyond the Standard Model

    Alexandre Carvunis🇩🇪 · Gael Finauri🇮🇹

    We compute one-loop QCD corrections to the triple differential width of the inclusive decay $\bar{B}\to X_c\ell {\bar{\nu }}_{\ell }$ including contributions from all relevant dimension-six operators in the Weak Effective Theory (WET), at leading power in heavy quark expansion. Furthermore we derive for the first time up to order $\mathcal{O}({\alpha }_s)$ analytic expressions for the first three moments of the distribution in the lepton energy, hadronic invariant mass and dilepton invariant mass, in the presence of beyond the Standard Model contributions from the WET.

    hep-phJHEP(2026)·1 citation
18. 18*

    Searching for Ultralight Scalar Dark Matter with Clocks in Low Earth Orbit

    Dawid Brzeminski🇺🇸 · Aaron Pierce🇺🇸

    The density of ultralight dark matter can be modified in the vicinity of macroscopic bodies when the dark matter possesses quadratic couplings to the Standard Model. If these couplings are sufficiently strong, Earth's atmosphere acts to shield the dark matter, thereby limiting the effectiveness of laboratory-based experiments. Experiments performed at altitudes exceeding the dark matter de Broglie wavelength experience the same orbit-averaged field amplitude as in the absence of scattering. Quantum clocks are capable of detecting variations in fundamental parameters due to the dark matter background. If based on the International Space Station, they are therefore well-suited to probe dark matter masses $m_{\mathrm{DM}}\gtrsim 10^{-9}\text{ eV}$. Moreover, when the dark matter de Broglie wavelength is smaller than Earth's radius ($m_{\mathrm{DM}}\gtrsim 10^{-10}$ eV), the dark matter profile around Earth exhibits a dipole feature. In Low Earth Orbits this dipole temporally modulates potential dark matter signals. This provides a powerful cross-check of the orbit-averaged effect and can enhance the sensitivity of these experiments. We find optical clocks could give rise to world-leading constraints in some cases. Orbiting nuclear clocks could probe even more of the parameter space inaccessible to ground-based experiments.

    hep-phastro-ph.COJHEP(2026)·5 citations
19. 19*

    Fuzzy dark matter soliton core hosting a supermassive black hole as a dense low-mass perturber in strong gravitational lensing

    Masamune Oguri · Naoi Kubo

    Recent high-resolution imaging observations of strong lens systems reveal dense low-mass perturbers. We propose a soliton core, whose central density is boosted by a supermassive black hole (SMBH), in the fuzzy dark matter (FDM) model as an efficient perturber in strong gravitational lensing. The higher central density makes it less efficient in the tidal mass loss, and leads to the higher impact in gravitational lensing. We show that the mass profile of a $\sim 10^6{M}_{\odot }$ perturber in JVAS B1938+666, which does not resemble any known astronomical object, can be well explained by a soliton core in the FDM model with the mass of $4\times 10^{-21}$eV hosting an SMBH with the mass of $4\times 10^5{M}_{\odot }$. The high mass of the SMBH may be explained by several scenarios that predict heavy SMBH seeds such as the direct collapse black hole formation and primordial black holes.

    ↳ astro-ph.COhep-phJCAP(2026)·2 citations
20. 20*

    Unveiling the spectral morphological division of fast radio bursts with CHIME/FRB Catalog 2

    Wan-Peng Sun🇺🇸 · Yin-Long Cao🇺🇸 · Yong-Kun Zhang🇨🇳 · Ji-Guo Zhang🇺🇸 · Xiaohui Liu🇨🇳 · Yichao Li🇺🇸 · Fu-Wen Zhang🇨🇳 · Wan-Ting Hou🇨🇳 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    Fast radio bursts (FRBs) are commonly classified into repeating and apparently nonrepeating sources, yet whether this distinction reflects intrinsically different physical populations remains uncertain. Using the Second CHIME/FRB Catalog, we apply an unsupervised machine learning framework combining Uniform Manifold Approximation and Projection (UMAP) with density-based clustering to investigate the intrinsic structure of the FRB population in a multi-dimensional parameter space. We find that FRBs are primarily separated into two robust clusters dominated by spectral morphology. One cluster is characterized by narrowband emission and longer durations, while the other exhibits relatively broadband spectra and shorter burst timescales. This classification scheme achieves a recall of 0.94 for known repeaters. Within the repeating population, we further identify a stable subclass of atypical repeaters that are broadband, shorter in duration, and more luminous, resembling nonrepeating bursts. Furthermore, broadband nonrepeaters exhibit systematically higher dispersion measures (by approximately 200 ${\text{pc cm}}^{-3}$) and isotropic luminosities approximately an order of magnitude larger than those of repeating FRBs. Without invoking catastrophic progenitor scenarios, these differences are naturally explained by instrumental sensitivity limits and distance-dependent selection effects. Our results provide new statistical evidence for a physical connection between repeating and nonrepeating FRBs.

    ↳ astro-ph.HEastro-ph.COgr-qchep-ph+1SCPMA(2026)·5 citations
21. 21*

    Reanalyzing DESI DR1: 4. Percent-Level Cosmological Constraints from Combined Probes and Robust Evidence for the Normal Neutrino Mass Hierarchy

    Mikhail M. Ivanov🇺🇸 · James M. Sullivan🇺🇸 · Roger de Belsunce🇺🇸 · Shi-Fan Chen🇺🇸 · Anton Chudaykin🇨🇭 · Mark Maus🇺🇸 · Oliver H. E. Philcox🇺🇸

    We present cosmological parameter measurements from the full combination of DESI DR1 galaxy clustering data, described with large-scale structure effective field theory. By incorporating photometric galaxies and CMB lensing cross-correlations, and extending the bispectrum likelihood to smaller scales with a consistent one-loop computation, we achieve substantial gains in constraining power. Combined with the latest DESI baryon acoustic oscillation (BAO) data and cosmic microwave background (CMB) priors on the spectral tilt and baryon density, we find, in $\Lambda$CDM, $H_0=69.08\pm 0.37\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$, ${\Omega }_m=0.2974\pm 0.0050$, and ${\sigma }_8=0.838\pm 0.017$ ($S_8={\sigma }_8\sqrt{{\Omega }_m/0.3}=0.834\pm 0.018$). Adding the Pantheon+ supernovae (SNe), we find a $2.2\sigma$ preference for the $w_0{w}_a$ dynamical dark energy model from low-redshift data alone, rising to $2.7\sigma$ when exchanging the SNe for \textit{Planck} CMB data. Combining the full-shape, BAO, CMB, and SNe likelihoods improves the dark energy figure-of-merit by $15\%$ and bounds the neutrino mass sum to $M_{\nu }<0.049$ eV ($\Lambda$CDM) and $M_{\nu }<0.077$ eV ($w_0{w}_a$CDM) at 95\% CL. This is the strongest $w_0{w}_a$CDM bound to date, $37\%$ tighter than from the background expansion data alone. The preference for the normal neutrino mass ordering thus holds regardless of the background model: the inverted hierarchy is disfavored at $\approx 3.5\sigma$ in $\Lambda$CDM and $\approx 2.4\sigma$ in $w_0{w}_a$CDM, with the latter constraint free of the geometric tension between CMB and BAO that is known to sharpen the $\Lambda$CDM bound.

    ↳ astro-ph.COhep-exhep-phhep-th25 citations
22. 22*

    Conservative Black Hole Scattering at Fifth Post-Minkowskian and Second Self-Force Order

    Mathias Driesse🇩🇪 · Gustav Uhre Jakobsen🇩🇪 · Gustav Mogull🇩🇪 · Christoph Nega🇩🇪 · Jan Plefka🇩🇪 · Benjamin Sauer🇩🇪 · Johann Usovitsch🇩🇪

    Using the worldline quantum field theory formalism, we compute conservative contributions to the scattering angle and impulse for classical black hole scattering at fifth post-Minkowskian (5PM) and second self-force (2SF) order. This four-loop calculation involves non-planar Feynman integrals and requires advanced integration-by-parts reduction, novel differential-equation strategies, and efficient boundary-integral algorithms to solve a system of hundreds of master integrals in four integral families on high-performance computing systems. The resulting function space includes multiple polylogarithms as well as iterated integrals with a K3 period, which generate a spurious velocity divergence at $v/c=\sqrt{8}/3$, $\gamma =3$. This divergence is present in the potential region and must be canceled by contributions from the radiative memory region, while its dimensional-regularisation pole should cancel against the radiative tail region. As the standard use of Feynman propagators fails to ensure this cancellation, we instead propose a ($\gamma$-3) conservative prescription that realises both cancellations, leading to a physically sensible answer. All available low-velocity checks of our result against the post-Newtonian literature are satisfied.

    ↳ hep-thgr-qchep-phPRL(2026)·36 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.