Mon·Jan 12, 2026Monday·January 12, 2026

1. 01*

   Polarisation fractions in $B\to V_1{V}_2$: U-Spin constraints and new physics signatures

   Debajyoti Choudhury🇮🇳 · Suman Kumbhakar🇮🇳 · Anirban Kundu🇮🇳 · Soumitra Nandi🇮🇳

   We investigate the decays of $B$ mesons, {\em i.e.}, $B_d$, $B_s$, $B^{+}$, and their antiparticles, to two light vector mesons ($B\to V_1{V}_2$). We use the SU(2) U-spin symmetry, which relates $\Delta S=0$ and $\Delta S=1$ decay amplitudes through the interchange $d\leftrightarrow s$ and is an approximate symmetry of the Standard Model (SM), to relate the helicity amplitudes of these decays. Treating all the helicity amplitudes for these decays, and hence the reduced matrix elements, as free parameters, we find an acceptable solution within the SM, although this is driven by the fact that the number of observables is smaller than what is needed for a meaningful fit. To reduce the number of free parameters, we then use some apparently reasonable and theoretically motivated approximations, like the dominance of factorisable contributions over the non-factorisable ones, and hence a distinct hierarchy between the helicity amplitudes. We find that once the assumption of hierarchy is imposed, there is no acceptable solution. This is due to the longitudinal polarisation fractions in almost all $\Delta S=1$ decays. This is particularly true for $B_s\to K^{\ast 0}\overline{K^{\ast 0}}$, for which the individual disagreement with U-spin based expectation is more than $7\sigma$. Within SM, the only effective resolution would be to allow for large nonfactorisable contributions to all these decay amplitudes. We also explore whether some new physics (NP) in the $b\to s$ sector that does not respect the hierarchy among the helicity amplitudes can reduce the tension for all the $\Delta S=1$ modes. While such an option helps, we find that for simplistic new physics scenarios, the tension still exists and the fit remains poor enough, if the hierarchy exists among the SM amplitudes. Some possible scenarios for a complete solution of the puzzle are also suggested.

   hep-phhep-exPRD(2026)·2 citations
2. 02*

   Information-theoretic astrophysical uncertainties in the effective theory of dark matter direct detection

   Gonzalo Herrera🇺🇸

   The impact of astrophysical uncertainties in direct detection searches can vary significantly across particle dark matter models and detector targets, due to the different velocity and momentum dependencies of the scattering cross section. We address these uncertainties for all operators of the non-relativistic effective field theory of dark matter-nucleon interactions, making use of the Kullback-Leibler (KL) information divergence to measure the deviation of the true dark matter velocity distribution from the Maxwell-Boltzmann form. This approach quantifies how astrophysical uncertainties affect each operator in the effective theory, without assuming any specific functional form for the velocity distribution. While for some operators the uncertainties are smaller than one order of magnitude for entropically-motivated deviations from the Maxwell-Boltzmann form, for other operators these uncertainties can be as large as three orders of magnitude near threshold. Furthermore, we identify the dependence of the scattering rate for various operators of the effective theory with different velocity-weighted moments of the velocity distribution, functionally analogous to the mean, variance, or skewness. This provides new analytic insight into which features of the velocity distribution are most relevant to detect a given particle dark matter model. Our technique is general and could be applied to a broader class of physics problems where a physical observable depends on the statistical moments of an uncertain theoretical distribution.

   hep-phastro-ph.COastro-ph.GAhep-exPRD(2026)·1 citation
3. 03*

   Dipole Radiation and Kinetic Mixing from Dark Photon Solitons

   Enrico D. Schiappacasse🇨🇱 · Moira Venegas🇺🇸

   Wave-like dark matter composed of spin-1 particles, known as dark photons, is theorized to form clumps called "vector solitons". These solitons are compact astrophysical objects that exhibit coherent oscillations and a high concentration relative to the local dark matter density. A significant portion of dark matter in galactic halos today may consist of these solitons. This study explores how photons can be produced from these vector solitons by the influence of external electromagnetic fields or charge densities, via a dimension-6 dark photon-photon coupling and a kinetic mixing, respectively. We further explore the astrophysical implications of these phenomena, highlighting a novel avenue for dark matter discovery that our research provides.

   hep-phastro-ph.COastro-ph.HEPRD(2026)·6 citations
4. 04*

   Achieving Full Coverage of the SME Minimal Matter Sector

   Facundo Martin Lopez🇺🇸 · Zhiyu Zhang🇺🇸 · Bianca Rose Lott🇺🇸 · Jay D. Tasson🇺🇸

   Existing experiments and data sets can be leveraged to obtain additional sensitivities to Lorentz violation, beyond those originally sought, through a more precise consideration of the boost of the experiment through the background. In fact, access to the full coefficient space of the flat-spacetime single-fermion limit of the minimal matter sector of the Standard-Model Extension can be obtained. In this work we present this coverage for a sample particle in the context of a simplified model of Earth's motion.

   hep-ph0 citations
5. 05*

   A Penning trap single-photon counter for axion detection

   Jack A. Devlin🇬🇧 · Marko L. Wojtkowiak🇬🇧 · Shreyak R. Banhatti🇬🇧 · He Zhang🇬🇧 · Jiacheng Shi🇬🇧 · Toren S. Dofher🇬🇧 · Jonathan M. H. Gosling🇬🇧 · Michael R. Tarbutt🇬🇧 · Richard C. Thompson🇬🇧

   Discovering the microscopic composition of dark matter is one of the most important open problems in physics today. Axions are a leading candidate to be dark matter; however, a search of the full range of all likely axion masses is hampered by the standard quantum noise limit. This makes haloscope searches for axions with masses above 0.1 meV unfeasible with current technologies. To overcome this limitation, we propose a new photon counting technique designed to operate at 30-60 GHz for detecting axions with masses between 0.124 meV and 0.248 meV, based on a single electron in a Penning trap. The electron cyclotron mode absorbs microwave photons, and, via the continuous Stern-Gerlach effect, this absorption imparts a measurable phase shift onto the axial motion. In this paper, we comprehensively analyze this photon detection method. We introduce a new type of fast, phase-sensitive axial detection technique, using axial-magnetron parametric amplification to overcome detector Johnson noise and cancel associated frequency shifts. This method may find other applications in precision Penning trap frequency measurements. We compare the efficiency of the electron single-photon counter with an ideal device, and find that our proposed photon counter has sufficient performance to search for high mass axions.

   hep-ph3 citations
6. 06*

   $J/\psi$ Production Within Jets at the EIC

   Yunlu Wang🇨🇳 · Hee Sok Chung🇰🇷 · Taewook Ha🇨🇳 · Daekyoung Kang🇨🇳 · U-Rae Kim🇰🇷

   We present theoretical predictions for the transverse-momentum distribution of $J/\psi$ produced within jets at the upcoming Electron-Ion Collider (EIC). Utilizing the semi-inclusive fragmenting jet function (FJF) framework, our calculation achieves next-to-leading order (NLO) accuracy in the strong coupling and leading-logarithmic (LL) accuracy by resumming both collinear and threshold logarithms. In contrast to the gluon-dominated regime of the LHC, EIC photoproduction is characterized by an enhanced quark-initiated component, offering a complementary probe into the charmonium production mechanism governed by nonperturbative long-distance matrix elements (LDMEs). We examine the impact of representative LDME sets, demonstrating the EIC's distinct discriminating power for the mechanisms. We find that quark contributions are particularly significant in the small momentum fraction region. This region is also shown to be sensitive to both the jet radius $R$ and the experimental muon identification criteria for the $J/\psi \to {\mu }^{+}{\mu }^{-}$ decay channel. These findings establish quarkonium-in-jet observables at the EIC as a vital, independent probe for constraining the production mechanisms and advancing our understanding of heavy quarkonium formation.

   hep-phJHEP(2026)·2 citations
7. 07*

   Analytical description of the distributions of primary and secondary cosmogenic particles

   Shvetaank Tripathi🇮🇳 · Prashant Shukla🇮🇳

   In this work, we present an analytical description of the energy distributions of primary and secondary cosmogenic particles on Earth in terms of parameters having clear physical meaning. A modified power law is assumed for energy distributions, incorporating terms such as energy loss/decay, which are effective at low energies, and a source term, which is dominant at high energies. The parametrizations of the momentum distribution of primary protons and helium have been obtained including energy loss term. For muons, both the energy loss and decay terms have been included. It is shown analytically that zenith angle distributions is given by ${\cos }^{n-1}\theta$ in terms of energy index $n$ and the presence of decay term does not affect it. The analytical function describes the muon momentum distribution data at different altitudes and zenith angles. The same form is also applied to describe the atmospheric muon and electron-type neutrino distributions simulated at various sites. The presented analytical functions provide an excellent description of all kinds of cosmogenic particles.

   hep-phAdv.High Energy Phys.(2026)·0 citations
8. 08*

   The Hadronization Impact on $J/\psi$ Energy Correlators: A Pythia8 Study from Partonic to Hadronic Observables

   Jin-peng Zhang🇨🇳 · Qian Yang🇨🇳 · Wen-Chao Zhang🇨🇳 · Yu-jiao Zhao🇨🇳

   A comprehensive study of the $J/\psi$ energy correlator as a probe of non-perturbative hadronization in color-octet $c\bar{c}$ production is performed. The energy correlator measures the energy flow as a function of the angular distance ($\chi$) from the identified $J/\psi$ meson. Using the PYTHIA 8 Monte Carlo event generator, the correlator is computed at both parton and hadron levels. At high $J/\psi$ transverse momentum ($p_T>7\text{GeV}/c$), the parton-level correlator in the $\cos \chi >0$ region is dominated by soft gluon emission during the hadronization of the color-octet state, a contribution clearly distinguishable from other partonic sources, such as underlying multi-parton interactions. The transition to the hadron level, however, introduces substantial modifications, suppressing the correlator in this region by approximately an order of magnitude and underscoring the complexity of the hadronization mapping. Further analysis reveals that the hadron-level observable exhibits notable sensitivity to model parameters: increasing the mass splitting between colored $c\bar{c}$ pre-resonances and the $J/\psi$ meson from 0.2 to 0.8 GeV/$c^2$ enhances the correlator by up to $60\%$, while extending the color reconnection range yields a milder enhancement of about $10\%$. These findings demonstrate that precise measurements of the hadron level $J/\psi$ energy correlator, when interpreted within robust event-generator frameworks, can provide novel constraints on hadronization dynamics and help clarify the production mechanisms of $J/\psi$ state.

   hep-phPRD(2026)·1 citation
9. 09*

   Towards Accurate Gravitational Wave Predictions: Gauge-Invariant Nucleation in the Electroweak Phase Transition

   Jie Liu🇨🇳 · Renhui Qin🇨🇳 · Ligong Bian🇨🇳

   The vacuum decay in the early Universe should be gauge-invariant. In this work, we study the gauge dependence of the vacuum decay occurring through a first-order phase transition and the associated gravitational wave production. We investigate the gauge dependence of the bubble nucleation and phase transition parameters within the framework of the Standard model effective field theory in three dimension. By considering the power-counting and utilizing the Nielsen identity at finite temperature, we show that, depending on the power-counting scheme favored by the new physics scale, the perturbative computation methodology allow we get the gauge-independent nucleation rates and phase transition, this enables more accurate predictions of gravitational wave signatures.

   hep-phastro-ph.COhep-th7 citations
10. 10*

    Near-threshold heavy quarkonium photoproduction in a light-front spectator model

    Amrita Sain🇨🇳 · Bheemsehan Gurjar🇮🇳 · Chandan Mondal🇨🇳

    The near-threshold photo- and electroproduction of heavy vector quarkonia off the proton provides direct access to its gluonic structure. In particular, the cross section for $J/\Psi$ photoproduction near threshold is governed by the proton's gluon gravitational form factors (GFFs). In this work, we employ the generalized parton distribution framework together with gluon GFFs calculated in a light-front gluon-spectator model inspired by soft-wall AdS/QCD to predict both the differential and total cross sections for near-threshold $J/\Psi$ and ${\rm Y}$ photoproductions. Our results for $J/\Psi$ photoproduction show good agreement with recent experimental data from the $J/\Psi$-007 and GlueX Collaborations at Jefferson Lab, as well as with earlier measurements from SLAC and Cornell.

    hep-phhep-exhep-lathep-th+1PRD(2026)·3 citations
11. 11*

    Dispersive description of the $K\to \pi {\ell }^{+}{\ell }^{-}$ radiative amplitudes

    Véronique Bernard🇫🇷 · Sébastien Descotes-Genon🇫🇷 · Marc Knecht🇫🇷 · Bachir Moussallam🇫🇷

    We propose a description of the $K^{+}$, $K_S$ radiative decay form factors $W_{+}$, $W_S$ based on general properties of analyticity and unitarity. Starting from the simple consideration of the asymptotic behaviour of the two combinations $2W_{+}-W_S$ and $W_{+}+W_S$ we derive a dispersive representation involving only two parameters. Using the rich experimental information on the $K\to 3\pi$ amplitudes, extended beyond the low energy region using the Khuri-Treiman formalism, we show that the sign of the $W_{+}$ form factor is unambiguously determined and its energy dependence can be well reproduced. We also show that the yet unknown $\Delta I=1/2$ part of the $K_S\to {\pi }^{+}{\pi }^{-}{\pi }^0$ can be determined from the value of $W_{+}(0)+W_S(0)$. The possibility of fixing the sign of $W_S$ from experiment is discussed.

    hep-ph0 citations
12. 12*

    Naturally small Dirac neutrino mass and $B-L$ dark matter

    Ernest Ma🇺🇸 · Partha Kumar Paul🇮🇳 · Narendra Sahu🇮🇳

    In the conventional gauged $B-L$ extension of the standard model, the $B-L$ charge of the singlet scalar $\chi$, responsible for the breaking of $U(1{)}_{B-L}$ symmetry, is taken to be 2 such that it can anchor type-I seesaw by giving Majorana masses to the right-handed neutrinos, ${\nu }_R$. In this paper, we consider instead the cases $\chi \sim 3$ or 4 under $B-L$, so that ${\nu }_R$ may not acquire any Majorana mass and neutrinos are Dirac fermions. We then consider a vector-like fermion $S$ with 2 units of $B-L$ charge, which becomes a good candidate for dark matter, either Dirac for $\chi \sim 3$ or Majorana for $\chi \sim 4$. In both cases, spontaneous $B-L$ breaking can induce a strong first-order phase transition, producing stochastic gravitational waves (GW) which can be tested at GW experiments. Moreover, the presence of light ${\nu }_R$s gives rise to an additional contribution to the effective number of relativistic degrees of freedom, $\Delta N_{\mathrm{eff}}$, providing complementary constraints from current and upcoming CMB observations.

    hep-phastro-ph.CO6 citations
13. 13*

    Gravitational Ionization by Schwarzschild Primordial Black Holes

    Alexandra P. Klipfel🇺🇸 · David I. Kaiser🇺🇸

    Primordial black holes (PBHs) are theorized to form from the collapse of overdensities in the very early Universe. PBHs in the asteroid-mass range $10^{17}\mathrm{g}\lesssim M\lesssim 10^{23}\mathrm{g}$ could serve as all or most of the dark matter today, but are particularly difficult to detect due to their modest rates of Hawking emission and sub-micron Schwarzschild radii. We consider whether the steep gradients of a PBH's gravitational field could generate tidal forces strong enough to disrupt atoms and nuclei. Such phenomena may yield new observables that could uniquely distinguish a PBH from a macroscopic object of the same mass. We first consider the gravitational ionization of ambient neutral hydrogen and evaluate prospects for detecting photon radiation from the recombination of ionized atoms. During the present epoch, this effect would be swamped by Hawking radiation -- which would itself be difficult to detect for PBHs at the upper end of the asteroid-mass window. We then consider the gravitational ionization and heating of neutral hydrogen immediately following recombination at $z\simeq 1090$, and identify a broad class of PBH distributions with typical mass $5\times 10^{21}\mathrm{g}\lesssim M\lesssim 10^{23}\mathrm{g}$ within which gravitational interactions would have been the dominant form of energy deposition to the medium. We also identify conditions under which tidal forces from a transiting PBH could overcome the strong nuclear force, either by dissociating deuterons, which would be relevant during big bang nucleosynthesis (BBN), or by inducing fission of heavy nuclei. We find that gravitational dissociation of deuterons dominates photodissociation rates due to Hawking radiation for PBHs with masses $10^{14}\mathrm{g}\lesssim M\lesssim 10^{16}\mathrm{g}$. We additionally identify the phenomenon of gravitationally induced fission of heavy nuclei via tidal deformation.

    hep-phastro-ph.COastro-ph.HEnucl-thPRD(2026)·5 citations
14. 14*

    Threshold resummation of Semi-Inclusive Deep-Inelastic Scattering

    Stefano Forte🇮🇹 · Giovanni Ridolfi🇮🇹 · Francesco Ventola🇮🇹

    We derive threshold resummation of semi-inclusive deep-inelastic scattering (SIDIS), by building upon previous results by some of us for the resummation of the Drell-Yan process at fixed rapidity, which is related to SIDIS by crossing. We consider both a double-soft limit, in which both the Bjorken and the fragmentation scaling variables tend to their threshold value, and single soft limits in which either of them does. We show that in the former limit only soft radiation contributes, and in the latter limit only collinear radiation, and we derive resummed expressions for the coefficient functions in all cases. We determine explictly resummation coefficients in the nonsinglet channel up to next-to-next-to-leading log by comparing to recent fixed next-to-next-to-leading order results. Expanding out the single-soft resummation we reproduce recent next-to-leading power results.

    hep-phEPJC(2026)·1 citation
15. 15*

    Hadronic Probes of Non-Standard Neutrino Interactions

    Carlos Henrique de Lima🇨🇦 · David McKeen🇨🇦 · John Ng🇨🇦 · Douglas Tuckler🇨🇦

    In this work, we study leptonic decays of hadrons as probes of light neutrinophilic scalars that mediate enhanced neutrino self-interactions. Such scalars can be emitted in processes involving neutrinos, turning two-body decays into three-body final states and producing characteristic spectral distortions. We compute these effects for charged pion decay and nuclear electron capture decay, including both on-shell and off-shell scalar emission, as well as the loop-induced renormalization required to cancel divergences. Using these results, we derive the projected sensitivity of PIONEER and assess the current and future reach of BeEST. The resulting low-energy spectral tails provide a characteristic signal for light neutrinophilic scalars, making upcoming hadron decay experiments powerful probes of light mediators of non-standard neutrino self-interactions.

    hep-phhep-exnucl-thPRD(2026)·4 citations
16. 16*

    One-loop renormalization and $\mathbf{\rho }$ parameter in the Georgi-Machacek model

    Debtosh Chowdhury🇮🇳 · Anirban Kundu🇮🇳 · Poulami Mondal🇮🇳 · Subrata Samanta🇮🇳 · Aaryan Srivastava🇮🇳

    We study the one-loop renormalization of the Georgi-Machacek model. At one loop, the renormalization of the model is phenomenologically important when triggered by operators that are absent at the tree level due to the global $SU(2{)}_R$ symmetry. By computing all the tree-level parameters from the standard input parameters ${\alpha }_e$, $G_{\mu }$, and $m_Z$, we show the ultraviolet divergent nature of the electroweak $\rho$ parameter when one-loop corrections are incorporated. In this model, four input parameters are required to completely parametrize the electroweak precision observables at one loop. We study the quantitative impact of the model parameters on the one-loop corrections to the $\rho$ parameter. At one loop, the $\rho$ parameter shows a mild dependence on the mass differences between the custodial fiveplet and the heavy custodial singlet, and mainly depends on the ratio of the doublet and triplet vacuum expectation values, and on the mixing angle between the custodial singlet CP-even scalars.

    hep-phhep-ex1 citation
17. 17*

    Primordial black holes: constraints, potential evidence and prospects

    Bernard Carr🇬🇧 · Antonio J. Iovino🇦🇪 · Gabriele Perna🇪🇪 · Ville Vaskonen🇪🇪 · Hardi Veermäe🇪🇪

    Primordial black holes (PBHs) may have formed in the early Universe and may account for all or part of the dark matter. In this review, we summarize the current observational constraints on PBHs across the full mass range, highlight potential evidence for their existence, and outline the prospects for future searches, particularly with gravitational-wave observatories. We also discuss different PBH formation scenarios, identify the corresponding mass functions, and present the observational constraints in each case.

    ↳ astro-ph.COgr-qchep-phRiv.Nuovo Cim.(2026)·73 citations
18. 18*

    Improving TauFinder Reconstruction at a 10 TeV Muon Collider with the MAIA Detector Concept

    Cyrus Kianian (1)🇺🇸 · Moses Glassman (1)🇺🇸 · Abdollah Mohammadi (1) ((1) Department of Physics, University of Wisconsin-Madison, USA)🇺🇸

    This study aims to improve the TauFinder reconstruction algorithm for the MAIA detector concept. Through this work, we seek to increase the reconstruction efficiency and identification of hadronically decaying tau leptons. Through our work, we introduce a dynamic signal cone, known as a shrinking cone, which adjusts its size based on the transverse momentum of the tau candidate. In addition to the already studied one charged hadron and three charged hadron decay modes we extend TauFinder to include decays that consist of one charged hadron and up to two neutral pions. Furthermore, we have developed a tagger that prevents electrons being misidentified as one-prong tau candidates. Applying this tagger results in near-perfect electron rejection with negligible decrease in one-prong tau reconstruction efficiency.

    ↳ physics.ins-dethep-exhep-ph0 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.