Wed·Nov 19, 2025Wednesday·November 19, 2025

1. 01*

   Light-Front Transverse Nucleon Charge and Magnetisation Densities

   Z.-N. Xu🇪🇸 · Z.-Q. Yao🇪🇸 · P. Cheng🇨🇳 · C. D. Roberts🇨🇳 · J. Rodriguez-Quintero🇪🇸 · J. Segovia🇪🇸

   Nucleon elastic electromagnetic form factors obtained using both the three-body and quark + fully-interacting-diquark pictures of nucleon structure are employed to calculate an array of light-front transverse densities for the proton and neutron and their dressed valence-quark constituents, viz. flavour separations of the proton and neutron results. These two complementary descriptions of nucleon structure deliver mutually compatible predictions, which match expectations based on modern parametrisations of available data, where such are available. Amongst other things, it is found that transverse-plane valence $u$- and $d$-quark Dirac radii are practically indistinguishable; but regarding kindred Pauli radii, the $d$ quark value is roughly 10% greater than that of the $u$-quark. Moreover, magnetically, the valence $d$ quark is far more active than the valence $u$ quark, probably because it has much greater orbital angular momentum. Both pictures of nucleon structure agree in predicting that, in a polarised nucleon, the transverse-plane charge densities are no longer rotationally invariant. Instead, for a $+\hat{x}$ polarised nucleon, positive charge is displaced in the $+\hat{y}$ direction, with the opposite effect for negative charge.

   hep-phhep-exhep-latnucl-ex+1PRD(2026)·2 citations
2. 02*

   Production Mechanisms of isoscalar pseudotensor mesons in pion and kaon induced reactions

   Dong-En Lu🇨🇳 · Li-Ming Wang🇨🇳

   The recent observation of the X(2600) resonance by the BESIII Collaboration has motivated a renewed interest in the spectroscopy of light mesons, particularly pseudotensor states. However, a significant theoretical gap exists in the poorly explored spectrum of isoscalar pseudotensor mesons, where several predicted radial excitations remain unobserved. To address this, we investigate the production of four such states (${\eta }_2(4D)$, ${\eta }_2^{\prime }(2D)$, ${\eta }_2^{\prime }(3D)$, and ${\eta }_2^{\prime }(4D)$) employing an effective Lagrangian approach combined with Regge trajectory phenomenology to describe the high-energy behavior of the reactions. Our calculations reveal a distinct production selectivity: the ${\eta }_2(4D)$ state is more prominent in pion induced (${\pi }^{-}p\to {\eta }_{2}n$) reactions, whereas the ${\eta }_2^{\prime }(2D,3D,4D)$ states are preferentially produced in kaon induced ($K^{-}p\to {\eta }_2\Lambda$) processes. Moreover, the total cross sections for these states exhibit characteristic peaks at specific beam momenta, providing clear kinematic windows for their discovery. This study provides the first comprehensive theoretical predictions for the production cross sections of these predicted mesons, offering crucial guidance for future experimental searches.

   hep-phPRD(2026)·0 citations
3. 03*

   Hybrid to Quarkonia transitions

   Rubén Oncala🇪🇸 · Joan Soto🇪🇸

   Hybrid quarkonia -exotic hadrons with explicit gluonic degrees of freedom- have gained increasing attention in hadron spectroscopy, particularly with the ongoing discovery of new XYZ mesons. In this work, we update the spectrum of heavy hybrid mesons in the charmonium and bottomonium sectors using the Born-Oppenheimer Effective Field Theory framework, by incorporating the latest lattice QCD results for hybrid static potentials. We refine earlier calculations and analyze allowed transitions from hybrids to conventional quarkonia, including both spin-conserved and spin-flip decays. We carry out a comprehensive error analysis and discuss the reliability of our results. We compare them to experimental data of the Particle Data Group, which allows us to identify hybrid candidates among the observed XYZ states. We provide hybrid or quarkonium interpretations for nearly all heavy isospin-zero mesons observed and incorporate new hybrid candidates.

   hep-phPRD(2026)·2 citations
4. 04*

   Exploring pion emission properties of (strange) hidden-charm molecular pentaquarks in a chiral quark model

   Li-Cheng Sheng🇨🇳 · Yu-Jie Tang🇨🇳 · Yu-Xin Wan🇨🇳 · Rui Chen🇨🇳 · Dian-Yong Chen🇨🇳

   The internal structure of the exotic $P_c$ and $P_{cs}$ pentaquarks remains an open question. To address this, we demonstrate that pion emission serves as a sensitive probe by calculating its properties within a molecular scenario using the chiral quark model and coupled-channel effects. Our results reveal a strong dependence of the decay widths on the internal structure and spatial wave functions. We therefore expect this study to stimulate experimental measurements of these decays, which are crucial for determining the nature of these states and guiding the search for further molecular partners.

   hep-phEPJC(2026)·0 citations
5. 05*

   Magnetic field induced anomalous pion couplings

   Fabio L. Braghin🇧🇷 · Marcelo Loewe🇨🇱 · Cristian Villavicencio🇨🇱

   Effective pion-constituent quark couplings induced by relatively weak magnetic fields are calculated in the framework based in Weinberg's large Nc Effective Field Theory. These couplings (form factors) vanish in the vacuum. In particular, single-pion couplings to a scalar and a vector constituent quark currents are investigated. These couplings might correspond to a fluctuation of the neutral pion into a scalar quark-antiquark state (meson) and to a vector meson, respectively. Some possible phenomenological implications are discussed.

   hep-ph0 citations
6. 06*

   Inclusive $J/\psi$ productions in pp collisions at $\sqrt{s}=$ 5.02, 7, and 13 TeV with the PACIAE model

   Jin-Peng Zhang🇨🇳 · Guan-Yu Wang🇨🇳 · Wen-Chao Zhang🇨🇳 · Bo Feng🇨🇳 · An-Ke Lei🇨🇳 · Zhi-Lei She🇨🇳 · Hua Zheng🇨🇳 · Dai-Mei Zhou🇨🇳 · Yu-Liang Yan🇨🇳 · Ben-Hao Sa🇨🇳

   We investigate the inclusive $J/\psi$ production in proton-proton (pp) collisions at center-of-mass energies $\sqrt{s}=5.02$, 7, and 13 TeV using the PACIAE 4.0 model. This model extends PYTHIA 8.3 by incorporating partonic and hadronic rescatterings before and after hadronization, respectively. Compared to our earlier study [K.-F. Ye et al., Phys. Rev. C 109, 035201 (2024)], which considered only the color-singlet processes, the present work includes both the color-singlet and color-octet contributions within the non-relativistic QCD (NRQCD) framework. In addition to NRQCD, we also consider the contributions from the cluster collapse and weak decays of $b$-hadrons. We find that the simulated inclusive $J/\psi$ transverse momentum differential cross sections agree well with the experimental data at both the middle and forward rapidities. We provide a quantitative analysis of the relative contributions for different production mechanisms and their energy and rapidity dependence in the inclusive $J/\psi$ production. Furthermore, we offer a quantification of the relative contributions of the various components and their energy and rapidity dependence in the NRQCD channels, including the direct production via the hard scattering and the feed-down from the decays of heavier charmonium states such as $\psi (2S)$, ${\chi }_{c0}$, ${\chi }_{c1}$, and ${\chi }_{c2}$. Finally, we examine the effects of partonic and hadronic rescatterings and offer the quantitative estimate of their impact on the $J/\psi$ production. These results are entirely new and represent a significant step forward in understanding the mechanisms of the inclusive $J/\psi$ production in high-energy pp collisions.

   hep-phnucl-thPRC(2026)·1 citation
7. 07*

   Mass spectra and Mott transitions of neutral mesons at finite temperature and magnetic field in frame of three-flavor Polyakov-extended Nambu-Jona-Lasino model

   Luyang Li🇨🇳 · Min Zhou🇨🇳 · Zhiyang Liu🇨🇳 · Chonglong Xie🇨🇳 · Guoyun Shao🇨🇳 · Shijun Mao🇨🇳

   Mass spectra and Mott transitions of neutral mesons $K_0,{\bar{K}}_0,{\pi }_0,\eta ,{\eta }^{\prime }$ at finite temperature and magnetic field are investigated in a three-flavor PNJL model. We focus on the effect of gluons, which is simulated by the Polyakov potential, and the inverse magnetic catalysis (IMC) effect, which is mimicked by using a magnetic field dependent parameter. Mass spectra show similar structure when introducing the gluon and IMC effect. The mass of $K_0({\bar{K}}_0)$ meson $m_{K_0}=m_{{\bar{K}}_0}$ is controlled by chiral symmetry breaking and restoration. It increases with temperature in the low temperature region, and shows a mass jump at the Mott transition. Further increasing temperature, $m_{K_0}$ firstly decreases and then increases with temperature. ${\pi }_0$ meson is not only the pseudo-Goldstone boson of chiral symmetry breaking, but also influenced by the flavor mixing of ${\pi }_0-\eta -{\eta }^{\prime }$. The behavior of $m_{{\pi }_0}$ is different from $m_{K_0}$ only at high temperature region, which decreases with temperature. $\eta ,{\eta }^{\prime }$ mesons are affected by both the $U_A(1)$ anomaly and the flavor mixing of ${\pi }_0-\eta -{\eta }^{\prime }$. The mass of $\eta$ meson $m_{\eta }$ decreases with temperature in low temperature region and then shows a jump at its Mott transition. After that $m_{\eta }$ firstly decreases and later increases with temperature. ${\eta }^{\prime }$ meson is a resonant state, and its mass $m_{{\eta }^{\prime }}$ continuously decreases and then increases with temperature. The mass jumps of $K_0,{\bar{K}}_0,{\pi }_0,\eta$ mesons are caused by the dimension reduction of the constituent quarks under external magnetic field. In PNJL model, the Mott transition temperature of $K_0,{\bar{K}}_0,{\pi }_0$ mesons ($\eta$ meson) decreases (increases) with magnetic field. The IMC effect leads to no qualitative change to the meson Mott transition temperature but shifts them to the lower values.

   hep-phnucl-th5 citations
8. 08*

   Systematic analysis of $D_{(s)}$ meson semi-leptonic decays in the covariant light-front quark model

   Hao Yang🇨🇳 · Shao-Qin Guo🇨🇳 · Zhi-Qing Zhang🇨🇳

   The weak decays of the $D_{(s)}$ meson provide a pivotal platform to advance our understanding of the Standard Model (SM) and to explore New Physics (NP). In recent years, experiments have collected a significant amount of data on the $D_{(s)}$ meson decays, particularly from BESIII, which provides substantial support for theoretical research. In this work, we systematically investigate the semi-leptonic decays of $D_{(s)}$ meson to pseudoscalar (P), scalar (S), vector (V), and axial-vector (A) mesons within the framework of the covariant light-front quark model (CLFQM). We calculate the form factors of the transitions $D_{(s)}\to P,S,V,A$ and the branching ratios of the corresponding semi-leptonic decays, then compare them with experimental data and results from other theoretical models. The form factor values of the transitions $D_{(s)}\to P,V$ obtained from the CLFQM are consistent with those of other theoretical models and available data in most cases. However, significant discrepancies are found in some specific $D_{(s)}\to S,A$ transitions, such as $D\to a_0(980),a_0(1450)$ and $D_{(s)}\to K_{1B}$, compared to other theoretical calculations. The predicted branching ratios for the semi-leptonic decays $D\to P(V)\ell {\nu }_{\ell }$ with $\ell =e,\mu$ agree well with experimental data and other theoretical results in most decay channels, validating the reliability of the model. However, for some $D\to S(V)\ell {\nu }_{\ell }$ decays, tension exists among different theoretical predictions and experimental results. Further clarification of such differences is necessary. Our study provides important insights into the internal structures for some scalar and axial-vector mesons and serves as a theoretical reference for future experiments.

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

   Chiral Evolution and Femtoscopic Signatures of the $K_1(1270)$ Resonance

   Jia-Ming Xie🇨🇳 · Zhi-Wei Liu🇨🇳 · Jun-Xu Lu🇨🇳 · Haozhao Liang🇯🇵 · Raquel Molina🇪🇸 · Li-Sheng Geng🇨🇳

   We present a comprehensive study of the axial-vector resonance $K_1(1270)$ within the unitarized chiral perturbation theory, focusing on its two-pole structure and manifestation in femtoscopic observables. By considering the dominant $\rho K$ and $K^{\ast }\pi$ coupled channels, we reproduce the well-established double-pole structure and trace the chiral evolution of both poles as functions of the pion mass, using the vector-meson mass trajectories fitted to lattice-QCD data and experimental values. The lower pole, dominantly coupled to $K^{\ast }\pi$, evolves from an above-threshold resonance to a virtual or bound state with increasing pion mass. In comparison, the higher pole, dominantly coupled to $\rho K$, moves downward in energy, reflecting the strengthening of the chiral attraction. The influence of the finite vector-meson widths is systematically examined, showing that their inclusion smooths the pole trajectories without altering their qualitative behavior. Furthermore, femtoscopic CFs are calculated for all relevant vector-pseudoscalar channels in both charged sectors. The results exhibit distinct resonance and bound-state features consistent with the two-pole dynamics. The weak impact of higher channels, such as $\omega \bar{K}$, ${\bar{K}}^{\ast }\eta$, and $\varphi \bar{K}$, confirms that the simplified two-channel treatment captures the essential dynamics of the $K_1(1270)$ resonance. This study demonstrates that combining chiral extrapolation and femtoscopic correlation analyses provides a powerful and complementary framework for connecting lattice-QCD calculations, chiral effective theory, and experimental measurements, offering new insights into the molecular nature and chiral origin of the $K_1(1270)$ resonance.

   hep-phPRD(2026)·7 citations
10. 10*

    Probing Saturon-like Limits in QCD Systems

    Wei Kou🇨🇳 · Xurong Chen🇨🇳

    High-occupancy QCD matter enters a saturated regime when its entropy or occupancy approaches the unitarity bound $\sim 1/\alpha$, the ``saturon" criterion. We test this criterion for protons and nuclei at small $x$ using analytic and numerical solutions of the BK equation. From these solutions we construct the gluon occupancy $N_g(x)$ and a thermodynamic entropy $S(x)$ via an Unruh-like temperature $T=Q_s/(2\pi )$ and an emergent gluon mass $M_g\sim Q_s$. For protons, both $N_g$ and $S$ rise toward small $x$ yet stay below $1/{\alpha }_s$ in our baseline setup. For nuclei, by contrast, the nuclear entropy $S_A$ attains the $1/{\alpha }_s$ benchmark in a small-$x$ window where the proton does not. This singles out nuclei as the natural environment to search for saturon-like behavior and motivates precision small-$x$ measurements and high-occupancy $pA$ and $AA$ collisions.

    hep-phhep-thnucl-thPRD(2026)·1 citation
11. 11*

    Correction to $CP$-asymmetry in ${\rm Y}(4S)$ decays due to the admixture of $B^0{\bar{B}}^0$ in a $C$-even state

    N.A. Panchenko🇷🇺 · S.I. Godunov🇷🇺

    $BB$ pairs from ${\rm Y}(4S)\to BB$ decays are in $C$-odd state. However, there is a small admixture of the $C$-even state and it modifies the time dependent $CP$-asymmetry. The $C$-even component appears due to soft photon emission, breaking the pure $C$-odd nature of the initial state. Using the two-particle wave function formalism, we derive analytical expressions for $CP$-asymmetry in both pure and mixed $C$-parity states. We emphasize the strong energy dependence of the admixture magnitude.

    hep-phhep-exJETP Lett.(2026)·0 citations
12. 12*

    Parton distributions with higher twist and jet power corrections

    Richard D. Ball🇬🇧 · Amedeo Chiefa🇬🇧 · Roy Stegeman🇬🇧

    We present a global determination of parton distribution functions (PDFs) that accounts for higher twist corrections in deep-inelastic scattering (DIS) and linear power corrections for single inclusive jet and dijet production data from the LHC. We determine these corrections and their associated correlated uncertainties using a methodology based on the theory covariance formalism, previously used to account for nuclear uncertainties and missing higher order uncertainties (MHOUs) in global PDF determinations. We then study the impact of the power corrections on the extracted PDFs, and demonstrate an improved description of the data due to a reduced sensitivity to DIS data in the low-$x$ region where higher twist uncertainties are relatively large, and a reduced sensitivity to single inclusive jet data at relatively low $p_T$, where linear power corrections can be significant. Finally, we assess the impact of power corrections on observables relevant to LHC phenomenology, including Higgs production via gluon fusion, and the determination of ${\alpha }_s$. We find that these effects, while small, can be significant, improving perturbative convergence.

    hep-phhep-exEPJC(2026)·9 citations
13. 13*

    Charged Higgs bosons associated with neutral gauge bosons at future multi--TeV muon colliders

    Khiem Hong Phan (Duy Tan Univ.)🇻🇳 · Quang Hoang-Minh Pham (HCMUS)🇻🇳

    The first results for charged Higgs pair production associated with neutral gauge bosons at future multi--TeV muon colliders are presented within the framework of the Two-Higgs-Doublet Model. In the phenomenological studies for the production processes, we first update the parameter space of the Type-X Two-Higgs-Doublet Model. From the viable regions of the parameter space, we compute the production cross sections, including all two-body decay modes of the charged Higgs boson. We mention that all two-body decay modes of the charged Higgs boson are evaluated with one-loop electroweak corrections, with two-loop QCD corrections also included for the decays of the charged Higgs into two fermions. The signal significances are also examined for several benchmark points within the updated parameter space. It is worth emphasizing that the production cross sections used for computing the significances in this work include initial-state radiation corrections up to two-loop order. With the help of the high integrated luminosity planned for future multi--TeV muon colliders, the production signals can be observed with a statistical significance exceeding $5\sigma$ for several selected points within the allowed parameter space.

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

    Impact of conversion-driven processes on singlet-doublet Majorana dark matter relic

    Partha Kumar Paul🇮🇳 · Sujit Kumar Sahoo🇮🇳 · Narendra Sahu🇮🇳

    The singlet-doublet dark matter model offers a rich framework for exploring the nature of dark matter (DM) through its unique fermion structure. In this model, the important parameters are the singlet-doublet mass splitting $\Delta M$, the singlet-doublet mixing angle $\sin \theta$, and the DM mass $M_{\mathrm{DM}}$. If the DM is assumed to be of Dirac nature, then the annihilation, co-annihilation, and conversion driven processes combined allow a range of parameter space: $100\mathrm{GeV}\lesssim M_{\mathrm{DM}}\lesssim 750$ GeV and $10^{-6}\lesssim \sin \theta \lesssim 0.04$ for $\Delta M>1$ GeV. While the nature of DM, either Dirac or Majorana, is not known, in this work, we assume the singlet-doublet DM to be of Majorana type and find that the relic density and direct detection can be satisfied over a larger parameter space. In particular, the allowed ranges of DM mass and $\sin \theta$ are $100\mathrm{GeV}\lesssim M_{\mathrm{DM}}\lesssim 1750$ GeV and $2\times 10^{-7}\lesssim \sin \theta \lesssim 0.45$ for $\Delta M>1$ GeV.

    hep-phastro-ph.COhep-exPRD(2026)·7 citations
15. 15*

    Anomalous spontaneous induction of magnetic and electric fields in dense quark matter

    E. J. Ferrer🇺🇸 · J. M. Perez-Fernandez

    In this paper, we will demonstrate that a dense quark-matter system in the dual chiral density wave (DCDW) phase behaves as a ferromagnet in the sense that its magnetic-field dependent magnetization remains different from zero even at $B\to 0$. The corresponding permanent magnetization is a function of the baryonic chemical potential $\mu$, decreasing up to zero as $\mu$ increases in the range of intermediate densities ($312$ MeV $⩽\mu ⩽342$ MeV) and then increasing from zero in the higher density interval $490$ MeV$⩽\mu ⩽550$ MeV. We will show that this system's ability to generate permanent magnetization, together with the existence of the axial anomaly, open up the possibility of spontaneously generating a magnetic field coupled to a collinear electric field. The generated magnetic field can reach values up to $10^{16}$ G, depending on $\mu$, and the electric field will be 3 orders smaller. The fact that the DCDW phase is able to induce a magnetic field can be seen as its spontaneous tendency to remove the so called Landau-Peierls instability that is present in this single-modulated phase in the absence of a magnetic field. The spontaneous induction of a strong magnetic field at intermediate to high densities can be of interest for the astrophysics of compact stellar objects exhibiting strong magnetic fields as magnetars.

    hep-phnucl-thPRD(2026)·1 citation
16. 16*

    Charmonium production in the TMD factorization using the Improved Color Evaporation Model

    Vladimir Saleev🇷🇺 · Kirill Shilyaev🇷🇺

    In the article, the study of unpolarized $J/\psi$ production in proton-proton collisions is presented. The Soft Gluon Resummation approach as a TMD framework was used for description of small-$p_T^{}$ production cross section. The Improved Color Evaporation model was considered as an approach to describe hadronization of produced quarks into charmonium state. We find that the experimental data at various center-of-mass energies $\sqrt{s}$ demonstrate the dependence of hadronization parameter $F^{J/\psi }$ on energy. The predictions for $J/\psi$ production in the kinematics of the SPD NICA experiment have been made.

    hep-phMoscow Univ.Phys.Bull.(2025)·0 citations
17. 17*

    Probing the Phenomenology of Dark Matter from Decoupled Freeze-Out

    Geneviève Bélanger🇫🇷 · Aoife Bharucha🇫🇷 · Sreemanti Chakraborti🇬🇧 · Rashidul Islam🇮🇳 · Sophie Mutzel🇫🇷

    We consider a model of dark matter where the mediator corresponds to a superposition of a scalar and pseudoscalar, and the scenario where, after reheating, the number densities of the dark sector particles, i.e. the dark matter and the mediators, are negligible. If the coupling of the mediators to the Standard Model is feeble, but the coupling to the dark matter is large enough, the dark sector may reach equilibrium at a temperature distinct from that of the thermal bath. The relic density is then said to be obtained via decoupled freeze out (DFO). We focus on the $s$-wave annihilation scenario, which particularly benefits from the DFO mechanism by evading standard CMB limits while still yielding indirect detection signals. We calculate the relic density by solving a set of four coupled Boltzmann equations for the number densities of the dark sector particles and the energy transfer from the light to dark sector. We finally perform a thorough analysis of experimental bounds on this scenario, namely from indirect detection and the CMB, as well as from BBN, and find that, while there are considerable constraints on the parameter space where the correct relic density is obtained, a viable region remains to be explored.

    hep-phJHEP(2026)·0 citations
18. 18*

    Uncharted Logarithmic Structures in QCD Transverse-Energy Flow

    Mrinal Dasgupta🇬🇧 · Alexander Fraley🇬🇧 · Pier Francesco Monni🇨🇭 · Saad Nabeebaccus🇬🇧

    We investigate the QCD transverse-energy ($E_T$) flow distribution within an azimuthal region of phase space, defined by an angular interval $\Delta \varphi$ on the plane transverse to a chosen jet axis. Vetoes on the resulting $E_T$ are widely employed at the LHC to isolate missing transverse momentum in final states with invisible particles. We show that this observable has logarithmic structures never seen before in QCD calculations. Notably, its description involves the resummation of non-global and coherence-violating logarithmic contributions that are more singular than any reported to date. We analyze its all-orders behavior, providing analytical resummations at next-to-double-logarithmic accuracy for $e^{+}{e}^{-}$ and $pp$ collisions, and numerical resummations at leading-logarithmic accuracy in the Veneziano limit for $pp$ collisions. We further present a computation of the leading coherence-violating correction for $pp$ collisions. The intricate structure of vetoes in azimuthal gaps reveals new aspects of QCD dynamics and offers a novel probe of collinear-factorization breaking at the LHC.

    hep-phhep-th10 citations
19. 19*

    Perturbative aspects of the electroweak phase transition with a complex singlet and implications for gravitational wave predictions

    Thomas Biekötter🇪🇸 · Andrii Dashko🇩🇪 · Maximilian Löschner🇩🇪 · Georg Weiglein🇩🇪

    We present a detailed analysis of strong first-order electroweak phase transitions within the extension of the Standard Model by a complex scalar singlet (cxSM). Focusing on the impact of renormalization scale and gauge dependence, we systematically compare commonly used perturbative frameworks for predicting thermodynamic observables that characterize the phase transition and the associated gravitational-wave (GW) spectrum. These include both the four-dimensional ($4D$) formalism and the dimensionally reduced three-dimensional effective field theory ($3D$ EFT) approach in different renormalization schemes. Within the $3D$ EFT, we compute the effective potential up to two-loop order in a general $R_{\xi }$ gauge, and demonstrate that applying the $\hslash$-expansion yields gauge-independent results in excellent agreement with those obtained from a direct minimization of the loop-corrected potential. In contrast, large discrepancies between the two methods persist in the $4D$ approaches. We find that, across most of the parameter space, the $3D$ EFT approach provides the most robust predictions for phase-transition parameters and GW spectra, reducing theoretical uncertainties in the GW peak amplitude by more than an order of magnitude compared to the $4D$ calculations. We point out, however, that the $3D$ EFT approach is subject to an additional theory uncertainty from truncating the EFT at finite operator dimension and show that higher-dimensional operators within the $3D$ EFT approach can substantially modify the predicted transition strength and GW signals. This indicates a potential breakdown of the high-temperature expansion precisely in the region with the lowest transition temperatures, where the strongest GW signals are expected and the detection prospects with LISA are most promising.

    hep-ph20 citations
20. 20*

    How to pick the best anomaly detector?

    Marie Hein🇩🇪 · Gregor Kasieczka🇩🇪 · Michael Krämer🇩🇪 · Louis Moureaux🇩🇪 · Alexander Mück🇩🇪 · David Shih🇺🇸

    Anomaly detection has the potential to discover new physics in unexplored regions of the data. However, choosing the best anomaly detector for a given data set in a model-agnostic way is an important challenge which has hitherto largely been neglected. In this paper, we introduce the data-driven ARGOS metric, which has a sound theoretical foundation and is empirically shown to robustly select the most sensitive anomaly detection model given the data. Focusing on weakly-supervised, classifier-based anomaly detection methods, we show that the ARGOS metric outperforms other model selection metrics previously used in the literature, in particular the binary cross-entropy loss. We explore several realistic applications, including hyperparameter tuning as well as architecture and feature selection, and in all cases we demonstrate that ARGOS is robust to the noisy conditions of anomaly detection.

    hep-phcs.LGhep-exphysics.data-anPRD(2026)·4 citations
21. 21*

    Lepton flavor violation in photon-induced electron-muon pairs at the HL-LHC

    M. A. Arroyo-Ureña🇲🇽 · O. Félix-Beltrán🇲🇽 · J. Hernández-Sánchez🇲🇽 · C. G. Honorato🇲🇽 · S. Rosado-Navarro🇻🇪

    We show the outstanding potential of the High-Luminosity LHC (HL-LHC) to discover charged lepton flavor violation (cLFV) via the ultra-peripheral process $\gamma \gamma \to e^{\pm }{\mu }^{\mp }$. Using a gauge-invariant Effective Field Theory (EFT) framework -consistent with the most stringent bounds from radiative decays- we perform a full Monte Carlo analysis with multivariate techniques. Our results show that a $5\sigma$ discovery is achievable with an integrated luminosity of ${\mathcal{L}}_{\mathrm{int}}\gtrsim 2700$ fb${}^{-1}$ for favorable benchmark scenarios. This study establishes photon-fusion at the HL-LHC as a powerful probe of cLFV, strongly motivating dedicated searches by the experimental collaborations.

    hep-phPRD(2025)·1 citation
22. 22*

    Low-frequency radio telescopes sensitivity to light dark matter

    Ruben Zatini🇫🇷 · Francesca Calore🇫🇷 · Pasquale Dario Serpico🇫🇷

    Ground-based radio telescopes are routinely used to search for light dark matter (DM) candidates such as axion-like particles or dark photons. These instruments face however inherent limitations to push the searches to masses below $10^{-7}$ eV, due to the effect of the Earth's ionosphere. The extant and planned space- or Moon-based radio telescopes motivate this study: We systematically investigate their sensitivity to resonant conversion of light DM into radio signals from three solar system targets: the Sun, the Earth, and Jupiter. The perspectives are especially encouraging for dark photon searches using the Sun as a target, and for axion-like particles conversion in Jupiter's magnetosphere.

    hep-phastro-ph.HEPRD(2026)·1 citation
23. 23*

    Subleading Color Corrections at Three Loops to the $\mathrm{tr}({\varphi }^2)$ Three-Point Form Factor in $\mathcal{N}=4$ Super Yang-Mills Theory

    Xin Guan🇺🇸 · Bernhard Mistlberger🇺🇸 · Michael Ruf🇺🇸

    We compute three-loop corrections to the three-point form factor of the operator $\mathrm{tr}({\varphi }^2)$ in $\mathcal{N}=4$ Super Yang-Mills theory. In particular, our result is valid beyond the leading-color limit and will consequently be an important input towards extending the amplitude-bootstrap program beyond the leading-color approximation. We find that our analytic formulae are strikingly compact expressions in terms of integer linear combinations of generalized polylogarithms of weight six.

    ↳ hep-thhep-phPRL(2026)·3 citations
24. 24*

    Gravitational Atom Spectroscopy

    Matteo Della Rocca🇮🇹 · Thomas F.M. Spieksma🇩🇰 · Francisco Duque🇩🇪 · Leonardo Gualtieri🇮🇹 · Vitor Cardoso🇩🇰

    Black holes in our Universe are rarely truly isolated, being instead embedded in astrophysical environments such as plasma or dark matter. A particularly intriguing possibility is that light scalar fields form bound states around black holes, producing extended ''clouds'' known as gravitational atoms. When these clouds become sufficiently compact, the spacetime can no longer be described by a vacuum solution of General Relativity. In this regime, one can construct quasi-stationary, spherically symmetric, self-gravitating scalar gravitational-atom configurations. Here, we explore an observationally relevant aspect of these systems by computing their fundamental quasi-normal mode. We present a fully relativistic calculation of the axial modes in both the time and frequency domains, finding frequency shifts relative to the vacuum case that depends mostly on the compactness of the gravitational atom. For sufficiently compact configurations, these shifts may be detectable by current or future gravitational wave detectors.

    ↳ gr-qchep-phhep-thPRD(2026)·4 citations
25. 25*

    The Scoured Spike: Suppression of Indirect Dark Matter Signals by a Hidden Companion

    Jaden Lopez🇺🇸 · Stefano Profumo🇺🇸

    A massive ``dark companion'' -- such as an intermediate-mass black hole or other compact dark object -- orbiting the supermassive black hole at the Galactic Center can dynamically reshape the surrounding dark-matter spike. Through gravitational heating and angular-momentum exchange, the companion excavates a ``scoured'' region that lowers the inner density and suppresses the expected annihilation signal. We quantify this effect by computing the suppression of the dark-matter annihilation $J$-factor induced by such a companion, combining an analytic scouring-radius model with full numerical integrations of the modified density profile. We scan the parameter space of companion mass, orbital separation, system age, and spike slope, explicitly including the interplay with the annihilation plateau. \textcolor{black}{For canonical Gondolo--Silk spikes with ${\gamma }_{\mathrm{sp}}\gtrsim 2$, the scouring radius grows only weakly with injected energy because the binding energy is concentrated at small radii; however, once scouring occurs, the $J$-factor suppression can be substantial, for sufficiently massive or long-lived companions. In the shallower-spike regime with ${\gamma }_{\mathrm{sp}}\lesssim 2$, the same companion drives $r_{\mathrm{scour}}$ to much larger multiples of $R_{\mathrm{core}}$, and even a modest $\sim 10^4{M}_{\odot }$ companion on a $\mathcal{O}(100)\mathrm{AU}$ orbit and $\mathcal{O}(\mathrm{Gyr})$ age can suppress the annihilation flux by one to two orders of magnitude. Whether a steep spike is significantly suppressed therefore depends on the companion's mass and lifetime, not merely on the sign of $(2-{\gamma }_{\mathrm{sp}})$.} The numerical results are accurately captured (typically at the $\lesssim 10\%$ level) by a simple fitting formula in terms of a dimensionless scouring parameter that measures the ratio between the scoured region and the annihilation core. [...]

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2026)·1 citation
26. 26*

    Large Scale White Noise and Cosmology

    Gabriela Barenboim🇪🇸 · Aurora Ireland🇺🇸 · Albert Stebbins🇺🇸

    The generation of white noise on large scales is a generic property of the dynamics of physical systems described by local non-linear partial differential equations. Non-linearities prevent the small scale dynamics from being erased by smoothing. Unresolved small scale dynamics act as an uncorrelated (white or Poissonian) noise (seemingly stochastic but actually deterministic) contribution to large scale dynamics. This white noise exists even when the dynamics is very nearly linear. In cases where the power spectrum is sub-Poissonian on large scales, this noise will dominate on the largest scale power no matter the amplitude of the inhomogeneities. Such is the case in the standard model of cosmology, where the primordial density power spectrum is expected to have an almost Harrison-Zel'dovich, $P[k]\sim k$, spectrum on a much broader range of scales than can be observed. Even though linear gravitational evolution dominates non-linear corrections by a factor $\sim 10^5$, the non-observation of white noise on the Hubble scale precludes the extrapolation of this power law below the comoving $1$pc scale. More generally, observation or non-observation of large scale white noise provides a powerful probe of the universe on very small scales in the early early universe. Gravitational radiation, phase transitions, vorticity, and running of the spectral index are all phenomena that can be probed with large scale white noise. Large scale white noise is a non-optional feature of all cosmological models but one which has not heretofore been appreciated.

    ↳ astro-ph.COhep-phPRD(2026)·7 citations
27. 27*

    Thermodynamic Origin of the Tully-Fisher Relation in Dark Matter Dominated Galaxies: A Theoretical-Empirical Derivation

    V.K. Oikonomou🇬🇷

    In this work we introduce the concept of self-interacting dark matter with scale-dependent equation of state, in the context of which dark matter is collisional and its equation of state is radius-dependent and has the form $P(r)=K(r){\left(\frac{\rho (r)}{{\rho }_{\star }}\right)}^{\gamma (r)}$. We confronted the effectively 2-parameter model with 174 galaxies from the SPARC data, and we found that the rotation curves of 100 galaxies can be perfectly fitted by the model. These galaxies are dark matter dominated, mostly dwarfs, low-luminosity and low-surface-brightness spiral galaxies. We demonstrate that scale-dependent self-interacting dark matter solves the cusp-core issue for dark matter dominated galaxies. More importantly, the structure of the scale-dependent SIDM model produces in a semi-theoretically and semi-empirically way the canonical Tully-Fisher and the baryonic Tully-Fisher relations when these 100 viable dwarfs, low-surface-brightness and low-luminosity galaxies are taken into account. The behavior of the entropy function $K(r)$ is assumed to be $K(r)=K_0\times {\left(1+\frac{r}{r_c}\right)}^{-p}$. The perfect fits of the rotation curves come for a nearly isothermal and virialized dark matter halo, which naturally predicts the correlation $K_0\sim V_{\max }^2$. This correlation holds true empirically as confirmed by the data and we also find empirically $L\sim K_0^2$ from the data, thus the canonical Tully-Fisher relation is reproduced semi-theoretically and semi-empirically. We perform the same task and we find theoretically, for dark matter dominated galaxies, that $K_0\sim V_{\mathrm{flat}}^2$ which is also confirmed empirically from the data, along with the correlation $K_0\sim M_b^{0.5}$, hence the baryonic Tully-Fisher law naturally emerges in a semi-theoretical and semi-empirical manner.

    ↳ astro-ph.COastro-ph.GAgr-qchep-ph+1Phys.Dark Univ.(2026)·3 citations
28. 28*

    Infrared Quantum Electrodynamics and the Rayleigh-Jeans Physics

    Jorge Gamboa🇨🇱 · Natalia Tapia Arellano🇺🇸

    Infrared quantum electrodynamics (IR-QED) acquires a natural geometric interpretation once soft photons are described as adiabatically transported electron-photon clouds. Within this framework, the relevant infrared structure is encoded in a functional Berry phase associated with the space of gauge connections, and the corresponding Berry corrections modify the Rayleigh-Jeans spectrum. The infrared scaling symmetry of the Rayleigh-Jeans law leads to a simple renormalization-group equation whose solution determines the frequency dependence of an effective factor $F_{\mathrm{eff}}(\omega )$ controlling the strength of the electron-photon cloud dressing. As a result, the energy density of the cosmic microwave background (CMB) receives a Berry-induced correction that scales as a power law and produces a frequency-dependent temperature excess in the radio domain. Although the exponent $\gamma$ governing this scaling behaviour is not fixed internally by the present formulation of IR-QED and must instead be determined phenomenologically, the existence and structure of the excess are genuine predictions of the theory. Remarkably, the resulting expression is extremely simple and naturally aligns with the deviations suggested by the ARCADE 2 data. Taken together, these results indicate that Berry phases in IR-QED may lead to observable consequences in the low-frequency tail of the CMB spectrum.

    ↳ hep-thastro-ph.COhep-ph0 citations
29. 29*

    Exact, non-singular black holes from a phantom DBI Field as primordial dark matter

    Tausif Parvez🇮🇳 · S. Shankaranarayanan (IIT Bombay)🇮🇳

    We present the first exact, non-singular black hole solution in General Relativity sourced by a Dirac-Born-Infeld (DBI) scalar field. Crucially, the solution is exclusively supported by \emph{the phantom branch of the DBI action}, dynamically replacing the central singularity with a regular core. The solution is asymptotically flat, possesses non-trivial scalar hair, and replaces the central singularity with a regular 2-sphere. The mechanism for singularity resolution is a dynamical \emph{kinetic stiffness} which also explains the evasion of classical no-hair theorems. We show these black holes evaporate to a non-singular relic with mass of the order of a gram. This provides a robust mechanism to evade standard evaporation constraints, opening a vast, previously forbidden mass window for light \emph{Primordial Black Holes} to constitute dark matter. The model is testable via distinctive gravitational-wave signatures from its scalar hair.

    ↳ gr-qchep-phhep-thPRD(2026)·8 citations
30. 30*

    Cluster phenomena using few-body and Lattice QCD theories

    E. Hiyama🇯🇵 · T. Doi🇯🇵

    With the advancement of first-principles calculations for baryon-baryon interactions, it becomes possible to obtain reliable hyperon-nucleon potentials by lattice QCD simulations with the HAL QCD method. High-precision few-body methods, such as the Gaussian Expansion Method (GEM), are applicable to solve quantum few-body systems up to four- and five-body systems. By combining the HAL QCD potentials with the GEM, one can predict the level structure of novel hypernuclei prior to experimental observation. In this review, we utilize the lattice QCD $N\Xi$ potential obtained by the HAL QCD method to investigate the few-body systems $NN\Xi$ and $NNN\Xi$. Our analysis indicates that the lightest bound $\Xi$ hypernucleus is the $NNN\Xi$ system. To extract detailed information on the isospin and spin components of the $N\Xi$ interaction, we perform a four-body calculation for the $\alpha \alpha N\Xi$ system with the total isospin $T=0$ and $T=1$. We demonstrate that the level structure of this system is sensitive to the isospin and spin dependencies of the $N\Xi$ interaction. Furthermore, we propose experimental investigations to produce the $NNN\Xi$ and $\alpha \alpha N\Xi$ systems via the $(K^{-},K^{+})$ and $(K^{-},K^0)$ reactions on ${}^4$He and ${}^{10}$B targets, respectively.

    ↳ nucl-thhep-lathep-phnucl-exEPJA(2025)·2 citations
31. 31*

    Numerical simulations of magnetic monopole evolution in an expanding universe

    Mark Hindmarsh🇫🇮 · Asier Lopez-Eiguren🇪🇸 · Riikka Seppä🇫🇮 · David J. Weir🇫🇮

    Magnetic monopoles are an inevitable feature of post-inflation symmetry-breaking phase transitions in grand unified theories. Analytic estimates of their density indicate that they are compatible with standard cosmology only if their mass is less than $10^{11}$ GeV. We initiate a programme of numerical studies of monopole dynamics by simulating a gas of 't Hooft-Polyakov monopoles formed by the Kibble mechanism after a phase transition. In this paper we simulate monopoles in a radiation background, but without interactions with the radiation, in order to resolve differences between analytical models. We find that during the radiation era, the monopoles find each other and annihilate efficiently enough to keep their density fraction constant, which supports the modelling of Zel'dovich and Khlopov and Preskill in the epoch when plasma interactions can be neglected. In the matter era the density fraction decreases logarithmically. Further work is needed to quantify the effect of the thermal bath, which is expected to reduce the annihilation rate at later times.

    ↳ astro-ph.COhep-ph5 citations
32. 32*

    Exotic compact objects in Einstein-scalar-Maxwell theories

    Antonio De Felice🇯🇵 · Shinji Tsujikawa🇯🇵

    In k-essence theories within general relativity, where the matter Lagrangian depends on a real scalar field $\varphi$ and its kinetic term $X$, static and spherically symmetric compact objects with a positive-definite energy density cannot exist without introducing ghosts. We show that this no-go theorem can be evaded when the k-essence Lagrangian is extended to include a dependence on the field strength $F$ of a $U(1)$ gauge field, taking the general form $\mathcal{L}(\varphi ,X,F)$. In Einstein-scalar-Maxwell theories with a scalar-vector coupling $\mu (\varphi )F$, we demonstrate the existence of asymptotically flat, charged compact stars whose energy density and pressure vanish at the center. With an appropriate choice of the coupling function $\mu (\varphi )$, we construct both electric and magnetic compact objects and derive their metric functions and scalar- and vector-field profiles analytically. We compute their masses and radii, showing that the compactness lies in the range $\mathcal{O}(0.01)<\mathcal{C}<\mathcal{O}(0.1)$. A linear perturbation analysis reveals that electric compact objects are free of strong coupling, ghost, and Laplacian instabilities at all radii for $\mu (\varphi )>0$, while magnetic compact objects suffer from strong coupling near the center.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2026)·5 citations
33. 33*

    Vortex stability in pseudo-Hermitian theories

    R. A. Battye🇬🇧 · S. J. Cotterill🇬🇧 · P. Millington🇬🇧

    Pseudo-Hermitian (including $\mathcal{P}\mathcal{T}$-symmetric) field theories support phenomenology that cannot be replicated in standard Hermitian theories. We describe a concrete example in which the vortex solutions that are realised in a prototypical pseudo-Hermitian field theory exhibit a novel metastability, despite the model parameters residing within the naively stable regime of exact antilinear symmetry of the vacuum theory. This instability is identified analytically and confirmed through numerical simulations, and it arises from the small breaking of the underlying antilinear symmetry of the pseudo-Hermitian theory due to the presence of the topological defect. This leads to spacetime-dependent parameters in the equations of motion governing fluctuations around the vortex, inducing non-trivial exceptional-point structures and complex frequencies within their spectrum. Aside from offering intriguing possibilities for cosmology, this result serves to illustrate the ability to produce long-lived metastable configurations in pseudo-Hermitian field theories of relevance beyond cosmology and high energy physics.

    ↳ hep-thhep-ph1 citation
34. 34*

    Simulating quantum electrodynamics in 2+1 dimensions with qubits and qumodes

    Victor Ale🇺🇸 · Tommaso Rainaldi🇺🇸 · Enrique Rico🇨🇭 · Felix Ringer🇺🇸 · George Siopsis🇺🇸

    We develop a hybrid qubit-qumode framework for simulating quantum electrodynamics in 2+1 dimensions. In this approach, fermionic matter fields are represented by qubits, while U(1) gauge fields are encoded in continuous-variable bosonic modes whose canonical quadratures capture the electric and vector-potential components of the theory. To reconcile the non-compact phase space of the qumodes with the compact U(1) gauge symmetry, we introduce and compare two complementary constraint-enforcement strategies: (i) a squeezing-based projection that confines qumode states to the unit circle through an effective modification of the inner product, and (ii) a method that dynamically enforces compactness via a penalty Hamiltonian term. We construct the corresponding hybrid Hamiltonian, derive its decomposition into experimentally accessible qubit-qumode gates, and analyze its spectrum in the analytically tractable single-plaquette limit. The hybrid formulation reproduces the correct gauge-invariant dynamics and provides a scalable route toward simulating Abelian lattice gauge theories coupled to fermionic matter on near-term hybrid quantum architectures. Ground-state preparation and convergence are demonstrated using a continuous-variable extension of the Quantum Imaginary Time Evolution (QITE) algorithm, establishing a general framework for hybrid discrete-continuous quantum simulations of lattice gauge theories.

    ↳ quant-phhep-lathep-phnucl-thJHEP(2026)·10 citations
35. 35*

    Early Universe Constraints on Variations in Fundamental Constants Induced by Ultralight Scalar Dark Matter

    Subhajit Ghosh🇺🇸 · Kimberly K. Boddy🇺🇸 · Tien-Tien Yu🇺🇸

    We study the cosmological impact of ultralight dark matter (ULDM) with a quadratic coupling to Standard Model particles. In addition to the suppression of small-scale power from ULDM itself, the coupling induces a variation of fundamental constants that is modulated by the ULDM oscillatory field value. In this work, we consider the ULDM-induced, time-dependent variation of the fine structure constant and the mass of the electron. These variations modify the predicted abundance of light elements during Big Bang nucleosynthesis (BBN) and the process of recombination, thereby affecting the anisotropies of the cosmic microwave background (CMB). We use CMB anisotropy data and baryon acoustic oscillation measurements to obtain constraints on the variation of couplings over a wide range of ULDM masses. We self-consistently account for the modification of the primordial helium abundance during BBN in computing the CMB power spectra. We find that the allowed ULDM fraction of total dark matter abundance is more constrained for ULDM masses $\lesssim 10^{-26}\mathrm{eV}$ in the presence of the variations. Moreover, our constraints on the variational couplings for ULDM masses $\lesssim 10^{-27}\mathrm{eV}$ are stronger than the ones derived from the primordial helium abundance at BBN. Under our ULDM model, the variation of fundamental constants has no appreciable impact on the Hubble constant inferred from CMB data and thus does not present a viable solution to the Hubble tension.

    ↳ astro-ph.COhep-phPRD(2026)·9 citations
36. 36*

    Systems with Quantum Dimensions

    Mikołaj Myszkowski🇩🇰 · Mattia Damia Paciarini🇩🇰 · Francesco Sannino🇩🇰

    We propose quantum-mechanical systems in which the number of spatial dimensions is promoted to a dynamical quantum variable, making the effective dimension state-dependent. Interestingly, systems of this form can exhibit enhanced symmetries compared to their fixed-dimensional counterparts. As an explicit example, we analyze a two-state system for which the number of spatial dimensions is represented by a quantum operator. By evaluating the corresponding partition function, we uncover a temperature-dependent effective dimension. Our framework opens a new avenue for constructing physical systems, from gravity to condensed matter, where the very notion of dimensionality becomes quantum.

    ↳ quant-phcond-mat.otherhep-phhep-th0 citations
37. 37*

    Closing in on $\alpha$-attractors

    Laura Iacconi🇬🇧 · Sukannya Bhattacharya🇪🇸 · Matteo Fasiello🇪🇸 · David Wands🇬🇧

    Recent observations of cosmic microwave background (CMB) anisotropies combined with large-scale structure may point towards higher values of the scalar spectral index, $n_s$. This puts previously preferred inflationary models, such as $\alpha$-attractors, in tension with the new measurements. Pending a resolution of the tension between BAO parameters as determined by CMB datasets and those determined by DESI, we explore in this work the large-$n_s$ regime of $\alpha$-attractor T-models. We show that some T-models can self-consistently produce an extended reheating stage with a stiff equation of state $(\bar{w}>1/3)$, which allows values for $n_s$ closer to unity. We employ constraints from P-ACT-LB-BK18 data to illustrate what large-$n_s$ observations might imply for T-models with monomial potentials. We show that the $n_s$ measurement yields an upper limit on $\alpha$ that is stronger than the one from the tensor-to-scalar ratio only. We find that $n_s$ is maximised for $\alpha \sim 1$, therefore the seven Poincaré models are well placed to deliver large $n_s$. However, the ability of a stiff reheating stage to increase the compatibility of T-models with large-$n_s$ measurements saturates as $\bar{w}\to 1$. Thanks to this effect, we establish that the largest $n_s$ that monomial T-models can produce is $n_s=0.9682$. T-models are therefore highly predictive in the large-$n_s$ regime and our result provides, under the assumption of perturbative reheating, a benchmark which could be used in the future to rule out monomial T-models.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2026)·13 citations
38. 38*

    Constraining the Nature of Dark Matter from Tidal Radii of Cluster Galaxy Subhalos

    Barry T. Chiang🇺🇸 · Isaque Dutra🇺🇸 · Priyamvada Natarajan🇺🇸

    Gravitational lensing by galaxy clusters provides a powerful probe of the spatial distribution of dark matter and its microphysical properties. Strong and weak lensing constraints on the density profiles of subhalos and their truncation radii offer key diagnostics for distinguishing between collisionless cold dark matter (CDM) and self-interacting dark matter (SIDM). Notably, in the strongly collisional SIDM regime, subhalo core collapse and enhanced mass loss from ram-pressure stripping predict steeper central density slopes and more compact truncation radii--features that are directly testable with current lensing data. We analyze subhalo truncation in eight lensing clusters (Abell 2218, 383, 963, 209, 2390, and MACS J0416.1, J1206.2, J1149.6) that span the redshift range <$z_{\text{spec}}$>$\simeq 0.17$-$0.54$ with virial masses $M_{200}\simeq 0.41$-$2.2\times 10^{15}$ M${}_{\odot }$ to constrain SIDM versus CDM. Our results indicate that the outer spatial extents of subhalos are statistically consistent with CDM, corroborated by redshift- and mass-matched analogs from the Illustris-TNG simulations. We conclude that the tidal radii of cluster galaxy subhalos serve as an important and complementary diagnostic of the nature of dark matter in these violent, dense environments.

    ↳ astro-ph.COastro-ph.GAhep-phApJ(2026)·3 citations
39. 39*

    LinApart2: efficient parallel partial fraction decomposition algorithm for denominators with polynomials of general degree

    Levente Fekésházy🇩🇪 · Oliver Schnetz🇩🇪

    We present LinApart2, a major update to the LinApart algorithm for univariate partial fraction decomposition. Unlike its predecessor, LinApart2 can handle denominators of arbitrary polynomial degree without explicit factorization, while retaining the efficiency and parallelizability of the Laurent series method. Benchmarks show substantial speedups in both runtime and memory usage compared to Mathematica's built-in routine Apart and to the Euclidean algorithm, enabling computations that were previously intractable.

    ↳ cs.SChep-ph2 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.