Thu·Mar 20, 2025Thursday·March 20, 2025

1. 01*

   Modular $S_3$ flavoured Pati-Salam model with two family seesaw

   A. E. Cárcamo Hernández🇨🇱 · Ivo de Medeiros Varzielas🇵🇹 · S. F. King🇬🇧 · Vishnudath K. N🇨🇱

   We present a unified model of quarks and leptons with modular $S_3$ flavour symmetry, where the two lightest family masses are naturally suppressed via a Pati-Salam version of the type I seesaw mechanism, mediated through heavier vector-like fermions. Majorana neutrino masses are further suppressed through a double seesaw mechanism. The viable parameter space has a preferred range of the modulus field with Im$(\tau )\sim 2$, leading to successful fermion masses and mixing. The prediction for neutrinoless double beta decay is partly within the reach of the nEXO experiment. In particular, the Dirac CP violating neutrino oscillation phase is predicted to lie in the range ${\delta }_{\mathrm{CP}}^{\nu }\sim 260^o-360^o$.

   hep-phPRD(2025)·2 citations
2. 02*

   Advances in Local Analytic Sector Subtraction: massive NLO and elements of NNLO automation

   Gloria Bertolotti🇬🇧 · Giovanni Limatola🇩🇪 · Paolo Torrielli🇮🇹 · Sandro Uccirati🇮🇹

   In this article we present a number of developments within the scheme of Local Analytic Sector Subtraction for infrared divergences in QCD. First, we extend the scheme to deal with next-to-leading-order (NLO) singularities related to massive QCD particles in the final state. Then, we document a new implementation of the NLO subtraction scheme in the MADNKLO automated numerical framework, which is constructed to host higher-order subtraction algorithms. In particular, we discuss improvements in its performances with respect to the original implementation. Finally we describe the MADNKLO implementation of the first elements relevant to Local Analytic Sector Subtraction at next-to-next-to-leading order (NNLO), in the case of massless QCD partons in the final state.

   hep-ph4 citations
3. 03*

   Cosmological gravitational particle production: Starobinsky vs Bogolyubov, uncertainties, and issues

   Duarte Feiteira (1)🇫🇮 · Oleg Lebedev (1) ((1) Department of Physics and Helsinki Institute of Physics, Helsinki, Finland)🇫🇮

   We study production of free and feebly interacting scalars during inflation using the Bogolyubov coefficient and Starobinsky stochastic approaches. While the two methods agree in the limit of infinitely long inflation, the Starobinsky approach is more suitable for studying realistic situations, where the duration of inflation is finite and the scalar field has non-trivial initial conditions. We find that the abundance of produced particles is sensitive to pre-inflationary initial conditions, resulting in the uncertainty of many orders of magnitude. Nevertheless, a lower bound on the particle abundance can be obtained. High scale inflation is very efficient in particle production, which leads to strong constraints on the existence of stable scalars with masses below the inflationary Hubble rate. For example, free stable scalars are allowed only if they have masses below an eV or the reheating temperature is in the GeV range or below. We find universal scaling behavior of the particle abundance, which covers free and feebly interacting scalars as well as those with a small non-minimal coupling to gravity. These considerations are important in the context of non-thermal dark matter since inflationary particle production provides an irreducible background for other production mechanisms.

   hep-phastro-ph.COhep-thJCAP(2025)·10 citations
4. 04*

   Meson Mixing Bounds on $Z^{\prime }$ Mass in the Alignment Limit: Establishing the Phenomenological Viability of the 331 Model

   Patricio Escalona🇧🇷 · João Paulo Pinheiro🇪🇸 · A. Doff🇧🇷 · C. A. de S. Pires🇧🇷

   We perform a systematic study of flavor-changing neutral currents (FCNCs) in the 331 model with right-handed neutrinos (331RHNs), analyzing constraints on the $Z^{\prime }$ boson mass from $K$-, $D$-, $B_d$-, and $B_s$-meson oscillations. By explicitly incorporating scalar sector dynamics and quark rotation ambiguities ($V_L^{u,d}$), we demonstrate that $Z^{\prime }$ mass limits depend critically on the parametrization of Cabibbo-Kobayashi-Maskawa (CKM) matrix factors. Three scenarios are explored: (i) $V_L^u=V_{\text{CKM}}^{†}$ (FCNCs restricted to $D$-mesons), (ii) $V_L^d=V_{\text{CKM}}$ (dominant $B_s$ constraints), and (iii) a hybrid mixing pattern. Strikingly, scenario (i) reduces the $Z^{\prime }$ mass bound to $M_{Z^{\prime }}\gtrsim 600\text{GeV}$-two orders of magnitude below literature values-by leveraging large experimental uncertainties in $D$-$\bar{D}$ oscillations. Conversely, scenario (ii) requires $M_{Z^{\prime }}\gtrsim 165\text{TeV}$ due to stringent $B_s$ data. We further establish the alignment limit $\cos (\varphi +\phi )=0$ for the SM-like Higgs, showing its viability depends on $V_L^{u,d}$ configurations, with $B_s$ systems enforcing $|\cos (\varphi +\phi )|<0.01$ in down-sector FCNC scenarios. Our analysis reveals that strategic choices of quark mixing matrices can suppress FCNC visibility, reconciling the 331 framework with flavor data without ultra-heavy $Z^{\prime }$ bosons. This work provides the first unified treatment of SM-like Higgs- and $Z^{\prime }$-mediated FCNCs in 331 models, identifying viable parameter spaces for collider phenomenology.

   hep-phJHEP(2025)·7 citations
5. 05*

   Strong CWoLa: Binary Classification Without Background Simulation

   Samuel Klein🇨🇭 · Matthew Leigh🇨🇭 · Stephen Mulligan🇨🇭 · Tobias Golling🇨🇭

   Supervised deep learning methods have been successful in the field of high energy physics, and the trend within the field is to move away from high level reconstructed variables to lower level, higher dimensional features. Supervised methods require labelled data, which is typically provided by a simulator. As the number of features increases, simulation accuracy decreases, leading to greater domain shift between training and testing data when using lower-level features. This work demonstrates that the classification without labels paradigm can be used to remove the need for background simulation when training supervised classifiers. This can result in classifiers with higher performance on real data than those trained on simulated data.

   hep-phMach.Learn.Sci.Tech.(2026)·1 citation
6. 06*

   Systematics of doubly heavy tetraquarks: nonstrange and strange

   Kai-Kai Zhang🇩🇪 · Wen-Xuan Zhang🇨🇳 · Duojie Jia🇨🇳

   Masses, magnetic moments and color-spin structures of nonstrange and strange tetraquarks with two heavy quarks are systematically studied in QCD string picture with chromomagnetic interaction. Our mass computations combined with weak and radiative decays indicate that there are two doubly-heavy tetraquarks, the bottom-charmed tetraquark $T_{cb}(7173,01^{+}{)}^0$ and the doubly-bottom tetraquark $T_{bb}(10406,01^{+}{)}^{-}$, to be stable against the strong decay, having the lifetimes of $0.069$ fs and $326$ fs, respectively. Magnetic moments are also computed and found to be sensitive to chromomagnetic mixing of the color-spin configurations of these tetraquarks, being valuable probe to experimentally detect the nontrivial color configuration $6_c\otimes {\bar{6}}_c$.

   hep-phPRD(2025)·6 citations
7. 07*

   Lepton Flavor Violation of Z Gauge Boson Decays in Supersymmetric Type-III Seesaw Model

   Vael Hajahmad🇹🇷 · Murhaf Alsayed Ali🇸🇾

   In this study, we investigate the lepton flavor violation (LFV) of Z gauge boson decaying into two different flavor charged leptons $Z\to l_i{l}_j$ ($Z\to \tau \mu$, $Z\to \tau e$ and $Z\to \mu e$). This work is performed in the framework of the constrained minimal supersymmetric standard model (CMSSM) which is extended by the type-III seesaw mechanism. By considering constraints from the current experimental bounds on neutrino and supersymmetric particle masses, we calculate the branching ratios of the LFV of $Z$ boson decays. The numerical results are found to be $1.30\times {10}^{-9}$ for both the $\tau \mu$ and $\tau e$ decay channels and $6.40\times {10}^{-10}$ for the $\mu e$ channel. After applying the constraints from the experimental bounds on the radiative two body decays $l_i\to l_j\gamma$, the branching ratios of the LFV of $Z$ boson decays get an additional suppression of $10^{-3}$ for the $\tau \mu$ and $\tau e$ decay channels and $10^{-8}$ for the $\mu e$ channel. Our prediction of the branching ratios is several orders of magnitude below the current experimental bounds.

   hep-phBraz.J.Phys.(2025)·0 citations
8. 08*

   Suppression of elliptic anisotropy inside jets: A new perspective for jet quenching

   Meng-Quan Yang🇨🇳 · Wei-Xi Kong🇨🇳 · Peng Ru🇨🇳 · Ben-Wei Zhang🇨🇳

   Particle azimuthal anisotropies inside jets, defined within the momentum plane perpendicular to the jet axis, carry the information of the QCD cascade process for jet formation. In this work, we propose to measure the medium-induced modifications of the elliptic anisotropy inside jets in relativistic heavy-ion collisions to provide novel insight into the jet quenching phenomenon. By simulating the jet propagation in the hot and dense nuclear medium with a Linear Boltzmann Transport model, we observe a de-correlation in the two-particle azimuthal angular distribution for inclusive jet production in AA collisions relative to that in pp collisions, which results in significant suppression of the in-jet elliptic anisotropy coefficient $v_2$. This phenomenon arises from the stochastic and strong interactions with the thermal QGP medium undergone by the jet particles. Furthermore, the nuclear modifications of the in-jet $v_2$ are found to be sensitive to the medium properties in the model study, which provide a potential probe for the jet tomography of nuclear matter.

   hep-phnucl-thPLB(2025)·1 citation
9. 09*

   State-of-the-art cross sections for ttH: NNLO predictions matched with NNLL resummation and EW corrections

   Roger Balsach🇩🇪 · Alessandro Broggio🇦🇹 · Simone Devoto🇧🇪 · Andrea Ferroglia🇺🇸 · Rikkert Frederix🇸🇪 · Massimiliano Grazzini🇨🇭 · Stefan Kallweit🇨🇭 · Anna Kulesza🇩🇪 · Javier Mazzitelli🇨🇭 · Leszek Motyka🇵🇱 · Davide Pagani🇮🇹 · Benjamin D. Pecjak🇬🇧 and 4 other authors

   We present new, state-of-the-art predictions for the associated production of the SM Higgs boson with top quarks, computed in accordance with the recommendations of the LHC Higgs Working Group. The NNLO QCD predictions, derived through suitable approximations of the two-loop virtual contribution, are supplemented with soft-gluon resummation up to NNLL accuracy. Two distinct resummation frameworks are employed - one based on direct QCD and the other on soft-collinear effective theory - and their features are compared in detail. These results are further combined with the complete-NLO corrections, yielding the most precise SM predictions for this process to date. The relevant sources of theoretical uncertainties are thoroughly estimated and discussed.

   hep-phhep-exSciPost Phys.Comm.Rep.(2025)·8 citations
10. 10*

    Two- and Three-gluon Glueballs within the Helicity Formalism

    Cyrille Chevalier🇧🇪 · Vincent Mathieu🇪🇸

    Both positive and negative charge conjugation glueball spectra are computed with a constituent gluon approach. We first compute the spectrum of the Hamiltionian describing two-gluon bound states having $C=+$, before tackling the three-gluon bound states having $C=-$. We review the construction of two and three particle helicity states in order to build totally symmetric wave functions for our glueball states. In the literature, two different couplings schemes are used to build three particles states. We derive for the first time the relation between these two three-body state definitions. The glueball spectra are compared with those obtained from quantum chromodynamics simulations on a lattice. The two-gluon glueball spectra show a good agreement with the constituent approach and the numerical lattice simulations. The three-gluon spectrum is in overall agreement with the masses observed on the lattice but also predicts additional low-lying states.

    hep-phPRD(2025)·6 citations
11. 11*

    Non-Hermitian electron-positron annihilation under thermal effects

    D. S. Cabral🇧🇷 · A. F. Santos🇧🇷 · R. Bufalo🇧🇷 · N. B. Xavier🇧🇷

    In this paper we examine the thermal effects into the $e^{+}{e}^{-}\to {\ell }^{+}{\ell }^{-}$ scattering in a non-hermitian extension of QED. We compute the thermal contributions to this scattering cross-section within the Thermo Field Dynamics approach. In order to highlight the non-hermitian effects we have considered some limits of interest: i) zero-temperature limit and high-energy limit and ii) high-temperature regime. Since this type of scattering possesses accurate experimental data for the cross-section (for muon and tau at the final state) it can be used to set stringent bounds upon the non-hermitian parameters.

    hep-phhep-thEur.Phys.J.Plus(2025)·1 citation
12. 12*

    Photon Absorption in a Doubly Special Relativity Model with Undeformed Free Propagation and Total Momentum Conservation

    J. M. Carmona🇪🇸 · J. L. Cortés🇪🇸 · F. Rescic🇪🇸 · M. A. Reyes🇪🇸 · T. Terzić🇭🇷

    The lack of a dynamical framework within doubly special relativity theories has impeded the development of a corresponding phenomenology of modified interactions. In this work we show that in a model based on the classical basis of $\kappa$-Poincaré and total momentum conservation, one has a well-defined cross section of the photon-photon annihilation process, once a prescription for the channel treatment is set. The modification of the interaction can lead to observable effects in the opacity of the Universe to very high-energy gamma rays when the gamma-ray energy approaches the energy scale of the deformation. The magnitude and observability of this deformation are examined as functions of the gamma-ray energy and source distance.

    hep-phastro-ph.HEgr-qcJCAP(2025)·1 citation
13. 13*

    Open Heavy flavor mesons in hot asymmetric strange hadronic matter -- A QCD sum rule approach

    Amruta Mishra🇮🇳

    The in-medium masses of the pseudoscalar open charm ($D$, $\bar{D}$, $D_s$ and $\overline{D_s}$) and open bottom ($B$, $\bar{B}$, $B_s$ and $\overline{B_s}$) mesons in hot asymmetric strange hadronic matter are studied within a QCD sum rule approach. These are computed using the medium modifications of the light quark condensates ($⟨\overline{q_i}{q}_i⟩$, with $(q_i,i=1,2,3)\equiv (u,d,s)$), the gluon condensates and other operators in the operator product expansion upto mass dimension 5. Within a chiral SU(3) model, the quark condensates are obtained from the medium modifications of the non-strange and strange scalar-isoscalar fields ($\sigma$ and $\zeta$), and the scalar-isovector field, $\delta$, whereas, the gluon (scalar and twist-2) condensates are computed from the in-medium value of the dilaton field, $\chi$, which is incorporated within the chiral model to mimic the broken scale invariance of QCD. The splittings of the masses of the $D-\bar{D}$ ($B-\bar{B})$, as well as $D_s-\overline{D_s}(B_s-\overline{B_s})$ in the hadronic medium are due to the odd part of the spectral function. For the strange-charm (strange-bottom) mesons ($(q_i,i=3)\equiv s$), the value of $⟨{q_i}^{†}{q}_i⟩$ dominates over the contributions from the other operators of the odd part of the spectral function. This is observed as opposite behaviour of the particle-antiparticle mass splittings with the mass of the particle to be larger (smaller) than the antiparticle mass in nuclear (hyperonic) matter. The density and isospin asymmetry effects are observed to be the dominant medium effects which might have observable consequences on the production of charmonia and open charm mesons, and, on the production ratios, $D^{+}/D^{-}$ and $D^0/\overline{D^0}$, in asymmetric heavy ion collisions in the CBM experiment at FAIR at the future facility at GSI.

    hep-phPRD(2025)·1 citation
14. 14*

    Towards a general subtraction formula for NNLO QCD corrections to processes at hadron colliders: final states with quarks and gluons

    Federica Devoto🇺🇸 · Kirill Melnikov🇩🇪 · Raoul Röntsch🇮🇹 · Chiara Signorile-Signorile🇩🇪 · Davide Maria Tagliabue🇩🇪 · Matteo Tresoldi🇩🇪

    We describe the calculation of integrated subtraction terms in the nested soft-collinear subtraction scheme for hadron collider processes with quarks and gluons, thereby extending the results presented in Ref. [1]. Although this extension eventually proves to be straightforward, it requires a more careful treatment of certain collinear limits to achieve a compact and physically-transparent final result. We also show that the cancellation of infrared divergences can be organized in such a way that, once soft contributions are removed, it occurs independently for each of the external partons. We consider these results to be important stepping stones on the way to deriving finite remainders of the integrated subtraction terms for fully-general hadron collider processes in the context of the nested soft-collinear subtraction scheme.

    hep-phJHEP(2025)·17 citations
15. 15*

    Study of hadron interactions and compositeness

    Tetsuo Hyodo🇯🇵

    Plenty of hadrons have been established experimentally, yet the nonperturbative nature of the strong interaction complicates a comprehensive understanding of their internal structure, particularly for exotic hadrons that extend beyond conventional mesons and baryons. One prominent candidate for the internal structure of exotic hadrons is the hadronic molecule, a loosely bound system of hadrons analogous to atomic nuclei. Understanding such systems requires precise knowledge of hadron interactions, which traditional scattering experiments struggle to provide, especially in the low-energy region. Recent advances, including precise baryon-baryon interaction measurements, femtoscopy techniques that probe momentum correlations between particles, and first-principles lattice QCD calculations, have significantly improved our understanding of hadron interactions. Here, we review these recent developments, demonstrate the successful application of femtoscopy to antikaon-nucleon interactions, utilize the concept of compositeness to quantify the hadronic molecular component of the Lambda(1405), and discuss both experimental and theoretical prospects, including future studies at J-PARC.

    hep-phnucl-th3 citations
16. 16*

    A spacetime model for the perturbative swing

    Torbjörn Lundberg🇸🇪 · Leif Lönnblad🇸🇪

    We present the development of a new colour reconnection model in PYTHIA where the full spacetime separation between partons constrains the reconnection probability throughout the final-state radiative shower. Building upon previous ideas of a perturbative dipole-based model, our objective is to introduce realistic spatially-based colour reconnections within the Angantyr model for heavy-ion collisions. Previous models were limited to the use of a rudimentary separation measure in the transverse plane to control reconnections. We investigate the impact of this novel scheme on final states in ${\text{e}}^{+}{\text{e}}^{-}$, pp, and pPb collisions as well as in PbPb collision systems and our main goal in this paper is to achieve a reasonable description of basic multiplicities in systems of varying sizes.

    hep-phEPJC(2025)·2 citations
17. 17*

    No Flavor Anisotropy in the High-Energy Neutrino Sky Upholds Lorentz Invariance

    Bernanda Telalovic🇩🇰 · Mauricio Bustamante🇩🇰

    Discovering Lorentz-invariance violation (LIV) would upend the foundations of modern physics. Because LIV effects grow with energy, high-energy astrophysical neutrinos provide the most sensitive tests of Lorentz invariance in the neutrino sector. We examine an understudied yet phenomenologically rich LIV signature: compass asymmetries, where neutrinos of different flavors propagate preferentially along different directions. Using the directional flavor composition of high-energy astrophysical neutrinos, i.e., the abundances of ${\nu }_e$, ${\nu }_{\mu }$, and ${\nu }_{\tau }$ across the sky, we find no evidence of LIV-induced flavor anisotropy in 7.5 years of IceCube High-Energy Starting Events. Thus, we place upper limits on the values of hundreds of LIV parameters with operator dimensions 2-8, tightening existing limits by orders of magnitude and bounding hundreds of parameters for the first time.

    hep-phastro-ph.HEhep-exhep-thJHEP(2026)·9 citations
18. 18*

    Quantum entropy as a harbinger of factorizability

    Henry Bloss🇺🇸 · Brandon Kriesten🇺🇸 · T.J. Hobbs🇺🇸

    Deeply inelastic scattering (DIS) is a powerful probe for investigating the QCD structure of hadronic matter and testing the standard model (SM). DIS can be described through QCD factorization theorems which separate contributions to the scattering interaction arising from disparate scales - e.g., with nonperturbative matrix elements associated with long distances and a perturbative hard scattering kernel applying to short-distance parton-level interactions. The fundamental underpinnings of factorization may be recast in the quantum-theoretic terms of entanglement, (de)coherence, and system localization in a fashion which sheds complementary light on the dynamics at work in DIS from QCD bound states. In this Letter, we propose and quantitatively test such a quantum-information theoretic approach for dissecting factorization in DIS and its domain of validity; we employ metrics associated with quantum entanglement such as a differential quantum entropy and associated KL divergences in numerical tests. We deploy these methods on an archetypal quark-spectator model of the proton, for which we monitor quantum decoherence in DIS as underlying model parameters are varied. On this basis, we demonstrate quantitatively how factorization-breaking effects may be imprinted on quantum entropies in a kinematic regime where leading-twist factorization increasingly receives large corrections from finite-$Q^2$ effects; our findings suggest potential applications of quantum simulation to QCD systems and their interactions.

    hep-phPLB(2025)·8 citations
19. 19*

    Flavour and Electroweak Precision Constraints on a Simplified Dark Matter Model with a Light Spin-0 Mediator

    Lipika Kolay🇮🇳 · Soumitra Nandi🇮🇳

    This work investigates the allowed parameter spaces of a simplified dark matter (DM) model characterized by a spin-0 mediator with masses in the low to intermediate range ($<$ 10 GeV). We systematically divide the parameter space into various mass regions of the mediator and constrain the model parameters using a diverse set of observables, including flavour-changing charged and neutral current processes such as rare and semi-leptonic decays of pseudoscalar mesons (B and K), electroweak precision observables, alongside data from fixed-target experiments. Additionally, we explore the model's capability to explain recent Belle-II data on invisible B-meson decays. Our study includes a detailed examination of DM properties and the constraints from Big Bang nucleosynthesis. We present bounds on model parameters through individual and simultaneous analyses of the available inputs and highlight their implications for understanding DM phenomenology. Furthermore, we obtain bounds on the couplings of the possible gauge-invariant dimension-5 operators, leading to the possible interactions between the spin-0 mediator and the SM gauge bosons and fermions. This study comprehensively investigates the constraints and theoretical implications associated with low-mass spin-0 mediator DM models.

    hep-phPRD(2026)·6 citations
20. 20*

    Probing Benchmark Models of Hidden-Sector Dark Matter with DAMIC-M

    DAMIC-M Collaboration: K. Aggarwal🇺🇸 · I. Arnquist🇺🇸 · N. Avalos🇦🇷 · X. Bertou🇫🇷 · N. Castelló-Mor🇪🇸 · A.E. Chavarria🇺🇸 · J. Cuevas-Zepeda🇺🇸 · A. Dastgheibi-Fard🇫🇷 · C. De Dominicis🇫🇷 · O. Deligny🇫🇷 · J. Duarte-Campderros🇪🇸 · E. Estrada🇦🇷 and 29 other authors

    We report on a search for sub-GeV dark matter (DM) particles interacting with electrons using the DAMIC-M prototype detector at the Modane Underground Laboratory. The data feature a significantly lower detector single $e^{-}$ rate (factor 50) compared to our previous search, while also accumulating a ten times larger exposure of $\sim$1.3 kg-day. DM interactions in the skipper charge-coupled devices (CCDs) are searched for as patterns of two or three consecutive pixels with a total charge between 2 and 4 $e^{-}$. We find 144 candidates of 2 $e^{-}$ and 1 candidate of 4 $e^{-}$, where 141.5 and 0.071, respectively, are expected from background. With no evidence of a DM signal, we place stringent constraints on DM particles with masses between 1 and 1000 MeV/$c^2$ interacting with electrons through an ultra-light or heavy mediator. For large ranges of DM masses below 1 GeV/c${}^2$, we exclude theoretically-motivated benchmark scenarios where hidden-sector particles are produced as a major component of DM in the Universe through the freeze-in or freeze-out mechanisms.

    ↳ hep-exastro-ph.COastro-ph.IMhep-phPRL(2025)·98 citations
21. 21*

    The Origin of the Very-High-Energy Diffuse $\gamma$-Ray Emission: The Case for Galactic Source Cocoons

    Antonio Ambrosone🇮🇹 · Carmelo Evoli🇮🇹 · Benedikt Schroer🇺🇸 · Pasquale Blasi🇮🇹

    The secondary/primary cosmic-ray ratios and the diffuse backgrounds of gamma rays and neutrinos provide us with complementary information about the transport of Galactic cosmic rays~(CRs). We used the recent measurement of the diffuse gamma ray background in the $\sim \mathrm{TeV}-\mathrm{PeV}$ range by LHAASO and of the very high-energy diffuse neutrino background from the Galactic disc by IceCube to show that CRs may be accumulating an approximately energy independent grammage $X\sim 0.4\mathrm{g}\mathrm{c}{\mathrm{m}}^{-2}$, in regions where gamma rays and neutrinos are produced with a hard spectrum, resembling the source spectrum. We speculate that this grammage reflects the early stages of cosmic ray transport around sources, in what are referred to as cocoons, where particles spend $\sim 0.3\mathrm{Myr}$ before starting their journey in the Galactic environment.

    ↳ astro-ph.HEhep-phAstron.Astrophys.(2025)·14 citations
22. 22*

    Axion Stabilization in Modular Cosmology

    John Joseph Carrasco🇺🇸 · Renata Kallosh🇺🇸 · Andrei Linde🇺🇸 · Diederik Roest🇳🇱

    The $SL(2,\mathbb{Z})$ invariant $\alpha$-attractor models have plateau potentials with respect to the inflaton and axion fields. The potential in the axion direction is almost exactly flat during inflation, hence, the axion field remains nearly massless. In this paper, we develop a generalized class of such models, where the $SL(2,\mathbb{Z})$ symmetry is preserved, but the axion acquires a large mass and becomes strongly stabilized during inflation, which eliminates isocurvature perturbations in this scenario. Inflation in such two-field models occurs as in the single-field $\alpha$-attractors and leads to the same cosmological predictions.

    ↳ hep-thastro-ph.COgr-qchep-phJCAP(2025)·20 citations
23. 23*

    Improved Lattice QCD $B_c\to J/\psi$ Vector, Axial-Vector, and Tensor Form Factors

    Judd Harrison🇬🇧

    We present an update of HPQCD's lattice QCD determination of the $B_c\to J/\psi$ vector and axial-vector form factors, and provide new results for the tensor form factors. We use the Highly Improved Staggered Quark action for all valence quarks, together with the second generation MILC $n_f=2+1+1$ HISQ gluon field configurations. This calculation includes two additional ensembles, one with physically light up and down quarks and $a\approx 0.06\mathrm{fm}$ and one with $a\approx 0.03\mathrm{fm}$ on which we are able to reach the physical bottom quark mass. Our calculation uses nonperturbatively renormalised current operators and covers the full kinematical range of the decay. We use our recent results for the heavy-charm susceptibilities, as a function of $u=m_c/m_h$, in order to employ the full dispersive parameterisation for $B_c\to J/\psi$ in our physical-continuum extrapolation. We give updated SM predictions $R(J/\psi )=0.2597(27)$, $A_{{\lambda }_{\tau }}=0.5093(42)$, $F_L^{J/\psi }=0.4421(55)$, and ${\mathcal{A}}_{\mathrm{FB}}=-0.0567(61)$, reducing uncertainties by $29\%$, $45\%$, $40\%$ and $50\%$ respectively. Since our lattice form factors cover the full kinematic range we can use them to test extrapolations using data in a truncated range, at low-recoil. We investigate different physical continuum parameterisation schemes, with lattice results in the first $1/3$ of the kinematic range near $q_{\max }^2$. We find that unexpectedly large systematic uncertainties near $q^2=0$ can emerge when extrapolating synthetic data in the high-$q^2$ region if higher order kinematical terms are omitted from the physical continuum extrapolation. This suggests a potentially underestimated systematic uncerainty entering extrapolations of synthetic lattice QCD data for the related $B\to D^{\ast }\ell \bar{\nu }$ decay from the high-$q^2$ region into the low-$q^2$ region.

    ↳ hep-lathep-phPRD(2025)·5 citations
24. 24*

    Fine-tunings in nucleosynthesis and the emergence of life: Status and perspectives

    Ulf-G. Meißner🇩🇪 · Bernard Ch. Metsch🇩🇪 · Helen Meyer🇩🇪

    We discuss the fine-tunings of nuclear reactions in the Big Bang and in stars and draw some conclusions on the emergence of the light elements and the life-relevant elements carbon and oxygen. We also stress how to improve these calculations in the future. This requires a concerted effort of different communities, especially in nuclear reaction theory, lattice QCD for few-nucleon systems, stellar evolution calculations, particle physics and philosophy.

    ↳ nucl-thastro-ph.SRhep-lathep-ph+1EPJA(2025)·1 citation
25. 25*

    Primordial correlators from multi-point propagators

    Andrea Costantini🇬🇧 · Laura Iacconi🇬🇧 · David J. Mulryne🇬🇧

    A key step in the comparison between inflationary predictions and cosmological observations is the computation of primordial correlators. Numerical methods have been developed that overcome some of the difficulties arising in analytical calculations when the models considered are complex. The PyTransport package, which implements the transport formalism, allows computation of the tree-level 2- and 3-point correlation functions for multi-field models with arbitrary potentials and a curved field space. In this work we investigate an alternative numerical implementation of the transport approach, based on the use of transfer ''matrices'' called multi-point propagators (MPP). We test the novel MPP method, and extensively compare it with the traditional implementation of the transport approach provided in PyTransport. We highlight advantages of the former, discussing its performance in terms of accuracy, precision and running time, as well as dependence on the number of e-folds of sub-horizon evolution and tolerance settings. For topical ultra-slow-roll models of inflation we show that MPPs (i) precisely track the decay of correlators even when PyTransport produces erroneous results, (ii) extend the computation of squeezed bispectra for squeezing values at least one decade beyond those attainable with PyTransport.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2025)·3 citations
26. 26*

    Effects of Dark Matter Self Interactions on Sagittarius and Its Stream

    Connor Hainje🇺🇸 · Oren Slone🇮🇱 · Mariangela Lisanti🇺🇸 · Denis Erkal🇬🇧

    This work explores how assumptions regarding the particle-physics nature of dark matter can alter the evolution of the Sagittarius (Sgr) dwarf spheroidal galaxy and its expansive stellar stream. We run a large suite of $N$-body simulations to model the infall of a Sgr-like dwarf, exploring how the presence of dark matter self interactions impacts its evolution. For a scattering cross section of $\sigma /m_{\chi }=30{\text{ cm}}^2\text{/g}$ (at orbital velocity scales), these interactions result in significantly less stellar mass and little to no dark matter bound to the progenitor at the present day. To isolate the cause of this mass loss, we introduce a novel technique for controlling which pairs of dark matter simulation particles can interact. This enables us to identify ram-pressure evaporation - the scattering of satellite and host dark matter particles - as the primary source of the enhanced mass loss. The rapid disintegration of the Sgr progenitor when self interactions are allowed alters some key properties of the resulting stellar stream, most dramatically suppressing the presence of a "spur" on the apocenter of the trailing stream arm that correlates with the mass of the satellite at last pericenter. We demonstrate how the effects on the Sgr system scale with the particular choice of self-interaction cross section, which affects the degree of ram-pressure evaporation. These findings generalize beyond the Sgr system, underscoring that dwarf stellar streams and dwarf galaxies with close passages may serve as sensitive probes for dark matter self interactions.

    ↳ astro-ph.GAastro-ph.COhep-phApJ(2025)·4 citations
27. 27*

    Stronger Constraints on Primordial Black Holes as Dark Matter Derived from the Thermal Evolution of the Intergalactic Medium over the Last Twelve Billion Years

    Nabendu Kumar Khan (TIFR)🇮🇳 · Anupam Ray (UC Berkeley)🇺🇸 · Girish Kulkarni (TIFR)🇮🇳 · Basudeb Dasgupta (TIFR)🇮🇳

    Primordial black holes (PBHs) have been explored as potential dark matter candidates, with various astrophysical observations placing upper limits on the fraction $f_{\mathrm{PBH}}$ of dark matter in the form of PBHs. However, a largely underutilized probe of PBH abundance is the temperature of the intergalactic medium (IGM), inferred from the thermal broadening of absorption lines in the Lyman-$\alpha$ forest of quasar spectra. PBHs inject energy into the IGM via Hawking radiation, altering its thermal evolution. In this work, we constrain this energy injection by self-consistently modeling its interplay with the cosmological ultraviolet background from galaxies and supermassive black holes. Leveraging IGM temperature measurements spanning the past twelve billion years ($z\sim 0$ to $6$), we derive one of the most stringent constraints on PBH-induced heating from light PBHs within the mass range $10^{15}$-$10^{17}$ g. Specifically, for $M_{\mathrm{PBH}}=10^{16}$ g, we find $f_{\mathrm{PBH}}<5\times 10^{-5}$ at 95\% confidence, with the bound scaling approximately as $M_{\mathrm{PBH}}^4$ at other masses. Our inclusion of helium reionization and low-redshift temperature measurements strengthens previous IGM-based PBH constraints by an order of magnitude or more. Compared to other existing limits, our result is among the strongest, second only to the constraints from the 511 keV line from the Galactic Center, but with distinct systematics. More broadly, this study highlights the IGM thermal history as a powerful and independent probe of beyond-standard model physics.

    ↳ astro-ph.COastro-ph.HEhep-phPRD(2025)·19 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.