HEP Phenomenology·hep-ph

Wed·Jul 1, 2026Wednesday·July 1, 2026

49 papers—37 primary·12 cross-listed

01
LinApart3: efficient algorithm for multivariate partial fraction decomposition with linear denominators
L. Fekésházy🇩🇪 · A. Kardos🇭🇺
We present LinApart3, an efficient multivariate partial fraction decomposition algorithm for rational functions with linear denominators. Our decomposition algorithm guarantees that each term contains at most as many distinct denominators from the original set as partial fraction variables, introduces no spurious singularities, is independent of variable ordering, and is insensitive to the presence of spectator variables. While general multivariate approaches based on Gröbner bases or Leinartas' method handle arbitrary polynomial denominators, they suffer from intermediate expression swell. LinApart3 replaces polynomial-ideal computations with linear algebra and residue extraction by exploiting the geometry of the hyperplane arrangement defined by the denominators, circumventing this issue just as LinApart did in the univariate case. Because the individual basis contributions are independent, the algorithm is moreover naturally parallelizable. To showcase the utility of our algorithm we implemented the algorithm both in Wolfram Mathematica and FORM.
hep-phhep-thphysics.comp-ph0 citations
02
Boosted Dark Matter from Sagittarius A $^{⋆}$
Javier F. Acevedo🇨🇦 · Adam Ritz🇨🇦
It was recently demonstrated that black hole binaries can gravitationally accelerate ambient dark matter (DM), producing a continuous flux of particles with velocities far exceeding those of the galactic halo. We extend this analysis to the Milky Way's nuclear star cluster, where stellar-mass black holes are expected to orbit in close proximity to the supermassive black hole Sagittarius A $^{⋆}$ . Using numerical simulations, we compute the flux of gravitationally-boosted DM sourced by this region. Because of the high DM density and large population of black holes orbiting deep within Sagittarius A $^{⋆}$ 's gravitational potential, the resulting DM ejecta attain substantially higher rates and energies compared to galactic black hole binaries, with simulated particles reaching velocities of up to $\sim 25, 000 km/s$ . We find that the nuclear star cluster is therefore the dominant source of gravitationally-boosted DM in the Milky Way. Even under conservative assumptions about the DM profile in the inner galaxy, the ejected DM flux from this region can render large-volume DM detectors competitive with lower-threshold experiments in the sub-GeV mass range, independently of the underlying DM particle model. The gravitational nature of the boost also opens up a sizable detection window into heavy inelastic DM scenarios that are otherwise largely inaccessible to conventional halo DM searches.
hep-phastro-ph.HE1 citation
03
$Λ Λ ˉ$ spin correlations in high-energy collisions from quantum channels: an open quantum system view of hadronization
João Barata🇨🇭 · Iván Cuntín🇨🇭 · Enrique Rico🇨🇭 · Bin Wu🇪🇸
We construct a quantum information-centered approach to describe the experimentally observed behavior of hyperon spin-pair correlations in high-energy collider experiments. The evolution of the spin density matrix of the hyperon pair is treated in the language of quantum channels, accounting both for the spin dynamics in $C^{2} \otimes C^{2}$ and for the pair's angular separation $Δ R$ . We show that the experimental data are consistent with an evolution under a two-qubit depolarizing channel, from which a Lindblad master equation is derived. This provides an open quantum system picture of spin dynamics during the hadronization transition, which is not naturally captured by other quantum channels, and we discuss its microscopic origins. These results show that quantum information science can offer new insights into confinement dynamics beyond the classification of entanglement in the final particle states.
hep-phnucl-thquant-ph3 citations
04
Dynamical evolution of the pressure on the bubble wall
Benoit Laurent🇨🇦 · Miguel Vanvlasselaer🇪🇸
First-order phase transitions in the early Universe are pivotal for gravitational wave production, baryogenesis, and dark matter generation. A central question is whether bubble walls reach a subjouguet or ultra-relativistic velocity - a distinction governed by hydrodynamic obstruction, where plasma heating counteracts the vacuum pressure driving the wall. Traditional analyses assume steady-state fluid profiles, but these may fail during the wall's acceleration phase. We study the dynamical evolution of the pressure on the bubble wall in local thermal equilibrium (LTE), combining analytical approximations with numerical hydrodynamic simulations. Our results reveal that the heating wave's formation time often exceeds the wall's acceleration timescale, invalidating steady-state predictions near the Jouguet velocity. We derive a revised criterion for the maximal driving pressure, which separates deflagration/hybrid regimes from detonations/runaway walls. This criterion, validated by simulations, shows that hydrodynamic obstruction is less restrictive than steady state LTE predictions suggest.
hep-phastro-ph.CO2 citations
05
The effect of nuclear recoil on neutrino oscillations: Toward understanding of short baseline anomalies
Luca Parini🇮🇹 · Eugene V. Stefanovich
We studied the structure of the neutrino wave functions produced in nuclear decays, with particular emphasis on the role of nuclear recoil. Although the fraction of the recoil energy associated with a nonzero neutrino mass is extremely small, it gives rise to a notable time-dependent flavor oscillation. For long-lived sources, such as those used in gallium anomaly and reactor anomaly experiments, this recoil-driven oscillation makes a substantial contribution to the observed deficit of (anti)neutrinos.
hep-ph0 citations
06
Quantum Information of Photon Pairs at Lepton Colliders
Kun Cheng🇺🇸 · Tao Han🇺🇸 · Guanghui Li🇨🇳 · Bin Yan🇨🇳
Photon pairs have provided an ideal laboratory for exploring entanglement and Bell inequality violation in low-energy experiments. Extending such studies to high-energy colliders is of great interest but has yet to be explored. Exploiting the photon conversion process for nearly on-shell photons, we formulate a factorization framework and an effective two-qubit description, which enable access to quantum information encoded in photon pairs. Using the existing Belle data set, we estimate that a $7.4 σ$ violation of the Bell inequality could be achieved. The same framework can also probe quantum discord and nonstabilizerness, which could be measured with precisions of 5.6\% and 1.6\%, respectively. All the reconstructed results from photon conversion in the two-qubit framework are found to be consistent with the kinematic approach of real photons, and the formalism can apply to other spin-1 systems in an appropriate two-qubit limit.
hep-ph7 citations
07
Rich Phenomenology from Simple Ingredients: A Review of Confining Dark Sectors
Pouya Asadi🇺🇸 · Austin Batz🇺🇸 · Graham D. Kribs🇺🇸
We review theories with confining dark sectors and their implications for dark matter, cosmology, phenomenology, and unsolved Standard Model puzzles. Models with new strongly-coupled non-Abelian gauge interactions can lead to a variety of dark matter candidates (dark mesons, baryons, glueballs, etc.), as well as mechanisms to generate its abundance and symmetries that explain its stability. There are also many potential discovery channels, including direct detection, indirect detection, astrophysical observables, and colliders, as well as correlations between different experiments. We compile a broad conceptual overview of the literature on this topic, aimed at both theorists looking for which questions remain unanswered and experimentalists looking for novel search opportunities. While the theoretical landscape is vast, there are both unifying features and calculational techniques that apply to various regimes. We particularly highlight applications to explaining the similarity of visible and dark matter energy densities, i.e. the $ab u n d an ce s imi l a r i t y p u z z l e$ . We advocate further exploration of this class of theories in the effort to uncover physics beyond the Standard Model.
hep-phhep-ex6 citations
08
Toponium effects on quantum steering and Bell nonlocality of top quarks
J. A. Aguilar-Saavedra🇪🇸 · S. Rodríguez-Benítez🇪🇸
We investigate quantum steering and Bell nonlocality in top-quark pair production at the LHC near threshold. The toponium contribution strengthens the spin-singlet component and substantially enhances the entanglement between the two quark spins. With current LHC data, quantum steering appears observable with a statistical significance around $10 σ$ . For Bell nonlocality, the statistical significance can also be high close to threshold, reaching about $9 σ$ , although the feasibility of such a measurement will depend crucially on the control of systematic uncertainties.
hep-phhep-exquant-ph0 citations
09
A Geometric Framework for CPT Violation in Neutral Meson Mixing Using Biorthogonal Bargmann Invariants
Swarup Sangiri🇮🇳
We develop a geometric framework for characterizing CPT violation in neutral meson systems using Bargmann invariants formulated within a biorthogonal description of the non-Hermitian effective Hamiltonian governing neutral meson mixing. Interpreting CPT violation as a relative geometric deformation of the heavy- and light-state mixing directions in projective flavor space, we construct a fourth-order Bargmann invariant together with its CP-conjugate counterpart involving the physical mass eigenstates and experimentally accessible decay channels. From the phase of a rephasing-invariant product of these invariants, we define a geometric observable that isolates the CPT-violating contribution. The resulting formalism identifies the channel dependence of the geometric response and yields a selection criterion for decay-mode combinations exhibiting linear sensitivity to CPT violation. We further relate the geometric deformation to the Lorentz-violating coefficients of the Standard-Model Extension, showing that the resulting observable inherits the characteristic sidereal modulation of the SME framework. The present work provides a complementary geometric perspective on CPT violation in neutral meson mixing and establishes a foundation for future phenomenological studies of geometric signatures of CPT and Lorentz violation.
hep-ph0 citations
10
A Levitated-Magnet Vector Force Sensor for Spin-Dependent Exotic Interactions
Dorian W. P. Amaral🇪🇸 · Lei Cong🇩🇪 · Tim M. Fuchs🇬🇧 · Hendrik Ulbricht🇬🇧 · Dmitry Budker🇩🇪
We present a magnetically levitated ferromagnetic vector force sensor that enables selective searches for spin-dependent exotic interactions mediated by beyond-Standard-Model bosons. A defining feature of spin-dependent exotic interactions is that they can generate forces with distinct directional signatures set by the relative spin configuration of the interacting bodies. We show that our sensor resolves these signatures by mapping forces along different axes onto distinct translational modes with different resonance frequencies, thereby separating interaction channels within the same coupling class. As a representative example, we study parity-violating axial-vector--vector interactions mediated by a spin-1 $Z^{'}$ boson between a sensing and a driving levitated ferromagnet. Using a matched-filter likelihood analysis, we show that a setup based on an already demonstrated experiment can probe the pure electron--electron coupling $g_{A}^{e} g_{V}^{e}$ in the previously inaccessible force range $λ ≲ 1 cm$ , corresponding to mediator masses $M_{Z^{'}} ≳ 1 0^{- 5} eV / c^{2}$ . Our results establish levitated ferromagnets as a promising platform for millimeter-scale searches for spin-dependent fifth forces and for resolving the multiple effective potentials associated with a given coupling class.
hep-phhep-exquant-ph1 citation
11
Regularized Compton double scattering via unitarity
Shanmuka Shivashankara🇺🇸 · Isra Gashi🇭🇷
When two initially entangled photons each undergo Compton scattering, the scattered electrons become correlated. However, the final reduced density matrix of one scattered pair is not influenced by the other scattered pair due to unitarity. Herein, we keep unitarity up to tree level for Compton double scattering and obtain different results than recent literature. The initial four particles, where the initial photons are entangled, are written as a superposition of two states with a relative phase. The final density matrix has two area divergences that are regularized with unitarity. The regularization procedure, i.e. solving for the roots of a polynomial that represents the probability for no scattering, suggests a novel definition of the scattering cross-section. Vieta's formulas relate these divergences to finite cross-sections. For an initial pure state, the formulas for the final density matrix and the correlation of final electronic polarizations are given. The correlation implies double scattering is analogous to Young's diffraction experiment. The two initial superposed states are the circular apertures while the Feynman amplitudes are the interfering complex light fields.
hep-phmath-phmath.MPquant-ph0 citations
12
Extraction of the nucleon axial form factor from Lattice QCD using NNLO chiral perturbation theory
Fernando Alvarado🇩🇪 · Luis Alvarez-Ruso🇪🇸
We calculate the nucleon axial form factor in relativistic chiral perturbation theory with $Δ (1232)$ up to next-to-next-to-leading order (NNLO). Relevant low-energy constants are determined by fitting to recent lattice-QCD results at several pion masses, while accounting for the uncertainty associated with the truncation of the chiral expansion. We obtain a good description of the lattice data for momentum transfers up to $Q^{2} ≃ 0.6$ GeV and pion masses up to $M_{π} ≃ 400$ MeV. We find that the explicit inclusion of the $Δ$ resonance is required to reproduce the lattice-QCD pion-mass dependence of the axial charge and axial radius, as well as the momentum dependence of the form factor. At the physical point we obtain $g_{A} = 1.257 \pm 0.011$ and $⟨ r_{A}^{2} ⟩ = 0.312 \pm 0.037 fm^{2}$ . Our analysis provides a model-independent and systematically improvable parametrization of the pion-mass and momentum dependence of the axial form factor, offering a framework for extrapolating lattice-QCD results to the physical point and for improving predictions of low-energy weak interactions involving nucleons.
hep-phhep-exhep-latnucl-th2 citations
13
LUNAR: a Monte Carlo generator for bound-nucleon decay in liquid argon
Jaroslaw Nowak🇬🇧
The search for nucleon decay in liquid-argon time-projection chambers requires a quantitative description of how the bound nuclear environment reshapes the decay-product kinematics. We present LUNAR, a fast, openly available Monte Carlo generator dedicated to two-body decays of protons and neutrons bound in argon-40, the target nucleus of the DUNE far detector. The parent nucleon is drawn from a selectable nuclear ground state -- ten momentum distributions ranging from mean-field Fermi gases to argon spectral functions -- and bound off the mass shell by one of three removal-energy prescriptions, including the momentum-dependent optical potential of Juszczak \textit{et al}. The two-body decay is performed off-shell and boosted to the laboratory frame, and the daughter meson is then propagated out of the nucleus by a semi-classical intranuclear cascade with an optional formation zone for the freshly produced meson. We use the generator to separate the distinct roles of Fermi motion and binding in shaping the observable meson spectrum, to quantify final-state interactions channel by channel, and to translate present Super-Kamiokande limits into expected DUNE event yields for the full set of standard decay modes. Final-state interactions leave the supersymmetry-favored $p \to K^{+} ν ˉ$ signal essentially intact while roughly halving the pion, $η$ , and antikaon rates -- an effect that dominates over the $\pm 10%$ spread induced by the choice of nuclear model. The code is released to the community as a lightweight, extensible tool for signal efficiency and systematics studies.
hep-phnucl-th2 citations
14
Search for New Physics through the Observables of Semileptonic $B_{c}^{+} \to D^{*+} ℓ^{+} ℓ^{-}$ Decay
Zohaib Aarfi🇵🇰 · Qazi Maaz Us Salam🇵🇰 · Faisal Munir Bhutta🇵🇰 · Ishtiaq Ahmed🇵🇰 · M. Ali Paracha🇵🇰
Motivated by the current flavor anomalies and the comparatively less explored nature of the $b \to d$ sector, we present a model-independent study of the rare semileptonic $B_{c}^{+} \to D^{*+} ℓ^{+} ℓ^{-}$ ( $ℓ = μ, τ$ ) decay, to investigate its sensitivity to New Physics effects. The analysis incorporates penguin-box contributions, long-distance resonance effects, and the sizable weak-annihilation amplitudes. Using the $B_{c} \to D^{*}$ transition form factors calculated in the covariant confined quark model and the weak-annihilation form factors obtained within the Bethe--Salpeter approach, we analyze the differential branching fraction, forward-backward asymmetry, longitudinal helicity fraction, and a comprehensive set of normalized angular observables in several one- and two-dimensional New Physics scenarios and compare our results with the Standard Model predictions. Notably, the branching fraction, forward-backward asymmetry, and the normalized angular coefficients such as, $⟨ I_{2 c} ⟩$ , $⟨ I_{3} ⟩$ , $⟨ I_{5} ⟩$ , and $⟨ I_{6 s} ⟩$ , show clear sensitivity to New Physics effects. Our results indicate that the decay $B_{c}^{+} \to D^{*+} ℓ^{+} ℓ^{-}$ serves as a complementary probe of the flavor structure of New Physics and can therefore be investigated in future measurements at LHCb and other high-luminosity flavor experiments.
hep-ph0 citations
15
Phenomenology of Long-Lived Dark Photons and Axion-Like Particles in a Mixed Portal Framework
Caglar Zorbilmez🇹🇷 · Beyhan Tatar🇹🇷 · Azmi Ali Altintas🇹🇷
We investigate the phenomenology of a dark photon $A'$ and an axion-like particle (ALP) ,$a$, connected through a mixed portal framework which simultaneously allows the conventional visible decay $(A^{'} \to f f ˉ)$ and the exotic cascade process $(A^{'} \to aγ \to 3 γ)$ . We derive the relevant decay widths, branching ratios, and Lorentz-boosted decay lengths, and introduce a dominance parameter $D=\Gamma(A'\to a\gamma)/\Gamma_{\rm SM}$ to distinguish Standard Model-dominated and cascade-dominated regions, with the transition occurring at $(D = 1)$ . A detailed analysis of both light $(0.1 \leq m_{A^{'}} \leq 10 GeV)$ and heavy $(10 \leq m_{A^{'}} \leq 100 GeV)$ dark-photon scenarios shows that the exotic channel can substantially modify the expected dark-photon signatures, transforming otherwise long-lived or detector-stable states into experimentally accessible displaced multi-photon events. In addition, the ALP sector itself may exhibit long-lived particle behavior, leading to distinct displaced diphoton signatures. Our results show that mixed dark-photon-ALP portals offer a rich LLP phenomenology that can be explored at future high-luminosity lepton colliders such as the FCC-ee.
hep-ph0 citations
16
A multi-differential constraint map for quarkonium suppression mechanisms in high-multiplicity pp and pPb collisions
Renato Campanini🇮🇹
The multiplicity-dependent suppression of $Υ (n S)$ excited states in high-multiplicity $pp$ and $p$ Pb collisions is analysed using publicly available CMS and LHCb data; preliminary CMS Physics Analysis Summary results in $p$ Pb and light-ion collisions are used only as supporting cross-system evidence. Six complementary differential constraints are considered: cone isolation, azimuthal-sector equivalence, transverse sphericity, transverse-momentum ordering, forward- $E_{T}$ long-range correlation, and the pPb/Pbp forward-backward asymmetry. Taken together, these constraints disfavour mechanisms controlled solely by local track density or by total multiplicity, and are consistent with an early, globally correlated, topology-sensitive suppression pattern. The characteristic multiplicity scale at which suppression sets in is independently consistent with the onset of a qualitative change in soft-sector behaviour identified by Campanini and Ferri \cite{CampaniniFerri2011} from inclusive charged-particle observables. The result is a data-driven constraint map consistent with an early, coloured pre-hadronic environment, possibly involving a deconfined stage.
hep-ph0 citations
17
Complementary Probes of Light Higgsinos: Electroweak Precision Measurements and Dark Matter Direct Detection
Koichi Hamaguchi🇯🇵 · Natsumi Nagata🇯🇵 · Genta Osaki🇯🇵
Although higgsinos are well motivated to be light from the viewpoint of naturalness, they remain difficult to detect experimentally because they interact only through electroweak interactions and typically possess a compressed mass spectrum. While higgsino dark matter can be efficiently probed by direct detection experiments when gauginos are relatively light, the sensitivity rapidly deteriorates for heavier gauginos due to the suppression of higgsino-gaugino mixing. In this paper, we investigate the prospects for probing light higgsinos through future electroweak precision measurements. Focusing on scenarios in which charginos and neutralinos are the only light electroweakly interacting superparticles, we evaluate their contributions to the electroweak oblique parameters as well as to the precision observables $M_{W}$ and $sin^{2} θ_{eff}$ . We compare the projected sensitivities of future $e^{+} e^{-}$ colliders with those of dark matter direct detection experiments. We find that future electroweak precision measurements provide a powerful probe of higgsinos with masses $≲ 500 GeV$ , including parameter regions with highly compressed spectra and spin-independent scattering cross sections below the neutrino fog. On the other hand, dark matter direct detection experiments are particularly sensitive to scenarios with larger charged-neutral mass splittings induced by higgsino-gaugino mixing, and can probe higgsino dark matter all the way up to the thermal relic mass of $≃ 1 TeV$ . Our results demonstrate the strong complementarity between electroweak precision measurements and dark matter direct detection experiments in exploring light higgsinos and testing supersymmetric scenarios motivated by naturalness.
hep-ph1 citation
18
FRG analysis of dense two-color QCD within the linear sigma model
Gergely Fejős🇭🇺 · Daiki Suenaga🇯🇵
We investigate the phase structure, hadron masses, and topological susceptibility in the two-flavor and two-color QCD (QC $_{2}$ D) medium, particularly focusing on the $U (1)_{A}$ axial anomaly effects. To this end, we employ the linear sigma model, and hadron fluctuations are incorporated through the functional renormalization group method. We establish in detail an effective potential that respects symmetries of QC $_{2}$ D at finite quark chemical potential, $μ_{q}$ : $S U (2)_{L} \times S U (2)_{R}$ chiral, $U (1)$ baryon-number, parity and time-reversal symmetries. We find that the $U (1)_{A}$ anomaly couplings for mesons at finite temperature are enhanced with increasing $μ_{q}$ , while that of the baryons are not too sensitive to $μ_{q}$ . Despite the anomaly enhancement, we find that the topological susceptibility at larger $μ_{q}$ is always suppressed regardless of the temperature, following chiral restoration. We also find that mass degeneracies of the chiral partners are well realized at higher temperatures and densities by the chiral restoration. Our findings are expected to provide useful information on properties of the $U (1)_{A}$ anomaly in medium for sign-problem-free lattice simulations of QC $_{2}$ D.
hep-phhep-latnucl-th2 citations
19
The effect of TMD evolution on the Sivers asymmetry in back-to-back $J / ψ + γ$ and $J / ψ + jet$ production at the Electron-Ion-Collider
Arghya Jana · Asmita Mukherjee🇮🇳 · Sangem Rajesh🇮🇳
We present an estimate of the Sivers asymmetry in back-to-back $J / ψ$ -photon and $J / ψ$ -jet production in electron-proton collisions in the kinematics of the upcoming Electron-Ion Collider (EIC) in a transverse momentum dependent (TMD) factorization framework, and also incorporating the TMD evolution. We use the non-relativistic Quantum Chromodynamics (NRQCD) model to study the production mechanism of $J / ψ$ . The gluon induced channel dominates, and these are promising probes of the less known gluon Sivers function. We incorporate the TMD evolution in the cross section and Sivers asymmetry in the Collins-Soper-Sterman (CSS) approach and show that the asymmetry is sizable even after the evolution. Although the cross section for $J / ψ$ -jet production depends on the long-distance matrix element (LDME) set chosen, the asymmetry remains largely unaffected. The asymmetry is independent of the LDME at leading order for $J / ψ$ -photon production. Thus, the Sivers asymmetry in both processes is a robust probe of the gluon Sivers function.
hep-ph0 citations
20
Evidence for differential kinetic freeze-out of the $ϕ (1020)$ meson in Pb-Pb collisions at $s_{NN} = 2.76$ TeV
Neeraj🇮🇳 · Amal Sarkar🇮🇳
In heavy-ion collisions, hadronic species with small interaction cross sections may decouple from the evolving fireball earlier than the bulk, yet quantitative evidence for this differential freeze-out has remained elusive. We report that the $ϕ (1020)$ meson does \emph{not} kinetically freeze out with the bulk hadrons in 0--5\% central Pb-Pb collisions at $s_{NN} = 2.76$ TeV: a Boltzmann-Gibbs blast-wave contour analysis of ALICE $ϕ (1020)$ $p_{T}$ transverse-momentum spectra shows that the bulk $π / K / p$ freeze-out point is excluded at $4.1 σ$ ( $Δ χ^{2} = 21.7$ ). Despite its proton-like mass, the $ϕ$ exhibits freeze-out parameters incompatible with those of the bulk hadrons, implying that the observed spectral hardening cannot be attributed solely to mass-dependent collective expansion. Instead, it is naturally explained by the OZI-suppressed $ϕ$ -hadron interaction cross section which causes $ϕ$ to decouple earlier and probe a distinct freeze-out surface. The exclusion is robust under all systematic variations tested and is qualitatively reproduced by SMASH hadronic transport simulations. These findings establish the $ϕ$ meson as a clean probe of species-dependent hadronization, and provide quantitative evidence for a kinetic freeze-out hierarchy in ultra-relativistic heavy-ion collisions.
hep-ph0 citations
21
EasyScan_HEP 2: Agent-Ready Parameter Scans for High-Energy Physics
Yang Xiao🇨🇳 · Yuanfang Yue🇨🇳 · Yang Zhang🇨🇳
AI agents are beginning to reshape the preparation and steering of computational workflows in high-energy physics phenomenology. To accommodate this change, we upgrade EasyScan_HEP to make the construction of parameter-scan configuration files more accessible to AI assistance. EasyScan_HEP 2 exposes agent-facing command-line and machine-readable interfaces, allowing an assistant to translate natural language requests into an explicit .ini configuration that defines the scan method, external-program workflow, constraints, and outputs. The resulting configuration can be inspected through a local Web UI. The framework also supports AI-assisted extension to new scan methods, as illustrated by the integration of BESTFIT, EMCEE, and DYNESTY. In this way, EasyScan_HEP 2 adapts parameter scans to AI-assisted workflows while preserving reproducibility, transparency, and user control.
hep-ph1 citation
22
Boosted Higgs-strahlung off a $W$ boson at next-to-next-to-next-to-leading order in QCD
Aude Gehrmann-De Ridder🇨🇭 · Alexander Huss🇨🇭 · Matteo Marcoli🇬🇧 · Pier Francesco Monni🇨🇭 · Emanuele Re🇮🇹 · Luca Rottoli🇮🇹 · Federico Silvetti🇬🇧 · Paolo Torrielli🇮🇹
The production of a boosted Higgs boson in association with a charged weak ( $W$ ) boson is a key process to scrutinize the electroweak symmetry breaking mechanism at hadron colliders. This reaction constitutes the dominant Higgs production channel at large transverse momentum, providing unique sensitivity to Higgs-boson interactions with other Standard Model particles as well as to physics beyond the Standard Model. In this Letter, we present the first fully differential calculation of this important scattering process at next-to-next-to-next-to-leading order (N $^{3}$ LO) in perturbative Quantum Chromodynamics (QCD). We find that the N $^{3}$ LO corrections, amounting to approximately $+ 2%$ in the boosted regime, generally lie at the edge of or outside the standard scale variation band of the previous perturbative order. The residual dependence of the N $^{3}$ LO prediction on perturbative scales is reduced to below the percent level, marking a milestone for the Higgs precision program.
hep-ph0 citations
23
A B-factory continuum retune of PYTHIA 8 hadronization parameters using BELLE and BABAR identified-hadron data
Muhammad Ajaz🇸🇦 · Haifa I. Alrebdi🇸🇦
We refine the hadronization sector of a pp PYTHIA~8 tune in $e^{+} e^{-} \to q q ˉ$ production using selected BELLE and BABAR measurements near the $Υ (4 S)$ region. The study is performed with PYTHIA~8.316 and Rivet~4.1.1 and is restricted to parameters used in this $e^{+} e^{-}$ setup. Starting from the five-parameter hadronization subset of the pp tune, we carry out a staged extension guided by the remaining differences in the BELLE and BABAR data. The final comparison uses a fixed common set of 20,803 bins and samples of 1,000,000 generated events per analysis and tune point. On this basis, the selected refined tune gives a bin-weighted score of 73.42, compared with 76.49 for the Skands $e^{+} e^{-}$ reference and 79.22 for Monash~2013 $e^{+} e^{-}$ . It remains the best-scoring tune for the BELLE charged-hadron, baryon, and single- and dihadron measurements, while Skands still performs better for the BABAR charged-hadron sample and the BELLE meson sample. The bin-weighted ordering is driven primarily by the BELLE 2020 sample. The refined tune gives a small but stable improvement for the selected BELLE and BABAR measurements, although clear differences between the individual datasets remain.
hep-phChinese Physics C (2026)·0 citations
24
Landau-Zener formula and resonant axion conversion in neutron star magnetospheres
Matti Heikinheimo🇫🇮 · Topi Sirkiä🇫🇮 · Kimmo Tuominen🇫🇮
We investigate the Landau-Zener description of resonant axion-photon conversion in neutron star magnetospheres. We find that this picture often fails for axion conversions to millimeter-to-optical band photons due to the characteristic resonance width exceeding the size of the conversion region. This comparison of scales yields a simple criterion for evaluating the validity of the Landau-Zener formula. We verify this criterion numerically, and show that when invalid, the Landau-Zener conversion probability may significantly deviate from the numerical result. In light of these findings, we revise constraints on axions from neutron star optical-band polarization searches.
hep-phastro-ph.HE0 citations
25
Local Minimum of Spin-Sector Magic at the CP-Conserving Point in Low-Energy Neutron-Proton Scattering
Cihang Li🇨🇳 · Teng Ma🇨🇳 · Mingdi Zhu🇨🇳
We study Magic generation in elastic neutron-proton scattering within a leading low-energy spin-sector ansatz that retains the one-pion-exchange spin structures and treats each scattering direction as a conditional two-qubit spin map. We show that the direction-averaged Magic is locally minimized at the CP-conserving (CPC) point $θ ˉ = 0$ at the Clifford point $f_{CPC} = π /4$ , and for the representative non-Clifford CPC backgrounds analyzed here. At $f_{CPC} = π /4$ , the CPC spin map reduces to SWAP up to a phase and therefore generates zero Magic from stabilizer inputs. We further evaluate the complete spin-sector Magic functional by averaging over all 60 two-qubit stabilizer inputs and over scattering directions, and find that the curvature at $θ ˉ = 0$ is positive only within specific windows of the effective CPC phase $f_{CPC}$ . These results identify the CPC point as a local Magic minimum within the restricted low-energy spin sector considered here.
hep-ph4 citations
26
Nonlinear growth and amplification of phase-transition gravitational waves induced by cosmic expansion
Xiao Wang🇦🇺 · Chi Tian🇨🇳 · Csaba Balázs🇦🇺
We perform the first three-dimensional hydrodynamical simulations of cosmological first-order phase transitions in an expanding background. These simulations consistently incorporate the effects of the evolving phase transition strength throughout the full nucleation process of slow phase transitions. We find that, in addition to reducing mean bubble separations via an effectively enhanced nucleation rate, cosmic expansion unexpectedly induces highly nonlinear growth in the gravitational wave energy fraction, ultimately leading to a significant $O (10)$ to $O (100)$ amplification of the gravitational wave spectra. This amplification is more pronounced for initially weak transitions than for those of initially intermediate strength. Our results highlight the challenge and importance of accurately modelling slow phase transitions while accounting for cosmic expansion.
hep-phastro-ph.CO0 citations
27
Optimization of perturbation series in QCD for physical quantities using the renormalization group: necessary conditions and partial results
D. Kotlorz🇷🇺 · S. V. Mikhailov🇷🇺
We explore approaches to numerically optimize a segment of the perturbative series for physical quantities using the QCD renormalization group. We apply these methods to the perturbative series for the coefficient function $C_{B j p s}$ of the Bjorken polarized sum rule and the Adler function $D_{A}$ . Using various techniques proposed in the literature, we discuss the consequences of ``optimization.''
hep-ph1 citation
28
Hadronic exceptional points
Ahmad Jafar Arifi🇯🇵 · Kei Suzuki🇯🇵
Exceptional points, where eigenvalues and eigenvectors coalesce, are a defining feature of non-Hermitian systems and have been extensively observed in photonic, atomic, and condensed matter systems. However, they have received little attention in quantum chromodynamics (QCD), which is the fundamental theory of quarks, gluons, and hadrons. We propose that imaginary magnetic fields provide a simple realization of non-Hermitian dynamics in hadronic systems. Based on two theoretical approaches, a hadronic effective Lagrangian and a constituent quark model, we compute mass spectra of neutral mesons and find exceptional points separating the real-spectrum and complex-eigenvalue regimes. In small fields, the real spectrum exhibits level attraction between hadronic states, whereas in larger fields, hadrons are deconfined, which is a signature of a field-induced inverted potential. Our findings open a new avenue for studying QCD dynamics in non-Hermitian environments.
hep-phhep-lathep-thnucl-th+10 citations
29
Energy-Flow Moments for Elliptic Gluon Wigner Tomography
Lei Wang🇨🇳
The elliptic small- $x$ gluon Wigner distribution correlates transverse momentum with impact parameter, but it is usually accessed through exclusive diffractive dijets whose recoil is sensitive to soft radiation. We propose instead an azimuthal energy-flow moment in DIS dijet production. Within leading-power small- $x$ dijet factorization, its normalized $cos 2 ϕ$ moment is a linear projection of the elliptic Wigner harmonic after a calculable kinematic subtraction, while the final-state energy weighting is infrared and collinear safe. In conjugate recoil space a rotationally scalar Sudakov factor evolves the isotropic and elliptic channels through a fixed $J_{0} / J_{2}$ Hankel pair without $W_{0} \to W_{1}$ leakage. A proof-of-principle calculation gives a per-mille Sudakov-level moment in an unoptimized conservative window, while auxiliary perturbative-window scans reach several per mille. The observable therefore formulates elliptic Wigner tomography as a moment-level energy-flow measurement whose statistical reach can be assessed by simple angular-moment counting.
hep-ph0 citations
30
Collinearly Improved Balitsky-Kovchegov Evolution of the Gluon Wigner Distribution
Lei Wang🇨🇳
We study how collinearly improved small- $x$ evolution modifies the elliptic gluon Wigner distribution and its coherent diffractive dijet $cos 2 ϕ$ signal. Starting from the $S O (3)$ -symmetric Gubser initial condition, we compare fixed-coupling leading-order (LO) BK evolution with the Iancu--Madrigal--Mueller--Soyez--Triantafyllopoulos (IMST) collinearly improved BK prescription, project the evolved dipole to Wigner/GTMD harmonics, and fold the result with photon wave-function hard factors. Within the $S O (3)$ -projected framework, the resummed evolution moves the elliptic node and changes the rapidity and hard-scale dependence of $C_{2}^{coh} = ⟨ cos 2 ϕ ⟩$ , rather than acting as a simple normalization shift. The effect is largest in node-sensitive windows but remains visible in broader sign-stable bins. Direct daughter-coordinate RHS tests and direct $(r, b, ϕ)$ evolution quantify the residual projection ambiguity and check the observed trend. Projection-level EIC-like finite-bin estimates show that balanced high- $Δ$ candidate bins offer a better compromise between elliptic signal and denominator weight than the narrow bins with the largest ratio. The unresummed NLO curve is used only as a stability diagnostic; the physical comparison is between LO BK and IMST collinearly improved BK evolution.
hep-ph0 citations
31
Finite-Density Dynamics of Chemically Equilibrating QGP in Conformal Gubser Flow and Hard Thermal Photon Production
Lakshmi J. Naik🇮🇳 · V. Sreekanth🇮🇳
We study the chemical equilibration of a hot and dense quark-gluon plasma (QGP) at finite baryon density produced in relativistic heavy-ion collisions within conformal Gubser flow. Chemical non-equilibrium is incorporated through fugacity parameters in the parton phase-space distribution functions, whose evolution is governed by master rate equations coupled to the hydrodynamic expansion with transverse flow. We analyse the interplay between chemical equilibration and finite-density dynamics, and investigate its impact on hard thermal photon production. We observe that both finite density and transverse expansion delay chemical equilibration, leading to a chemically undersaturated medium with quarks lagging behind gluons. While the overall thermal photon yield from the expanding system is suppressed in the non-equilibrium scenario, we find an enhanced early-time contribution to high $p_{T}$ photon production. By analyzing the instantaneous photon emission in presence of chemical non-equilibrium, we demonstrate that the rates exhibit a distinct temporal structure arising from the interplay of rapid cooling and evolving fugacities. These features may provide potential observable signatures of chemical equilibration dynamics in the QGP.
hep-phnucl-thJ.Phys.G(2026)·0 citations
32
Emergent Local Phase-Space Scaling in Small-x Gluon Evolution
Lei Wang🇨🇳
Geometric scaling is a central output of nonlinear small- $x$ evolution, but it is less clear whether the same dynamics fixes a probability distribution in transverse phase space. Using fixed-coupling impact-parameter BK evolution in the $S O (3)$ -symmetric construction, we build a normalized gluon Husimi phase-space distribution and resolve it with a local coarse graining whose ultraviolet boundary follows $Q_{s} (Y, b)$ . The main result is a distribution-level one: after this $Q_{s}$ -adaptive resolution, the conditional momentum distributions collapse as functions of $k / Q_{s} (Y, b)$ . The conditional entropy then grows with unit slope relative to $⟨ ln Q_{s}^{2} ⟩$ , as the integrated consequence of that collapse and the two-dimensional momentum measure. Fixed laboratory cutoffs do not show this law, while dense-rapidity, cutoff-window, box-size, regulator-shape, and Husimi-resolution scans keep the $Q_{s}$ -adaptive result stable in the controlled window. Within this fixed-coupling $S O (3)$ -BK setting, the result identifies a local phase-space scaling structure of the gluon Husimi distribution rather than a universal law for unregulated global entropy.
hep-ph0 citations
33
Particle Cosmology
Venus Keus🇮🇪
Particle cosmology is the branch of science that seeks to understand the birth and evolution of the Universe by applying the principles of particle physics. It brings together the physics of the very small (fundamental particles and forces) with the physics of the very large (the structure and evolution of the cosmos). In many ways, the early Universe acts as a natural laboratory - one far more energetic than any collider we can build - offering unique insights into phenomena that may never be accessible on Earth. Cosmological observations such as the Cosmic Microwave Background, the distribution of galaxies, and the accelerating expansion of the Universe serve as windows into the fundamental laws of nature. At the same time, theoretical developments in particle physics have led to theories, such as inflation, baryogenesis, and Dark Matter, that help explain key features of the cosmos.
hep-phgr-qchep-th0 citations
34
NNLO QCD predictions for $t t ˉ W$ production at the LHC
Xiang Chen🇨🇭
The production of a top-antitop quark pair in association with a $W$ boson ( $t t ˉ W$ ) is one of the heaviest signatures currently explored at the Large Hadron Collider (LHC) and the corresponding rates have been found to be consistently higher than the Standard Model predictions, highlighting the need for more accurate theoretical predictions. In this contribution, I present next-to-next-to-leading order (NNLO) predictions for this process, in which, for the first time, the necessary two-loop amplitudes are explicitly evaluated in the generalised leading-colour limit.
hep-ph0 citations
35
PBHs and GWs from Scaling Monopoles
Daiki Aburatani🇯🇵 · Wakutaka Nakano🇯🇵 · Wen Yin🇯🇵
Monopoles with sufficiently weak gauge couplings, or from global symmetries, can form scaling networks in the early Universe whose average energy density tracks the cosmological background. In this work, we find, by performing classical lattice simulations to estimate the overdensities, that primordial black holes (PBHs) with a broad mass spectrum can be produced during this evolution if the Higgs expectation value $v$ satisfies $v ≳ 0.1 M_{pl}$ . The formation is driven by the stochastic realization of the monopole number in Hubble patches causing the overdensities. We also show that gravitational waves (GWs) generated by the scaling dynamics are produced at the same epoch, with spectra correlated with the PBH spectra and with amplitudes testable in future observations. Interestingly, if the scaling regime is terminated by the gauge boson mass for the gauged monopole, a non-negligible fraction of the PBHs can carry magnetic charge, and the resulting magnetic Coulomb force between such charged PBHs is predicted to be comparable to the gravitational force. Together with the PBH and GW signals, this provides a smoking-gun signature of the scenario. We also point out simple cosmological scenarios, which may also apply to PBH formation from scaling cosmic strings, that allow PBHs to constitute dominant dark matter.
hep-phastro-ph.COgr-qc2 citations
36
Reheating in No-Scale Models of Inflation
Ignatios Antoniadis🇺🇸 · John Ellis🇬🇧 · Dimitri V. Nanopoulos🇬🇷 · Keith A. Olive🇺🇸 · Sarunas Verner🇺🇸
Analogously to the suppression of inflaton decays into conformally-coupled scalar fields in the original Starobinsky $R + R^{2}$ model of inflation, inflaton decays to Standard Model fields are also suppressed in minimal no-scale models of inflation with field space curvature $R = 2/3$ . We study how this suppression can be avoided in generalized no-scale inflationary models. These include models in which the field space curvature $R = 2/ (3 α)$ with $α \neq = 1$ as exemplified by models derived from string theory, as well as models with non-minimal gauge kinetic terms and anomaly-induced couplings. We analyze direct and anomaly-induced inflaton couplings to gauge bosons and gauginos and demonstrate the Kähler-frame invariance of the physical gauge coupling. We determine the resulting reheating temperatures and the corresponding predictions in the $(n_{s}, r)$ plane. Finally, we consider an $R^{3}$ deformation of Starobinsky supergravity, which modifies the inflaton and stabilizer sectors but does not, by itself, generate new tree-level inflaton couplings to visible matter fields.
hep-phastro-ph.COhep-th1 citation
37
Quantum Information as a New Lens for Precision Neutrino Physics
Khushboo Dixit🇿🇦 · Ritam Kundu🇮🇳 · Papia Panda🇮🇳 · Soebur Razzaque🇿🇦 · Ramita Sarkar🇮🇳
We present a quantum-information-theoretic study of three-flavor neutrino oscillations in long-baseline experiments by mapping flavor states to qubit-like representations and quantifying quantum correlations through total concurrence. The local minima of this entanglement measure identify energy regions where the flavor state is closest to separability, enabling cleaner extraction of oscillation parameters. We explain how these local minima offer opportunities for precision measurements and provide insight into the accurate determination of neutrino oscillation parameters. We then propose a strategy to improve parameter extraction by aligning the benchmark oscillation regions of NO $ν$ A and T2K with the minimum entanglement achievable in each experiment. This shifts the concurrence minima toward higher-event-count energy regions, leading to tighter constraints and reducing the tension arising from their different energy regimes. For normal ordering, we obtain $(0.58 1_{- 0.0150}^{+ 0.0136},, 19 5_{- 32}^{+ 38},^{\circ})$ in the $(sin^{2} θ_{23}, δ_{CP})$ plane and $(0.58 0_{- 0.0153}^{+ 0.0140},, 2.51 5_{- 0.0344}^{+ 0.0344} \times 1 0^{- 3}, eV^{2})$ in the $(sin^{2} θ_{23}, Δ m_{31}^{2})$ plane, yielding improved joint constraints. Using GLoBES simulations together with real data, we assess how local minima of quantum correlations influence leptonic CP-violation sensitivity, $θ_{23}$ octant-degeneracy resolution, and mass-ordering determination. Our results show that minimizing entanglement can significantly affect these key sensitivities, highlighting quantum information measures as complementary probes of neutrino flavor oscillations and offering new insight into the role of quantum correlations in precision neutrino physics.
hep-phhep-exquant-ph1 citation
38
Quark and hybrid stars with renormalization group improvement of NNLO perturbative QCD
Loïc Fernandez🇫🇮 · Jean-Loïc Kneur🇫🇷 · Marcus Benghi Pinto🇧🇷 · Constança Providência🇵🇹 · Claudia Ratti🇺🇸 · Tulio E. Restrepo🇺🇸
Recently, the NNLO perturbative QCD pressure of cold and dense symmetric matter, with arbitrary quark masses, has been resummed within the renormalization-group-optimized perturbation theory (RGOPT) framework. By being imbued with renormalization group properties, the resulting pressure is less sensitive to renormalization scale ( $Λ \equiv X μ_{B} /3$ ) variations than the NNLO perturbative QCD pressure. Here, we extend this by considering $β$ -equilibrium and charge neutrality to evaluate the corresponding equation of state (EoS). We provide a compact ``pocket" fitting formula for the EoS for $N_{f} = 2 + 1$ massive quarks at different renormalization scale parameter ( $X$ ) values. We describe pure quark stars as well as hybrid stars with quark-cores. Pure quark stars compatible with astrophysical observations were obtained with $X = 3.08 - 3.58$ , whereas a larger value (4.10) is needed if the low mass object of the observation GW190814 represents a neutron star. Hybrid stars were built considering three representative hadron models based on a relativistic mean-field description, and chosen to produce soft and stiff EoSs. Stable hybrid stars with masses compatible with the massive pulsar PSR J0740+6620 were obtained considering $X$ of the order of 2 to 2.60-2.98, the largest scale giving rise to hybrid stars with a large quark core with a radius of 5 to 8 km, and the smallest to a small quark core at the center of the star.
↳ nucl-thastro-ph.HEhep-phhep-th0 citations
39
Galaxy Power Spectrum at Two-Loop Order: Implications for Weak Lensing Surveys and New Physics
Mikhail M. Ivanov🇺🇸
We compute the galaxy power spectrum at two-loop order in cosmological perturbation theory (effective field theory, EFT). We derive galaxy bias operators through the fifth order and obtain two-loop renormalization conditions for the their bias coefficients. We compute the two-loop integrals using a renormalization scheme consistent with the CLASS-PT code, allowing for an easy interface of our new computations with standard tools used in the one-loop galaxy power spectrum and bispectrum analyses. We also derive the relevant higher-derivative and stochastic contributions, and implement IR resummation using time-sliced perturbation theory. Having identified the redundant operators, we find that the two-loop galaxy power spectrum requires 21 additional EFT parameters per galaxy sample. We compare our computation with the galaxy-galaxy and galaxy-matter power spectra from the PT Challenge N-body simulation at $z = 0.61$ and find a per mille-level agreement up to $k = 0.85 h$ Mpc $^{- 1}$ . We show that even with conservative priors on all EFT parameters, the two-loop model produces an unbiased measurement of the mass fluctuation amplitude $σ_{8}$ with three times narrower error-bars than the linear theory model. The improvement over the one-loop model is $≃ 40%$ . This suggests significant gains in the two-loop EFT analyses of galaxy clustering and galaxy--lensing two-point functions ( $2 \times 2$ pt) from CMB lensing maps and imaging surveys like Euclid, LSST, and Roman. In addition, our two-loop computation offers a probe of new physics scenarios that modify the shape of the matter power spectrum at wavenumbers $(0.4 - 0.8) h$ Mpc $^{- 1}$ such as the presence of ultra-light axion dark matter sub-components with masses $m_{a} \sim 1 0^{- 24}$ eV.
↳ astro-ph.COgr-qchep-phhep-th2 citations
40
Parameterizing the Standing Accretion Shock Instability for Inference with Galactic Supernova Neutrino Signals at IceCube
Dwaipayan Mukherjee🇮🇳 · Mohamed Rameez🇮🇳 · Basudeb Dasgupta🇮🇳
Simulations of core-collapse supernovae have revealed an epoch of hydrodynamic instability in which the matter of the collapsing star undergoes quasi-periodic oscillations, known as the standing accretion shock instability (SASI). Neutrinos produced in the core of the star travel through this oscillating matter, and information about this epoch is encoded in their high-statistics event rate observable at neutrino observatories. We propose a parametrization of the SASI-modulation to study its broad features, enabling statistical inference of SASI parameters. For the benchmark Galactic supernovae considered, we show that IceCube can identify this epoch of instability and reconstruct its parameters with precision at the sub-percent level for the SASI frequency, percent level for the peak time, and a few to ten percent level for the amplitude and duration.
↳ astro-ph.SRastro-ph.HEhep-exhep-ph0 citations
41
Numerical polology: towards next-generation model-building for cosmology
Will Barker🇨🇿 · Will Handley🇬🇧 · Michael Hobson🇬🇧 · Anthony Lasenby🇬🇧 · Carlo Marzo🇪🇪 · Alessandro Santoni🇦🇹 · Leonardo Torcellini🇮🇹
The dark sector need not be restricted to simple field content. Indeed, simple bosonic configurations, such as scalar-tensor or dark photon models, contrast with the much richer picture painted by many ultraviolet scenarios. Polology is the study of propagator poles, which correspond to particle states in any given theory. We outline a numerical polology framework for discovering perturbative, ghost-free models with consistent interactions, which produces theoretical model priors by sampling the coupling space. The method is tested on tensor field theories of up to rank three. Subsequent observational constraint pipelines are illustrated for black hole superradiance (M33 X-7), dynamical dark energy (DESI DR2, Pantheon and SH0ES) and gravitational waves (GWTC-3).
↳ astro-ph.COgr-qchep-phhep-th0 citations
42
Running into tension: primordial black holes from ultra-slow-roll inflation, spectral running, and the Hubble tension
Miguel A. Sabogal🇮🇹 · Antonio J. Iovino🇦🇪 · Sunny Vagnozzi🇮🇹
Single-field ultra-slow-roll (USR) inflation is among the most studied mechanisms for primordial black hole (PBH) formation. When a non-stationary inflection point close to CMB scales is present, these models predict a negative spectral running ( $α_{s} < 0$ ), whose magnitude increases with the PBH mass. This is in tension with recent hints for positive running from Atacama Cosmology Telescope (ACT) Cosmic Microwave Background (CMB) data. However, inflationary parameters inferred from CMB data are sensitive to the assumed pre-recombination expansion history, which is precisely where new physics motivated by the Hubble tension should operate. Focusing on axion-like early dark energy (EDE) as a benchmark, we investigate the effect of such pre-recombination new physics on $α_{s}$ , and hence on the viability of USR PBH models, in light of state-of-the-art CMB data from Planck, ACT, and the South Pole Telescope, together with Baryon Acoustic Oscillation data from DESI DR2. Our analysis therefore provides an updated set of constraints on $α_{s}$ and the running of the running $β_{s}$ . For most dataset combinations, moving from $Λ$ CDM to EDE increases the inferred $α_{s}$ : once the acoustic angular scale $θ_{s}$ is fixed, EDE increases the diffusion-to-acoustic angular scale ratio $θ_{d} / θ_{s}$ , and the shift in $α_{s}$ compensates this extra damping by increasing small-scale power. In this sense, tension calls for tension: taking the Hubble tension seriously as an indication for new physics strengthens the challenges faced by USR PBH models. More broadly, our analysis stresses that inflationary model selection using CMB-inferred inflationary parameters such as $n_{s}$ and $α_{s}$ may be premature, especially until the Hubble tension, and more generally the pre-recombination expansion history, is understood.
↳ astro-ph.COgr-qchep-phhep-th8 citations
43
Charged pseudoscalar mesons in a strong magnetic field under the Weinberg model
Gaoqing Cao🇨🇳
Recent lattice QCD simulations have further validated their earlier unusual findings: The lowest energies of charged pseudoscalar mesons $π^{\pm}$ and $K^{\pm}$ decrease at stronger magnetic field, though quasiparticle approximation assumes an increasing feature. We address this long-standing puzzle by employing the chiral effective Weinberg model, in which pseudoscalar and vector mesons exhibit intrinsic mutual couplings. Under this framework, charged pseudoscalar mesons deviate from pure quasiparticle behavior due to their interactions with neutral pseudoscalar and charged vector mesons. By incorporating the modifications induced by neutral pseudoscalar-charged vector loops, we demonstrate that the lowest energies of $π^{\pm}$ and $K^{\pm}$ indeed decrease at stronger magnetic field in both the lowest- and full-Landau-level calculations. However, instabilities emerge under a fixed mesonic coupling constant, and appear unavoidable when attempting to reproduce the observed peak structures. In contrast to the quark-antiquark meson description in models such as the NJL model, our results support the conjecture that a charged pseudoscalar meson could effectively form a molecular bound state of a neutral pseudoscalar meson and a charged vector meson in the strong magnetic field regime.
↳ nucl-thhep-ph0 citations
44
The unavoidable de Sitter fate of a scale-invariant Universe
Chiara Cecchini🇮🇹 · Massimiliano Rinaldi🇮🇹
We consider a very general scale-invariant scalar-tensor theory of gravity and its flat cosmological solutions. We show that any stable configuration with non-degenerate gravitational dynamics carries a non-vanishing cosmological constant, unless the quartic self-coupling of the scalar field vanishes. Since this condition is not protected against radiative corrections, a residual cosmological constant is expected as a generic and robust prediction of this class of theories. This result suggests that dark energy may be a natural consequence of an early scale-invariant phase of the Universe.
↳ gr-qcastro-ph.COhep-phhep-thPhys.Dark Univ.(2026)·1 citation
45
Higher-order hopping-parameter expansion by human-AI collaboration
Masakiyo Kitazawa🇯🇵 · Tatsuya Wada🇯🇵
We develop efficient algorithms for evaluating higher-order terms in the hopping-parameter expansion of $Tr ln M$ on $S U (N_{c})$ gauge configurations. The resulting algorithms, which exploit a trie data structure for the computation of high-order terms, evaluate the $κ^{8}$ , $κ^{10}$ , and $κ^{12}$ terms at computational costs of approximately $20$ , $460$ , and $8900$ times that of a single staple evaluation, respectively. The correctness of the algorithms is verified by comparison with a computationally expensive but reliable reference calculation. We emphasize that collaboration between human researchers and AI coding agents was essential to the development of these algorithms.
↳ hep-lathep-ph0 citations
46
Kaluza-Klein Gravitons in a Higher Curvature Warped Geometry : A New Perspective
Abhirup Karmakar🇮🇳 · Isika Mandal🇮🇳 · Soumitra SenGupta🇮🇳
Kaluza-Klein (KK) Gravitons are the direct collider imprints of the higher dimensional bulk physics in our four dimensional universe, arising from the compactification of an extra spatial dimension. In this work, we consider a two-brane warped geometry with a 5D $f (R) = R + α R^{2}$ gravity along with cosmological constant $Λ$ . The warped spacetime provides an elegant resolution of the gauge-hierarchy problem without introducing any intermediate scale, while the Planck-scale curvature of the underlying $A d S_{5}$ bulk naturally motivates the inclusion of higher-curvature corrections. For small values of higher-curvature parameter ( $α$ ), we obtain the leading-order back-reacted warp factors perturbatively from the modified gravitational field equations. In the backdrop of a warped braneworld model, we have solved the Schrödinger-like equation governing the graviton fluctuations using a Euclidean path integral formalism, yielding the KK graviton spectrum and normalized wavefunctions directly from the corresponding quantum-mechanical propagator. Treating these results as the unperturbed background, we analytically determine the higher curvature corrections to KK graviton spectrum and their couplings to Standard Model (SM) matter fields. We find that there is an appreciable upward shift in the KK graviton masses while leaving the graviton-SM couplings only mildly modified as compared to a model with only Einstein gravity in the bulk. However the net cross-section of processes involving virtual gravitons appears to be suppressed whereas the dilepton and diphoton decay widths of the gravitons are significantly enhanced because of the higher curvature corrections. Overall, these effects lead to observable modifications to both the production and decay signatures of massive KK gravitons and may be probed in some future precision collider experiments.
↳ hep-thgr-qchep-ph2 citations
47
Stability of the Hydrogen Molecule and Related Issues
Jean-Marc Richard🇫🇷
We review the collaboration that led to the first rigorous proof of the stability of the hydrogen molecule within quantum mechanics and discuss several related issues concerning few-charge systems. Particular emphasis is placed on the role of symmetry breaking, the stability domains of Coulombic few-body systems, and some applications to exotic hadrons in the quark model.
↳ math-phhep-phmath.MP0 citations
48
Ultralight dark matter mixed with primordial black holes
Xing-Yu Yang🇰🇷
Dark matter candidates span many orders of magnitude in mass, from ultralight bosonic fields to massive compact objects. In this work, we connect these two extremes by investigating ultralight dark matter (ULDM) mixed with primordial black holes (PBHs). We study mixed ULDM-PBH halos by separating the continuum PBH contribution from the shot-noise fluctuation generated by discrete PBHs. The continuum contribution enters the averaged Schrödinger-Poisson background, while the discreteness contribution is treated as a perturbation that induces ULDM eigenmode transitions and soliton heating. The two contributions have distinct parametric dependencies: continuum effects scale with PBH fraction, whereas discreteness-driven transition rates scale with the product of PBH fraction and individual PBH mass in the perturbative regime. For a fiducial mixed halo with ULDM particle mass $1 0^{- 22} eV$ , virial mass of order $1 0^{10} M_{⊙}$ , and PBH fraction $1%$ , the continuum PBH component modifies the background density, gravitational potential, and low-lying ULDM eigenvalues only at the sub-percent level. Nevertheless, this percent-level continuum PBH contribution produces a tens-of-percent response in the coherent soliton region, changing the radial mode participation by about $20%$ . For stellar-mass PBHs, the discrete shot-noise fluctuation induces extremely slow ULDM mode transitions, with the fastest low-lying multiplet transition having a timescale of order $1 0^{9} Gyr$ for solar-mass PBHs. In this regime, the leading PBH effect is the continuum contribution, while discrete PBH shot noise is dynamically negligible on galactic timescales.
↳ astro-ph.COastro-ph.GAgr-qchep-ph0 citations
49
The geometric bookkeeping guide for $ε$ -factorised differential equations
Antonela Matijašić🇩🇪
Precision predictions for high-energy experiments rely on accurately evaluating multi-loop, multi-scale Feynman integrals in dimensional regularisation. The method of differential equations is by now the standard tool for this task, but its full power is only realised when the system can be brought into an $ε$ -factorised form. In this talk, we present an algorithmic framework that systematically constructs $ε$ -factorised differential equations for arbitrary integral families, independent of their underlying geometry. We work in the setting of twisted cohomology and study the space of differential forms associated with a given family of Feynman integrals in the Baikov representation. Our approach consists of two steps. First, we introduce a particular ordering for the Laporta algorithm that orders Feynman integrals within a sector according to their geometric properties. We observe that this order relation yields a basis whose differential equation is in a Laurent polynomial form in the dimensional regulator $ε$ . In the second step, we systematically construct transformation matrices such that the resulting system is in the $ε$ -factorised form.
↳ hep-thhep-ph0 citations

Affiliations

first authorsco-authorsvia INSPIRE