HEP Phenomenology·hep-ph

Wed·Jul 29, 2026Wednesday·July 29, 2026

51 papers—35 primary·16 cross-listed

01
Sum-Rule-Preserving Non-Factorized Transition-GPD Tomography of $N \to Δ (1232)$ Multipole Structure
R. M. Marinaro III🇺🇸
A sum-rule-preserving transition-GPD reconstruction is developed for the $N \to Δ (1232)$ electromagnetic transition. The analysis uses published CLAS $Δ (1232)$ data, including the magnetic multipole amplitude and the electric and scalar/Coulomb quadrupole ratios, together with low- $Q^{2}$ ratio-sector constraints. Magnetic, electric, and scalar/Coulomb transition amplitudes are derived and fitted with a common library of dipole, modified-dipole, $z$ -expansion, and low- $Q^{2}$ motivated candidate forms. The fitted transition form factors define the empirical momentum-transfer normalization for a family of transition GPDs constructed to preserve the measured form-factor sum rule. Factorized, correlated non-factorized, Regge-like, and double-distribution-inspired profiles are transformed into impact-parameter space to obtain transverse densities, localization radii, higher transverse-shape moments, and multipole-resolved radial kernels. The factorized baseline yields little genuine $x$ -dependent transverse localization, while the non-factorized profiles generate distinct $x$ -dependent spatial structures under the same empirical normalization. The magnetic channel provides the most stable tomography benchmark, whereas the electric and scalar/Coulomb sectors show stronger profile sensitivity. The results demonstrate that non-factorized transition-GPD tomography can extend the factorized amplitude-to-space approach while keeping the connection to measured $N \to Δ (1232)$ transition form factors.
hep-phnucl-th0 citations
02
Probing long-range $L_{e} - L_{μ}$ forces with supernova neutronization burst neutrinos
Amol Dighe🇮🇳 · Sadashiv Sahoo🇮🇳 · Manibrata Sen🇮🇳
Ultralight gauge bosons associated with flavour-dependent leptonic symmetries generate long-range potentials that can modify neutrino flavour evolution over astrophysical distances. We investigate the sensitivity of neutronization-burst neutrinos from core-collapse supernovae for such interactions in the anomaly-free $U (1)_{L_{e} - L_{μ}}^{'}$ framework. Incorporating the long-range potential into supernova neutrino oscillations, we simulate the corresponding signal in the Deep Underground Neutrino Experiment (DUNE) using a realistic detector response of its 40 kt Liquid Argon Time Projection Chamber. We show that in the range where the long-range potential dominates over or is comparable to the vacuum oscillation term, the electron-neutrino survival probability can be significantly modified. This would produce observable distortions in the time and energy distributions of the neutronization burst neutrino spectra. Our results demonstrate that future observations of galactic supernova neutrinos, particularly from a nearby event such as Betelgeuse, can provide a sensitive and complementary probe of flavour-dependent long-range leptonic interactions.
hep-phastro-ph.CO0 citations
03
Simplex Demixing: Disentangling Multiple Light-Flavor Jets at Colliders
Gregorio de la Fuente🇺🇸 · Jesse Thaler🇺🇸
Providing a practical and hadron-level definition of multiple jet flavors has been a long-standing challenge in collider physics. Previous work has introduced a data-driven, operational definition of quark and gluon jets, but no robust generalization beyond two jet categories presently exists. To address this, we introduce a machine-learning framework called "simplex demixing'' to extract $T$ jet flavors (or topics in the statistics literature) from $M$ data samples (or mixtures) with minimal constraints. Intuitively, our procedure identifies the maximally separable categories in the data, translating a multi-category classifier on the $M$ mixtures into a bounded geometric object with $T$ vertices. We first demonstrate our procedure on a toy problem to infer the truth-level fractions of down-quark, up-quark, and gluon jets from synthetic mixtures of the three pure samples. We then propose a tag-and-probe strategy to extract multiple light-flavor categories in a more realistic collider setting involving dijet production. As expected, the identifiability of jet flavors depends on their relative abundance in the samples and the hadron-level information available to the classifier architecture. Our work opens the door to data-driven extractions of multiple jet flavor properties at the Large Hadron Collider.
hep-phcs.LGhep-ex0 citations
04
Bound-state beta decay of tritium: Path to first observation and novel approach to direct neutrino mass measurement
Evgeny Akhmedov🇩🇪 · Thierry Lasserre🇩🇪 · Ferenc Glück🇩🇪 · Alejandro Saenz🇩🇪
Bound-state $β$ -decay of tritium, the process, in which the final-state electron is created in a bound atomic state of the produced $^{3} He$ atom instead of freely flying away, is predicted by the standard theory of weak interactions but has not been observed so far. We study the possibility of its experimental observation through the detection of photons from radiative decay of the excited atomic states of neutral $^{3} He$ populated by this process. We also propose a novel approach to direct neutrino mass measurement and sterile neutrino search based on accurate determination of the speed of the produced $^{3} He$ atoms through Doppler broadening of the emitted photon lines.
hep-phhep-exnucl-exphysics.atom-ph0 citations
05
Gravitational waves decay in vacuum
Diego Blas🇪🇸 · José Antonio Oller🇪🇸
We show that gravitational waves (GW), treated as coherent graviton states, decay into photon pairs in vacuum. The process, even if suppressed by $G^{2}$ , is lifted by two effects combined: the expected factor of the graviton number squared, $N^{2}$ , and the coherence of the wave. We perform the calculation describing both gravity and the photons as quantized fields, though we show that the effect admits a semiclassical description once the metric is solved to second order. We estimate the resulting rates for compact binaries and a stochastic background, including the effect from stimulated decay to the cosmic microwave background (CMB). In theories with light degrees of freedom, an analogous decay into them is also possible, and more relevant for ultralight dark matter, as it can entail huge occupation numbers. We derive first constraints on cosmological GW sources by the corresponding injection of photons from CMB spectral distortions, extragalactic backgrounds, and light-nuclei photofission. In summary, the decay of GWs into photons offers a new (challenging) handle on the detection of GW sources, and represents a new mechanism to generate other particles across cosmic history.
hep-phgr-qc0 citations
06
Multi-component Dark Matter in a Novel Three-Loop Inverse Scotogenic Seesaw Model
Asmaa Abada🇫🇷 · Nicolás Bernal🇦🇪 · A. E. Cárcamo Hernández🇨🇱 · Vishnudath K. N.🇨🇱 · Sergey Kovalenko🇨🇱 · Téssio B. de Melo🇨🇱 · Salvador Urrea🇫🇷
We consider a model which provides an explanation of the origin of light neutrino masses, the baryon asymmetry of the Universe -- via leptogenesis -- and explains the observed dark matter relic abundance with several components. In this scenario, Majorana masses of the active neutrinos are produced by the inverse seesaw (ISS) mechanism with the lepton-number-violating mass parameter being dynamically generated at three loops with a novel topology. This model is based on an extension of the Standard Model gauge symmetry by a global $U (1)^{'}$ and a discrete $Z_{2} \otimes Z_{3}$ . The latter, which is responsible for the radiative origin of the ISS lepton-number-violating parameter, survives the spontaneous breaking of the global $U (1)^{'}$ and, at the same time, ensures the stabilization of the dark sector. The lightest particles carrying non-trivial residual charges are stable, becoming potentially viable dark matter candidates. The model complies with bounds and constraints from neutrino data, collider and high-intensity charged lepton flavor-violating observables, as well as dark matter relic density and direct detection. To efficiently explore the model's high-dimensional parameter space and identify phenomenologically viable regions, we perform a global numerical scan using the MultiNest algorithm.
hep-ph0 citations
07
Coherence from interference: a solvable model of sub-GeV dark matter-nucleus scattering
Lynn Lin🇺🇸 · Tongyan Lin🇺🇸 · Momei Fang🇺🇸
How do dark matter-nucleus interactions transition from the regimes of coherent scattering, where single phonons are produced, to that of individual nuclear recoils? Answering this question relies on understanding multiphonon excitations. Multiphonons are important for interpreting low-threshold direct detection experiments, yet are computationally prohibitive to compute. In this paper, we employ a 1D $N$ -site crystal lattice model where dark matter scattering can be computed exactly. We show that the only difference between coherent and incoherent scattering is that conservation of crystal momentum is enforced in coherent scattering. The momentum conservation constraint becomes less important as more phonons are produced, yielding the transition to incoherent scattering. Using numerical calculations of the 1D structure factor, we also obtain quantitative validation of using an incoherent approximation to compute sub-GeV dark matter scattering in realistic 3D crystals.
hep-phhep-ex1 citation
08
Top-quark mass interpretation from simulation of top-flavoured mesons
Gennaro Corcella🇮🇹 · Alexander Lind🇮🇹
The interpretation of the top quark mass measurements in terms of well-known field theory definitions has been the topic of a long-standing discussion. In this paper we reconsider this issue and simulate fictitious top-flavoured mesons, whose mass can be related to any top mass definition, such as the pole mass, by means of Heavy Quark Effective Theory. We explore final-state observables for top-pair production in $e^{+} e^{-}$ and hadron collisions, and relate the top mass in standard $t t ˉ$ events to the pole mass extracted from top-meson samples simulated with Pythia 8.3. Our results are in agreement with the expectation of an uncertainty about $200$ - $300$ MeV, hence of the order of $Λ_{QCD}$ .
hep-ph1 citation
09
Beyond leading-logarithm photon production from two-loop diagrams in a hot QCD medium
Sumit🇨🇳 · Ritesh Ghosh🇹🇼 · Munshi G. Mustafa🇮🇳
We investigate high-energy photon production from a quark-gluon plasma by evaluating the imaginary part of the two-loop photon self-energies in thermal QCD. Working within the imaginary-time formalism, we derive analytical expressions for both the leading-logarithmic and the beyond-leading-logarithmic contributions to the photon production rate. The rates obtained within the thermal field theoretical framework agree with those derived from kinetic theory calculations for the relevant photon-production processes.
hep-phnucl-th0 citations
10
NNLO Determination of Polarized Parton Distribution Functions with Higher-Twist and Target-Mass Corrections
Javad Shahrzad🇮🇷 · Elliot Leader🇬🇧 · Ali Khorramian🇮🇷
We present a next-to-next-to-leading order (NNLO) QCD analysis of polarized parton distribution functions (PDFs) based on the world data set of inclusive polarized deep-inelastic scattering (DIS). The resulting PDF set, denoted as \texttt{KLS26}, includes a consistent treatment of target-mass corrections (TMCs), higher-twist (HT) contributions, and positivity constraints within a fully NNLO framework. To estimate the residual theoretical uncertainty associated with nonperturbative power corrections, both additive and multiplicative HT parametrizations are considered. Although these two approaches lead to different higher-twist coefficients, the current results yield very similar fit qualities and compatible polarized PDFs within uncertainties. The impact of NNLO corrections is assessed through a comparison with the KLSS21 polarized PDF determination at NLO, showing the most visible changes in the polarized strange-quark distribution, together with moderate modifications in the gluon sector and smaller effects in the up- and down-quark helicity distributions. Additional fits treating the nonsinglet axial charges as free parameters, together with different higher-twist implementations, induce small but flavor-dependent modifications in the PDFs, with the most noticeable effects in the polarized strange-quark distribution and moderate sensitivity in the gluon. The \texttt{KLS26} set establishes an updated determination of helicity-dependent parton distributions, enabling future precision studies of nucleon spin structure.
hep-phhep-exhep-lat0 citations
11
Regarding the Rotational Unruh Effect
A. Deur🇺🇸 · S. J. Brodsky🇺🇸 · C. D. Roberts🇨🇳 · B. Terzi{ć}
We study the rotational Unruh effect by identifying the pseudodynamics which emerges when fundamental spacetime symmetries are violated. We show that there is, fundamentally, no rotational Unruh effect, in agreement with the first explicit calculations of the literature, and that, when such an effect has been claimed to exist in later articles, its origin traces back to the derivation of the standard Unruh effect involving linear acceleration. Such a linear Unruh effect intrudes because the chosen reference frames do not respect the cylindrical symmetry of the system, and thus the analyses require Lorentz boosts. Our study also confirms previous findings that the Unruh effect is a consequence of the pseudodynamics which arises because Instant-Form dynamics explicitly breaks a fundamental symmetry of spacetime: Poincaré invariance.
hep-phgr-qc1 citation
12
Searches for heavy neutral lepton decays at spallation neutron sources
Valentina De Romeri🇪🇸 · A. Galindo-Uribarri🇺🇸 · Ana Martín-Galán🇪🇸 · Víctor Martín Lozano🇪🇸 · G. Sanchez Garcia🇲🇽
Spallation neutron sources provide intense neutrino fluxes from pion and muon decay at rest, with energies in the few tens of MeV range. Experiments such as COHERENT exploit these fluxes to detect neutrinos via coherent elastic neutrino $-$ nucleus scattering (CE $ν$ NS). However, these facilities also offer a unique opportunity to produce and probe light, secluded, or weakly $-$ coupled particles. In this work, we investigate the sensitivity of the Spallation Neutron Source at the Oak Ridge National Laboratory to heavy neutral leptons (HNLs) in the MeV $-$ GeV mass range, as a case study. We consider HNL production in pion and muon decays at rest, followed by their decay into visible Standard Model particles within the detector volume. We analyze a range of current and proposed COHERENT detectors and evaluate their sensitivity to HNL mixing with muon and electron neutrinos, as well as to scenarios with mixed mixing. We find that existing detectors can set meaningful constraints, particularly for muon $-$ flavor mixing, while future ton $-$ scale realizations can probe previously unexplored regions of the parameter space. We further discuss prospects at other relevant spallation source facilities and comment on the complementarity of their projected sensitivities. Our results demonstrate that CE $ν$ NS experiments at spallation neutron sources provide a powerful, complementary avenue for new physics searches beyond their primary role as neutrino detectors.
hep-ph0 citations
13
Few-gluon interactions and multipole radiation in high energy nuclear collisions
Thomas A. Trainor🇺🇸
Broad claims have been made over years about achievement of quark-gluon plasma (QGP) formation in high-energy heavy-ion collisions based on certain phenomena anticipated for QGP formation. More recently, similar phenomena have appeared in smaller collision systems. In response, the original narrative associated with QGP formation has been altered, with introduction of novel concepts such as ``QGP droplets'' appearing even in p-p collisions. In contrast, alternative research has revealed novel aspects of p-p and p-Pb collisions such as exclusivity for N-N interactions and consequences of time dilation for interacting partons. Collision geometry for A-B collisions has also been shifted from conventional Glauber Monte Carlo simulations (strongly biased) to inversion of ensemble-mean $p ˉ_{t}$ data. The present study demonstrates that jet production dominates all aspects of $p_{t}$ spectrum structure and minimum-bias angular correlations over the full $p_{t}$ range of accessible data. Recently, progress has been made on interpretation of azimuth quadrupole ( $v_{2}$ ) data, reexpressed in terms of total correlated-pair number as an extensive measure, leading to inference of quadrupole $m_{t}$ spectra and quadrupole amplitude variation across all A-B collision systems that show strong indication of the effects of exclusivity. The same approach applied to jet angular correlations shows similar trends. A comprehensive quantitative description of the two QCD phenomena across all collision systems has emerged. The underlying processes are few-gluon interactions producing characteristic correlation structures corresponding to color-dipole (two-gluon, dijet) and color-quadrupole (three-gluon) radiation. That description does not rely on any role for a dense medium, multiple scattering, QGP droplets or hydro theory. It applies the same rules uniformly to small and large collision systems.
hep-phnucl-th0 citations
14
Quantum detection of CP violation in the $t t ˉ$ system: production
Priyanka Lamba🇧🇪 · Fabio Maltoni🇧🇪 · Olimpia Miniati🇮🇹 · Eleni Vryonidou🇬🇧
We investigate how possible new CP-violating top-quark interactions are encoded in the quantum state of a produced $t t ˉ$ pair. We derive analytic expressions for the production density matrix in several benchmark channels relevant to hadron, lepton and photon colliders. In a common spin basis, we identify two characteristic CP-odd structures in the Fano--Bloch decomposition: a difference between the top and antitop polarisation vectors and an antisymmetric component of the spin-correlation matrix. We construct observables that directly probe these structures and study how quantum information measures, including discord, concurrence, magic and trace distance, respond to CP-even and CP-odd SMEFT contributions. Finally, using current measurements and future collider projections, we assess the sensitivity of these observables to possible new sources of CP violation in top-quark production. This establishes the production-level framework whose experimental reconstruction is developed in a companion paper.
hep-phhep-exhep-thquant-ph2 citations
15
Quantum detection of CP violation in the $t t ˉ$ system: tomography
Priyanka Lamba🇧🇪 · Fabio Maltoni🇧🇪 · Olimpia Miniati🇮🇹 · Eleni Vryonidou🇬🇧
We develop a quantum-tomographic framework for determining whether possible CP-odd effects in $t t ˉ$ events originate in production, in decay, or in both. In the narrow-width approximation, the process $I \to t t ˉ \to b ℓ^{+} ν b ˉ ℓ^{-} ν ˉ$ factorises into a production density matrix and top and antitop decay density matrices. We extend the standard tomography procedure to a general anomalous $W t b$ vertex and derive the corresponding angular distributions. Polar-angle distributions retain their usual tomographic form, up to modifications of the spin-analysing powers, and can therefore be used to reconstruct the production density matrix and test its CP properties. By contrast, dedicated azimuthal observables involving the $b$ --lepton decay planes contain characteristic sine modulations that provide linear probes of possible new CP-violating interactions in the decay vertex. Combining the two classes of observables gives a systematic strategy for separating sources of CP violation in production and in decay. We illustrate the resulting angular signatures for representative $t t ˉ$ production scenarios at hadron and lepton colliders.
hep-phhep-exhep-thquant-ph2 citations
16
Spin resummation of heavy quarkonium photoproduction: from the gluonic gravitational form factors to the holographic pomeron
Kiminad A. Mamo🇺🇸 · Kemal Tezgin🇺🇸 · Christian Weiss🇺🇸
Exclusive heavy quarkonium photoproduction probes the proton's gluonic structure from near-threshold (fixed-spin exchanges, gravitational form factors) to high energies (reggeized dynamics). We construct a holographic QCD amplitude that resums the even spin- $j$ gluonic exchanges, with the spin-2 input fixed by lattice QCD GFFs. The new framework describes the $J / ψ$ cross section from JLab to HERA energies in a unified manner. It explains why the spin-2 exchange model for GFF extraction near threshold is not a controlled approximation and suggests how to improve it.
hep-phhep-thnucl-th0 citations
17
One-loop HDL thermodynamics of a strongly magnetized isospin asymmetric cold quark matter
Salman Ahamad Khan🇮🇳 · Sarthak Satapathy🇮🇳 · Sumit🇨🇳
We have computed the longitudinal pressure and magnetization of strongly magnetized cold QCD matter in the presence of both quark and isospin chemical potentials using the hard-dense-loop perturbation theory (HDLpt). For that purpose, we have first obtained the resummed quark and gluon propagators in the presence of a strong magnetic field and isospin density. We have found that pressure gets monotonically enhanced with both chemical potentials. Magnetization is found to be positive, which indicates the paramagnetic nature of the cold quark matter. We also discuss the resulting pressure anisotropy, where the transverse pressure is suppressed relative to the longitudinal pressure in the strong-field regime.
hep-ph0 citations
18
Beyond a symmetry-restricted VEV ansatz: transverse stability of an $S U (5)$ special-subgroup vacuum
Hidetoshi Kawase🇯🇵
Extended Higgs sectors can realize multistage breaking chains in grand unified theories (GUTs), and the resulting intermediate gauge phases can be relevant to cosmological defects. Restricting vacuum expectation values (VEVs) to configurations that preserve a chosen subgroup is an efficient way to identify candidate stationary points, while their stability against fluctuations outside this subspace is a separate question. We study this question in a renormalizable $S U (5)$ GUT Higgs sector with an adjoint $2 4_{H}$ and a complex symmetric $1 5_{H}$ , motivated by a special-subgroup realization of Langacker-Pi monopole erasure. On the standard adjoint background, the $1 5_{H}$ VEVs that preserve the intermediate gauge group form a two-block family with independent color- and weak-block amplitudes. Portal interactions can make these amplitudes unequal without changing the unbroken gauge group. Two independent mixed quartic invariants become identical when evaluated on this two-block field space, although they contribute differently to color-weak fluctuations. We derive the complete spectrum of these modes and identify two bounded-from-below parameter choices that induce the same potential on the two-block field space but have different curvatures in transverse directions. The common stationary configuration is a local minimum in one case and a saddle with six negative physical modes in the other. Direct Hessian calculations in the full 54-dimensional real scalar field space reproduce the analytic spectrum and verify both the minimum-saddle distinction and locally stable benchmark vacua.
hep-ph0 citations
19
A quark-diquark model for parity doublet structure of baryons
Bikai Gao🇯🇵 · Masayasu Harada🇯🇵
The chiral invariant mass of baryons is a phenomenological input of parity doublet models, and its microscopic origin remains an open question. We propose that the chiral invariant mass and the parity doublet structure originate from the diquarks: the scalar ( $0^{+}$ ) and pseudoscalar ( $0^{-}$ ) diquarks form a parity doublet whose invariant mass is generated by gluon dynamics rather than by the quark condensate. We construct a three-flavor chiral quark--diquark model in which a quark and a diquark are bounded into a baryon through a chiral-invariant four-body interaction whose structure is reduced from one-gluon exchange. It is shown that the quark--diquark structure automatically yields the two chiral representations and the mirror assignment of the parity doublet model, and the composite baryons acquire chiral invariant masses even for massless quarks. We find that the octet baryon spectrum and the nucleon sigma terms are reproduced very well with a minimal set of parameters. Furthermore, after chiral symmetry restoration, the model predicts a distinctive inverted mass hierarchy: the nucleon remains relatively heavy, whereas the $Σ$ and $Ξ$ baryon become lighter than the nucleon. This inverse mass ordering may therefore provide a novel, experimentally testable signature towards chiral symmetry restoration.
hep-phnucl-th0 citations
20
Heavy Jet Mass in Hadronic Higgs Decays
Luen Clingerman🇺🇸 · Xiaoyuan Zhang🇺🇸
The heavy jet mass distributions in hadronic Higgs decays are computed to next-to-next-to-next-to-leading logarithmic order (N $^{3}$ LL $^{'}$ ) in the dijet limit and NNLL in the trijet limit, matched to the next-to-next-to-leading order (NNLO). Both resummation results are obtained from the factorization theorems in Soft-Collinear Effective Theory. In particular, we study the Sudakov shoulders in the trijet region, originating from the incomplete cancellation of infrared singularities between final states with different parton multiplicities, and resum the induced large logarithms to all orders. The shoulder resummation yields sizable corrections and improves the perturbative stability of the distribution. Our results provide state-of-the-art predictions for heavy jet mass in $H \to g g$ and $H \to q q ˉ$ and can be applied to precision Higgs measurements at future $e^{+} e^{-}$ colliders.
hep-phhep-ex0 citations
21
Isolating Scheme Dependence of Quasi-PDFs in the RI/MOM Scheme
Junegone Chay🇰🇷
Quasi-parton distribution functions provide a framework for relating lightcone parton distributions to correlation functions in Euclidean lattice QCD. Their connection to lightcone distributions is established through perturbative matching, whose form depends on the renormalization prescription adopted for the quasi-PDF. In the ordinary RI/MOM scheme, the off-shell reference momentum enters both the renormalized quasi-PDF and the matching coefficient. We propose modified finite renormalization schemes in which neither quantity depends on the RI/MOM reference momentum. Starting from the ordinary RI/MOM scheme, we identify the part to be retained in the renormalized quasi-PDF and include the remaining finite part in the counterterm. We consider a minimal RI/MOM scheme and a modified minimal scheme as specific examples. We derive the corresponding one-loop renormalized quasi-PDFs, counterterms, matching coefficients, and renormalization-group equations, and show explicitly that the finite transformation removes the dependence on the RI/MOM reference momentum from both the renormalized quasi-PDF and the counterterm in the modified schemes.
hep-phhep-lat0 citations
22
Spatial Guidance Field Theory: From Gradient Postulates and Charge Conservation to Gauge Group Structure
Xinqiao Li🇨🇳
We construct a unified framework for interactions from three postulates: (1) all elementary forces arise as gradients of guidance potentials, (2) the charges that generate these potentials are conserved, and (3) the internal symmetry group must accommodate chiral fermions. The chirality postulate forces the internal symmetry group to be non-Abelian. In the non-relativistic limit, a scalar guidance field reproduces Newtonian gravity and Coulomb's law, and relativistic consistency upgrades the potentials to a spacetime metric and gauge vector fields. The central result is a rigorous derivation that the internal symmetry group must be a compact Lie group; combined with anomaly cancellation and minimal rank and representation content, this uniquely selects the Standard Model's $S U (3)_{c} \times S U (2)_{L} \times U (1)_{Y}$ . We present a guidance-field description of strong and weak interactions, and derive coupling-modified Tolman--Oppenheimer--Volkoff equations for neutron stars, obtaining a theoretical maximum mass of $M_{max}^{th} \approx 2.8 \pm 0.4 M_{⊙}$ , naturally accommodating the $2.6 M_{⊙}$ companion of GW190814. We further derive quantitative predictions for equivalence principle violation from nonlinear superposition of guidance potentials, with a QCD-scale benchmark within reach of next-generation experiments. Finally, we discuss implications for black hole interiors within a geometric framework in which charges are topological invariants of a generalized space, and provide the mathematical formulation of the total connection, its action functional, and field equations.
hep-ph0 citations
23
Singly heavy tetraquarks
Jun-Jie Liu🇨🇳 · Zhi-Biao Liang🇨🇳 · Feng-Xiao Liu🇨🇳 · Mu-Yang Chen🇨🇳 · Xian-Hui Zhong🇨🇳 · Qiang Zhao🇨🇳
In this work, we carry out a systematic study of the spectra of the $1 S$ -wave states for the whole singly-heavy tetraquark systems within a semi-relativistic hybrid quark potential model, in which both the one-gluon exchange (OGE) and one-boson exchange (OBE) interactions are included. Furthermore, the fall-apart decays are evaluated with the quark exchange model by combining the obtained spectra. It is found that besides the OGE potentials, the OBE potentials play crucial roles for describing the spectrum. All of our obtained states lie far above the lowest dissociation meson-meson threshold. They are compact states with relatively narrow fall-apart widths $\sim 1 - 120$ ~MeV. The $D_{s 0} (2317)$ , $D_{s 1} (2460)$ , $T_{b s ˉ} (5568)$ , and $T_{c s ˉ} (2327)$ resonances reported from experiments cannot be explained as compact tetraquarks. While the $T_{c ˉ s ˉ 0} (2870)$ and $T_{c s ˉ 0} (2900)$ favor the tetraquark states with $I J^{P} = 0 0^{+}$ and $1 0^{+}$ , i.e. $T_{(c ˉ s ˉ [u d]) 0^{+}}^{0} (2919)$ and $T_{(c n {s ˉ n ˉ}) 0^{+}}^{1} (2922)$ , respectively. More singly-heavy tetraquark states have good potentials to be observed in some of their dominant decay channels in experiments.
hep-ph0 citations
24
Distinguishing the Axion-Wind and Oscillating-EDM Couplings in Storage-Ring Searches for Axion Dark Matter
V. Hejny🇩🇪 · J. Pretz🇩🇪
Resonant spin-precession experiments in storage rings are sensitive to two distinct axion and axion-like particle dark-matter couplings: an oscillating electric dipole moment (EDM) primarily driven by the axion-gluon interaction, and the axion-wind (derivative) coupling acting as an effective pseudomagnetic field on the spin. Both effects produce a vertical polarization buildup at the same resonance frequency and are therefore degenerate in this standard observable. It is shown that the two couplings enter the vertical build-up and the spin-precession phase walk as the difference and sum of their resonance strengths, respectively. Measuring both observables simultaneously at fixed energy in a multi-bunch configuration allows the individual coupling strengths to be extracted up to a two-fold sign ambiguity. As a complementary approach, the ratio of electric to magnetic bending fields in a combined storage ring can be varied while keeping the resonance frequency fixed. This leaves the axion-wind contribution unchanged while modifying the EDM contribution in a calculable way, enabling a clean separation of the two effects. Both approaches can be used in future storage-ring facilities dedicated to EDM measurements.
hep-phhep-exphysics.acc-ph0 citations
25
Photon Gas Thermodynamics in Doubly Special Relativity at the Planck Scale
Qi Xiong🇨🇳 · Xinyi Yang🇨🇳 · Guifeng Su🇨🇳 · Yi Zhang🇨🇳
We investigate the thermodynamics of a photon gas within the Magueijo-Smolin formulation of doubly special relativity, a framework that augments the speed of light with an observer-independent energy scale of the order of the Planck energy. We derive the logarithmic grand partition function, and the complete set of thermodynamic quantities for the photon gas, including the Helmholtz free energy, internal energy, entropy, pressure, and heat capacity, and perform their numerical evaluation. Our results smoothly reduce to the conventional special relativistic expressions in the limit where the invariant energy scale tends to infinity. For temperatures approaching the Planck scale, the finite cutoff induces a systematic suppression of all thermodynamic functions relative to their standard special-relativistic counterparts.
hep-phhep-th1 citation
26
Pseudoscalar Yukawa Coupling Induced Helical Asymmetry in Fermionic Preheating
Ke FU🇨🇳 · Li-Shuang Liu🇨🇳 · Yu-Feng Wang🇨🇳 · Xin-Yu Gu🇨🇳 · Xi-Bin Li🇨🇳
In this study, we investigate the fermionic helical asymmetry during preheating by introducing a model in which the Dirac field $ψ$ couples to the scalar inflaton $ϕ$ directly through the pseudoscalar Yukawa mechanism described by the term $- g \frac{ϕ}{f} m_{ψ} ψ ˉ i γ^{5} ψ$ . Following inflation, as the inflaton oscillates around the minimum of its potential, the effective frequency of Dirac field changes non-adiabatically, resulting in particle production. These oscillations also indicate that the pseudo-mass $m_{5} = g ϕ m_{ψ} / f$ changes the sign, leading to the production of helical-asymmetric fermions. We employ the WKB method to analytically calculate the transition relations of the Bogoliubov coefficients, which is valid for an arbitrary number of productions and demonstrates a significant difference compared to the case without asymmetry. In the expanding universe, the presence of pseudo-mass $m_{5}$ alters the Gaussian distributions for each helical state, since the combined effects of Pauli blocking and parametric resonance produce coherent enhancement and coherent suppression in certain frequency ranges. This departure arises from the imaginary component of the first-order adiabatic complex phase, denoted as $Θ_{1}^{(r)}$ . The real part of $Θ_{1}^{(r)}$ significantly enhances the number density of each helical state after eight oscillations of the inflaton since the coherent superposition. These conclusions have also been validated by the numerical results.
hep-phgr-qc0 citations
27
Virtual state and two-pole structure: $Ξ (1690)$ and $Ξ (1820)$ from BESIII data on $ψ (3686) \to K^{-} Λ Ξ ˉ^{+}$
Jun He🇨🇳
We investigate the nature of the $Ξ (1690)$ and $Ξ (1820)$ resonances by analyzing the recent BESIII data on $ψ (3686) \to K^{-} Λ Ξ ˉ^{+}$ within a coupled-channel rescattering framework. The calculation includes the channels $K ˉ Λ$ , $K ˉ Σ^{(*)}$ , $π Ξ^{(*)}$ , $η Ξ^{(*)}$ , and $K Ω$ . A direct fit to the data reveals that the $Ξ (1690)$ is best described as a virtual state located right below the $K ˉ Σ$ threshold, a feature that naturally explains its very sharp peak observed in the $K^{-} Λ$ invariant mass spectrum. In contrast, the $Ξ (1820)$ exhibits a two-pole structure originating mainly from the coupled contributions of the $K Σ^{*}$ and $π Ξ^{*}$ channels, showing a two-pole pattern similar to that of the well-known $Λ (1405)$ and accounting for the unexpectedly broad width measured by BESIII. These findings provide new insights into the dynamical generation of hyperon resonances and highlight the importance of high-precision data from charmonium decays.
hep-ph1 citation
28
Constraining axion quadratic couplings with the Hulse-Taylor binary system
Ziwen Yin🇨🇳 · Shyam Balaji🇬🇧 · Malcolm Fairbairn🇬🇧 · David J. E. Marsh🇬🇧
The orbital evolution of the Hulse-Taylor binary neutron star system is described to high precision by general relativity, in which gravity is the only long-range force and gravitational waves provide the dominant energy-loss channel. We use this precision test of relativistic binary dynamics to derive new constraints on axion couplings to stable neutron star constituents: neutrons, electrons, and muons. Quadratic shift symmetry breaking axion-fermion couplings allow binary systems to lose energy through dipole and quadrupole emission of axion waves. These couplings also mediate long range, spin independent forces in two different regimes: in an ambient dark matter background, and when a tachyonic phase transition is triggered inside the neutron stars. For light QCD axions our constraints can be recast as limits on the axion decay constant, which are complementary to other probes for $m_{a} ≲ 1 0^{- 12} eV$ and $f_{a} ≲ M_{pl}$ . For $m_{a} ≲ 1 0^{- 12} eV$ , we place, to our knowledge, the strongest available constraint on the quadratic axion--muon coupling scale, providing a complementary probe to supernova cooling.
hep-ph0 citations
29
The 95 GeV Excess in Models with Two Higgs Doublets plus One Singlet: Model Distinction via Four-top Final States and Triple Higgs Couplings
S. Heinemeyer🇪🇸 · C. Li🇨🇳 · G. Moortgat-Pick🇩🇪 · D. Schieber🇩🇪
We investigate the prospects for experimentally distinguishing the Next-to-Two-Higgs-Doublet Model (N2HDM) and the Two-Higgs-Doublet Model with a Complex Singlet (2HDMS) in the Yukawa type II realization. Both models can successfully accommodate the reported Higgs-boson excesses around 95 GeV while satisfying current theoretical and experimental constraints, leading to very similar predictions for the observed Higgs spectrum and signal strengths. We analyze how they can nevertheless be discriminated through observables sensitive to the scalar potential and the CP-odd sector. Analytical expressions for the trilinear Higgs couplings are derived, exhibiting characteristic contributions induced by the additional cubic interactions of the 2HDMS. We study the corresponding phenomenology in two complementary collider environments: four-top production at the High-Luminosity LHC, probing the different pseudoscalar sectors. In a second step we analyze Higgs pair production at a future high-energy $e^{+} e^{-}$ collider, providing direct sensitivity to the trilinear Higgs couplings. We quantify the potential to distinguish the two models by introducing the minimum deviation from the N2HDM limit required for a $2 σ$ difference between the two models. Although our numerical analysis focuses on benchmark scenarios describing the 95 GeV excesses, the proposed approach provides a general framework for discriminating between singlet-extended Higgs sectors at future colliders.
hep-ph0 citations
30
Compositeness relations for near-threshold p-wave bound states
Guo-Ying Chen🇨🇳
We generalize Weinberg's compositeness relations to near-threshold p-wave bound states and derive the relations between the p-wave effective range expansion parameters, binding energy B, and the field renormalization constant Z. We also provide the corresponding Feynman rules which are appliecable regardless of whether the near-threshold state is a pure molecular state or an elementary multiquark state.
hep-phhep-exnucl-th1 citation
31
Heavy and heavy-light mesons with arbitrary spin and parity in the Covariant Spectator Theory
Alfred Stadler🇵🇹 · Elmar P. Biernat🇵🇹
This work generalizes the one-channel Covariant Spectator Theory (CST) formalism to describe quark-antiquark mesons of arbitrary spin-parity $J^{P}$ . We also improve the quark-antiquark interaction kernel by incorporating the momentum dependence of the strong coupling. Within this framework, we perform global fits to the masses of experimentally established heavy and heavy-light mesons with $J^{P} = 0^{\pm}, 1^{\pm}, 2^{\pm},$ and $3^{\pm}$ . With only eight adjustable parameters, the model yields an excellent global description of the observed quark-antiquark spectrum and predicts both unmeasured states and likely $J^{P}$ assignments for states with unconfirmed quantum numbers. In particular, our results support the identifications of the recently observed $B_{c} (1 P)^{+}$ candidates as $0^{+}$ , $1^{+}$ , and $2^{+}$ states, and the $B_{c}^{*+}$ as the lowest $1^{-}$ state in the bottom-charm sector, as well as the $D_{s 1} (2933)^{+}$ as axial-vector state in the charm-strange sector.
hep-phnucl-th1 citation
32
A dispersive method to study CP asymmetries in hadronic multi-body $B$ decays
L. A. Heuser🇩🇪 · A. Reyes-Torrecilla🇪🇸 · C. Hanhart🇩🇪 · Y. Huang🇩🇪 · B. Kubis🇩🇪 · P. C. Magalhães🇧🇷 · T. Mannel🇩🇪 · J. R. Peláez🇪🇸
We present the details of a dispersive method to construct the amplitudes for hadronic multibody $B$ decays based on the universality of pairwise hadronic final-state interactions at low invariant masses. This approach allows us to split the amplitude into source terms controlled by phenomenological parameters and final-state interactions, governed by the precise knowledge of two-body dynamics, both resonant and non-resonant. As a concrete application, we make use of the well-determined low-energy pion-pion ( $π π$ ) interactions to understand the enhanced localized CP violation observed in $B^{\pm} \to K^{\pm} π^{+} π^{-}$ . Fitting only angle-integrated CP-asymmetry data, the method successfully predicts the Dalitz plot differential distribution of events and of the CP asymmetry in the low-energy region. This allows for a better understanding of the large localized CP asymmetry recently reported by LHCb, which is shown not to be driven by an absolute enhancement of CP-violating effects, but by a suppression of the CP-conserving part resulting from the interplay of several partial waves. Moreover, we show that the widely-neglected non-resonant isospin-2 contributions play an essential role in the description of CP violation in this system. The method can be straightforwardly adapted to other multibody decays, where final-state two-hadron interactions drive the CP violation.
hep-phhep-ex3 citations
33
Form factors of the $ρ$ -meson in chiral perturbation theory
Kakha Shamanauri🇩🇪 · Jambul Gegelia🇩🇪 · Ulf-G. Meißner🇩🇪 · Akaki Rusetsky🇩🇪
We present the calculation of the electromagnetic form factors of the $ρ$ -meson at one loop in Chiral Perturbation Theory. The power-counting-violating terms in the loop diagrams are subtracted by using infrared regularization, and the Ward identities are explicitly verified at the order considered. The results are compared to the recent calculations carried out in the framework of non-relativistic effective field theory.
hep-phhep-latnucl-th0 citations
34
Probing the limits on anomalous quartic gauge couplings via $Z Z γ$ production in the $ℓℓ ν ν γ$ channel at FCC-hh
A. Yilmaz🇹🇷 · A. Senol🇹🇷 · H. Denizli🇹🇷 · I. Turk Cakir🇹🇷 · O. Cakir🇹🇷
In this study, the sensitivity to anomalous quartic gauge couplings (aQGCs) is projected via $pp \to Z Z γ$ production in the 100 TeV proton-proton Future Circular Collider - hadron-hadron (FCC-hh) for an integrated luminosity of 30 ab $^{- 1}$ . The $ℓℓ ν ν γ$ final state under consideration consists of a same-flavor, opposite-sign lepton pair (electrons or muons) from one $Z$ boson, the invisible decay of the other $Z$ boson into neutrinos, and an accompanying photon. The FCC-hh detector response and its effects on the reconstructed objects are included through a realistic detector simulation. Three multivariate techniques are employed to separate the signal from the relevant SM backgrounds. Unitarity is preserved by a strict, operator-dependent bound on the total transverse mass ( $M_{T}^{t o t}$ ) of the system. The median expected significances are calculated within the Asimov approximation for one anomalous coupling varied at a time and for background systematic uncertainties between 0\% and 10\%. The highest separation power is obtained with the deep neural network method. The resulting 95\% confidence level limits on $∣ f_{T 0} / Λ^{4} ∣$ , $∣ f_{T 8} / Λ^{4} ∣$ , $∣ f_{T 9} / Λ^{4} ∣$ and $∣ f_{M 2} / Λ^{4} ∣$ in the combined $e + μ$ channel without systematic uncertainties are $2.83 \times 1 0^{- 3}$ , $1.65 \times 1 0^{- 3}$ , $3.81 \times 1 0^{- 3}$ and $8.97 \times 1 0^{- 3}$ TeV $^{- 4}$ , respectively. We have an order of magnitude improvement when compared to current LHC limits with the assumption of 5\% systematic uncertainty.
hep-ph0 citations
35
Probing Lepton-Flavor-Violating Four-Lepton Operators at a Muon Collider
Sukanta Dutta🇮🇳 · Purnath Unnikrishnan🇮🇳 · Yashasvi🇮🇳
We investigate charged lepton-flavour violation (LFV) induced by dimension-six four-lepton operators within the Standard Model Effective Field Theory at a proposed high-energy muon collider. We study the processes $μ^{+} μ^{-} \to e^{\pm} τ^{\mp}$ , $μ^{+} μ^{-} \to e^{\pm} μ^{\mp}$ , and $μ^{+} μ^{-} \to μ^{\pm} τ^{\mp}$ at $s = 3$ , $10$ , and $14$ ~TeV, incorporating beam polarisation and hadronic $τ$ reconstruction. Using an optimal-observable analysis of the angular distributions, we perform a global fit to the relevant set of four-lepton operators. Projected sensitivities reach $C / Λ^{2} \sim (0.6$ - $1.6) \times 1 0^{- 11} GeV^{- 2}$ , depending on the flavour and chiral structure of the operator, exceeding current limits by up to an order of magnitude. A combined analysis of multiple centre-of-mass energies and beam polarisations significantly improves the resolution of correlations among the Wilson coefficients. These results highlight the strong sensitivity of a future multi-TeV muon collider to charged lepton flavour violating four-lepton interactions, establishing it as a powerful probe of the SMEFT parameter space.
hep-phhep-ex0 citations
36
A Difference Operator Approach to Quantum Random Walks: Parseval Identity, Krawtchouk Matrices, and Hermite Limits
Chien-Wen Hwang
We introduce a discrete difference operator D_k to study the one-dimensional quantum random walk (QRW) with the Hadamard coin. Explicit combinatorial expressions are obtained for the probability amplitudes a(n,k) and b(n,k), which encode the final step direction and carry alternating signs that reflect the merging of leftward steps. Removing these signs and the coin-state distinction recovers the classical binomial distribution. The symmetric and antisymmetric combinations $a \pm b$ are shown to coincide with diagonal and sub-diagonal entries of the Krawtchouk matrix. Using cross identities among Krawtchouk matrix elements, we prove by induction that the amplitudes satisfy a Parseval identity sum (a^2+b^2)=2^n-1, establishing probability conservation in the Krawtchouk formulation. The operator D_k acts as a discrete Hermite polynomial generator: the ratios h_m = (n choose k)^{-1} D_k^m (n choose k) admit explicit closed forms and converge to Hermite polynomials in the continuous limit. At the discrete level, D_k connects successive Krawtchouk matrices and acts as a coherence generator and a raising operator. The h_m quantify the position-dependent degree of quantum interference on both halves of the distribution, either individually (for x >= 0) or through an inverse-Pascal combination of several h_m (for x < 0), and the ballistic O(n^2) scaling of the variance emerges from the superposition of all excited states. Numerical illustrations for n=6 and n=10 corroborate the analytical results.
↳ quant-phhep-phmath-phmath.MP0 citations
37
TempLat: a versatile C++ engine for lattice field theories
Adrien Florio🇩🇪 · Franz R. Sattler🇩🇪
We present TempLat, a C++ framework for lattice field theory simulations in arbitrary dimensions. Its symbolic language, built on expression templates, translates mathematical expressions almost verbatim into C++ while compiling to highly optimized kernels, in contexts ranging from classical-statistical to Monte Carlo simulations. TempLat is performance-portable: building on Kokkos, it supports large CPU clusters, as well as NVIDIA and AMD GPUs. Its abstraction of hardware into a device concept makes TempLat extensible to future architectures. We demonstrate excellent strong and weak scaling on both CPUs and GPUs. We also present ParaFaFT, a standalone parallel discrete Fourier transform library supporting arbitrary dimensions on all of the above hardware, and benchmark its scaling. Both are open source and available on GitHub, and power a new release of CosmoLattice, a widely used early-universe simulation library now available on GPUs.
↳ hep-latastro-ph.COcond-mat.stat-mechhep-ph2 citations
38
Correlated signals of ultralight scalar dark matter in pulsar timing
Joshua W. Foster🇺🇸 · Kimberly K. Boddy🇺🇸 · Jeff A. Dror🇺🇸 · Vincent S.H. Lee🇺🇸 · Andrea Mitridate🇩🇪 · Tristan L. Smith🇺🇸 · Kelsie Taylor · Tanner Trickle🇺🇸
Pulsar timing arrays (PTAs) are sensitive to ultralight dark matter (ULDM) in the $1 0^{- 24}$ - $1 0^{- 20} eV$ mass range, with existing datasets already probing otherwise open parameter space and future PTAs promising substantial improvements in reach. Thus far, however, PTA searches for ULDM have typically been formulated using limiting descriptions. Analyses are performed in either the fully correlated limit, in which the local ULDM amplitude is shared across the array, or the fully uncorrelated limit, in which each pulsar has an independent local amplitude. Because the transition between these regimes occurs within the PTA-sensitive mass range, projected sensitivities and data-derived constraints can depend on which limiting description is assumed. For the first time, we develop a self-consistent analysis that treats the ULDM field as a Gaussian random field with finite spatial correlations, allowing the amplitude prior used in PTA signal models to interpolate continuously between the fully correlated and fully uncorrelated limits. We apply the framework to both linearly and quadratically coupled scalar ULDM, the latter including the universal gravitational signal sourced by the oscillating ULDM pressure. Pulsar-distance uncertainties are incorporated through an augmented latent-field prior, and the resulting distance-marginalized latent-amplitude distribution is represented with a normalizing-flow surrogate. We validate the method on mock PTA datasets, including blinded signal injection tests.
↳ astro-ph.COgr-qchep-ph0 citations
39
The Tachyon Chern-Simons action with a generic tachyon field, and baryons in V-QCD
Jean-Loup Raymond🇫🇷 · Matti Järvinen🇨🇳 · Elias Kiritsis🇫🇷 · Francesco Nitti🇫🇷 · Edwan Préau🇳🇱
Consistency with global flavor anomalies requires the presence of Chern-Simons terms in holographic models of QCD. Such terms are analyzed in a setup arising in the holographic V-QCD model, where chiral symmetry breaking is implemented through the condensation of a complex scalar field, the tachyon. Using the superconnection formalism, the Tachyon-Chern-Simons terms are constructed explicitly in the general case, where the tachyon is any complex matrix in flavor space. This general case covers, among other things, backgrounds where different quark flavors have different masses. These new results are used to analyze the structure of the baryon solutions in the presence of nonzero quark masses. Expressions for the baryon number current and the total baryon number are found, and the baryon number is shown to be equal to the topological instanton number of the baryon solution. The effective four-dimensional pion action is analyzed and is shown to reproduce the chiral Lagrangian, including the Skyrme and Wess-Zumino-Witten terms.
↳ hep-thhep-phmath-phmath.MP0 citations
40
Realizing Error Suppression in Partially Fault-Tolerant Quantum Simulations with IBM Quantum Computers
Henry Froland🇺🇸 · Dorota M. Grabowska🇺🇸 · Sebastian Grieninger🇺🇸 · Jeremy Hartse🇺🇸 · Anne L. Lashbrook · Zhiyao Li🇺🇸 · Ziyuan Li · Sarah J. M. Powell · Martin J. Savage🇺🇸 · Xiaojun Yao🇺🇸 · Nikita A. Zemlevskiy🇺🇸
Quantum error-detecting codes offer a near-term path for improving the performance of quantum simulations on noisy hardware. Using IBM's superconducting quantum computer ibm_boston, we show that partially fault-tolerant encoded quantum simulations of the Ising model in 1+1D and 2+1D outperform their unencoded counterparts in estimating local observables. To represent 42 logical qubits on the heavy-hex quantum processor, 21 blocks of the [[4, 2, 2]] Iceberg code and up to 136 physical qubits are used. By pairing fault-tolerant syndrome extraction with non-fault-tolerant logical operations, this scheme preserves many of the benefits of error detection while avoiding the overhead typically required for a fully fault-tolerant logical gate set. The encoding's square logical connectivity, together with the freedom to place logical qubits within each block, enables simulations of a 2D spatial lattice with lower circuit depth than the unencoded implementation requires. We introduce Observable-Ranked Postselection, a selective-filtering technique based on syndrome correlations that recovers reliable results without the prohibitive shot loss of full syndrome postselection. Under the cumulative effect of device errors, this encoding improves local-observable accuracy over the unencoded baseline by 2-6% at intermediate times in 1+1D simulations, growing with circuit depth to over 200% in 2+1D at the latest times studied.
↳ quant-phhep-lathep-phnucl-th2 citations
41
CosmoLattice 2.0
Jorge Baeza-Ballesteros🇩🇪 · Daniel G. Figueroa🇪🇸 · Adrien Florio🇩🇪 · Nicolás Loayza🇪🇸 · Franz R. Sattler🇩🇪 · Francisco Torrentí🇪🇸 · Ander Urio🇪🇸
This paper introduces $C osmo L attice$ $v2.0$ , a major upgrade that substantially broadens the physical scope and computational capabilities of the code. It introduces lattice implementations of scalar fields non-minimally coupled to gravity through $ϕ^{2} R$ , as well as axion-like fields coupled to Abelian gauge sectors as $ϕ F_{μν} F^{μν}$ . It also provides new procedures for generating specialized initial conditions, including scaling networks of cosmic defects ( $e.g.$ strings and domain walls), and fields with arbitrary power spectra. The release also incorporates low-storage Runge-Kutta integrators for non-symplectic systems (suitable $e.g.$ for non-minimal scalar kinetic terms as $G_{ab} \partial_{μ} ϕ^{a} \partial^{μ} ϕ^{b}$ ), scalar-field simulations on reduced $(1 + 1)$ - and $(2 + 1)$ -dimensional lattices, new optimized gravitational-wave evolution, more flexible field and energy-density outputs, and GPU support that can accelerate simulations by a factor $O (10)$ relative to CPU execution. Extensive documentation on the use of the code is provided on https://www.cosmolattice.com
↳ astro-ph.COhep-ph1 citation
42
Fixing IR tail of gravitational waves from domain walls
Ivan Dankovsky🇷🇺 · Dmitry Gorbunov🇷🇺
Numerical simulations of gravitational waves (GW) production during violent evolution of matter inhomogeneities in the early Universe yield highly wiggle infrared parts of the spectra. Obtained directly from the two-point correlation function, these wiggles are nonphysical, corresponding to the parasitic, double frequency terms in naively averaged squared oscillation amplitudes of GW, and hence must be washed out. The deep infrared behavior can be predicted on general grounds, e.g. fixed by causality considerations. However, what matters for real observations, e.g. like that of NANOGrav, and what can be only inferred from numerical simulations, is the infrared slope near the maximum of the spectrum. It reflects the dynamics responsible for the GW production in its heyday, and hence must be accurately predicted. We illustrate the problem with numerical simulations of the Domain Wall network performed with the help of code CosmoLattice. We suggest a numerical procedure to smooth out these parasitic wiggles, which allows us to recover the true spectrum. Being quite generic, it may be applied to numerical simulations of other hypothetical sources of GW possibly operating in the early Universe. The procedure requires to extend the simulation by a few Hubble times after termination of the GW production. We checked with numerical simulations, that the technically natural long-time extension of simulations, which becomes available via artificial scaling of different parts in the scalar sector equations provided by PRS prescription, gives wrong GW spectra even if the source terms are properly rescaled.
↳ gr-qcastro-ph.COhep-ph1 citation
43
The quantum electrodynamics for dyons
D.O.R. Azevedo🇺🇾 · O.M. Del Cima🇧🇷 · T.S. Dias🇧🇷 · E.D. Pereira🇧🇷
The quantum electrodynamics for massive fermions carrying electric and magnetic charges, the dyons, is proposed based on the 1960's seminal works by Cabibbo, Ferrari, and Salam, with the gauge group being $U (1) \times U (1)$ , which is associated to a vector field (photon) and a pseudo-vector field (metaphoton), wherein the Dirac quantization is set aside. At the tree level the spectrum consistency of the model is analyzed, and all continuous and discrete symmetries are established. The quantum analysis is performed by using the Becchi-Rouet-Stora (BRS) algebraic renormalization method, which is independent on any regularization scheme. Moreover, thanks to the presence of massless gauge fields, the Lowenstein-Zimmermann (LZ) subtraction scheme is required within the framework of the Bogoliubov-Parasiuk-Hepp-Zimmermann-Lowenstein (BPHZL) renormalization procedure. Finally, it is verified that the proposed model, the dyon quantum electrodynamics (dQED), is free from any anomaly and is multiplicative renormalizable at all orders in perturbation theory, proving, therefore, its quantum consistency.
↳ hep-thgr-qchep-exhep-ph+20 citations
44
Normalizing Flows to Reconstruct Pseudo-PDFs
Yamil Cahuana Medrano🇺🇸 · Kostas Orginos🇺🇸
We investigate a normalizing-flow approach for reconstructing parton distribution functions (PDFs) from synthetic matrix-element data. Our framework combines Gaussian Process priors with invertible neural networks to learn a posterior distribution over PDFs consistent with limited Ioffe-time data. We demonstrate that the architecture preserves physical constraints and extrapolation properties.
↳ hep-latcs.LGhep-ph1 citation
45
Gravitational Waves from Superconducting Cosmic Strings
Jinyoung Jhun · Takashi Hiramatsu🇯🇵
We study the evolution of superconducting cosmic-string networks in a $U (1)_{local} \times U (1)_{global}$ field-theoretic model using three-dimensional lattice field simulations in an expanding universe. The scalar field charged under $U (1)_{local}$ forms cosmic strings, while the scalar field associated with $U (1)_{global}$ acts as a current carrier and condenses in their vicinity. We investigate the evolution of the string network for several values of the coupling constant between the string-forming and current-carrier fields and estimate the gravitational-wave power spectrum sourced by the resulting superconducting cosmic-string network. We find that the spectral shape depends on the coupling constant: as the interaction strength increases, the spectrum is suppressed on small scales. This feature may be probed by future high-frequency gravitational-wave observations.
↳ astro-ph.COgr-qchep-phhep-th0 citations
46
Neutrino-electron scattering kernels in isotropic media
Jens Chluba🇬🇧 · Bryce Cyr🇺🇸 · Michiru Uwabo-Niibo🇰🇷 · Masahide Yamaguchi🇰🇷
In the early universe, neutrinos undergo many interactions with the particles in the plasma. Key processes are the scattering of neutrinos by free electrons and positrons. In this paper, we derive general expressions for the electron neutrino-electron scattering kernel in isotropic media, analytically simplifying the 5D collision integral to two dimensions. We follow a procedure that is similar to the derivation of the Compton scattering kernel to reduce the angular integrals, yielding a compact analytic expression in terms of elementary functions that can be easily evaluated. We illustrate the properties of this kernel and also compute its first moments analytically, providing insights into the energetics of the redistribution process. For comparison, we consider the photon-electron scattering kernel, highlighting differences and similarities. We then explain how the obtained expressions can also be applied to the $ν_{μ / τ}$ -electron and neutrino-positron scattering processes. The results presented here may be useful in the context of Big Bang Nucleosynthesis and were added as an extension to the Compton scattering library CSpack for more general applications.
↳ astro-ph.COhep-phhep-th0 citations
47
String theory mathematics and matrix data analysis
Sanjaye Ramgoolam🇬🇧
Inspired by matrix techniques in quantum field theory and string theory, we review Permutation Invariant Gaussian Matrix Models (PIGMM), which replace the continuous symmetries of traditional Random Matrix Theory, for $N \times N$ matrices, with finite permutation symmetry, $S_{N}$ . This symmetry-driven approach reduces highly multivariate $N^{2}$ -variable matrix data analysis problems to a rich but tractable space of parameters. The representation theory of $S_{N}$ brings a highly correlated quadratic matrix action to a near-diagonal form with $13$ parameters. The invariant observables are parameterised by graphs and their expectation values are computed with Wick contractions implemented algorithmically. We review the successful application of PIGMM for data reduction and anomaly detection in computational linguistics, statistical finance and neural network weights. We conclude with a brief discussion of potential future applications to matrix data analysis tasks that exploit hadronization algorithms and the modular structure of collider-physics data.
↳ hep-thhep-ph0 citations
48
The Development of Detectors of High Energy Neutrinos and Cosmic Rays between 1980 and 2000
A A Watson🇩🇪
The construction of the DUMAND, Lake Baikal and IceCube detectors of high-energy neutrinos are discussed, with some emphasis on the difficulties encountered. The decade from 1990 marked the period in which the Auger Observatory was conceived and the Collaboration evolved. Again, the difficulties that were overcome to create the Observatory are described. For both IceCube and the Auger Observatory, claims made in the 1980s for the observation of PeV gamma-rays from Cygnus X-3, played a not-insignificant role in their advance.
↳ physics.hist-phhep-ph0 citations
49
Path-length dependence of parton energy loss across collision systems: a Bayesian analysis of charged-particle RAA, consistent with a universal exponent from O+O to Pb+Pb
Fouad A. Majeed · Hussein Ali Hussein Al Naffakh · Sarah M. Obaid · Muntaha Abdullah Reishaan
How parton energy loss in the quark-gluon plasma (QGP) scales with the in-medium path length $L$ encodes the mechanism: collisional ( $Δ E \propto L$ ), radiative ( $Δ E \propto L^{2}$ ), or strong-coupling ( $Δ E \propto L^{3}$ ). Exploiting the new CERN LHC light-ion data, we extract this scaling from the system size itself, jointly analysing CMS charged-particle nuclear modification factors $R_{AA}$ in four systems - O+O, Ne+Ne, Xe+Xe and Pb+Pb - spanning mass number $A = 16$ to $208$ . A Bayesian analysis with a data-driven spectral baseline and a Monte-Carlo Glauber geometry yields an effective system-size exponent $n = 1.78 \pm 0.15 (stat) \pm 0.05 (syst)$ . Nested-sampling model selection decisively favours an effective exponent near the radiative value ( $n = 2$ ) over the collisional ( $n = 1$ ) and strong-coupling ( $n = 3$ ) values, a conclusion stable across all 160 analysis variants. Because fluctuations can only lower the effective exponent below its microscopic counterpart, the measurement bounds the latter from below at fixed geometry, excluding purely collisional energy loss. The medium density and the path length are degenerate across system size, so we quote the effective exponent as our primary result. A Bayes-factor test finds no change of regime between small and large systems, consistent with a universal exponent; the same framework gives decisive evidence for non-zero energy loss in O+O alone, quantifying the onset of suppression in the smallest system. The energy-loss magnitude corresponds to $q^/ T^{3} \approx 2$ -- $5$ , consistent with the JETSCAPE determination.
↳ nucl-thhep-ph0 citations
50
Pair luminosity and cooling of newborn strange star: Color-flavor-locked and two-flavor color superconducting quarks
Mikalai Prakapenia🇧🇾 · Cheng-Jun Xia🇨🇳 · Gregory Vereshchagin🇧🇾
Following the previous wor k[1] here we consider early thermal evolution of hot strange stars made of color superconducting quarks in two different pairing states: two-flavor color superconductor (2SC) and color-flavor-locked (CFL) phases, taking into account cooling by neutrinos and electron-positron pair creation due to the Schwinger process. We show that Schwinger luminosity in the electrosphere is a universal function of temperature, independent of quark matter phase for quark chemical potential $μ_{q} > 280$ MeV. The surface of a strange star in all the cases cools faster than its interior. This leads to a fast decrease of pair luminosity with time, so that it does not exceed $1 0^{46}$ erg/s at 1 second after strange star formation. Neutrino luminosity dominates over pair luminosity in all the cases except for the CFL phase with a large gap parameter $Δ > 60$ MeV, where there is a strong suppression of neutrino emission. The total energy emitted in electron-positron pairs is always smaller than the energy emitted in neutrinos, but they become comparable for the large gap parameter.
↳ astro-ph.HEhep-phPRD(2026)·0 citations
51
$Λ$ XCDM: a running vacuum strategy for crossing the phantom divide
Joan Solà Peracaula🇪🇸 · Adrià Gómez-Valent🇪🇸 · Alex González-Fuentes🇪🇸
Composite dynamical dark energy (DDE) has recently been explored as an efficient way to help cure cosmological tensions through the so-called $w$ XCDM model (Gomez-Valent & Solà Peracaula 2024; 2025), a toy-model version of the $Λ$ XCDM model (Grande et al., 2006). The latter is a composite running vacuum model (RVM) that involves a DE component $X$ (`cosmon') of generic nature. We compute the effective equation of state of $Λ$ XCDM and use state-of-the-art techniques to fit this model to two standard sets of cosmological data, one involving SNIa from Pantheon $+$ and the other SNIa from DES-Dovekie, in addition to BAO data from DESI DR2 and the CMB data from Planck PR4. We do not use large scale structure formation data for this analysis nor the SH0ES calibration of $H_{0}$ . We find that $Λ$ XCDM naturally performs the crossing of the phantom divide as observed by DESI near $z ≃ 0.4$ using the $w_{0} w_{a}$ CDM parameterization, a feature well favored by existing model-agnostic analyzes of the same data (González-Fuentes & Gómez-Valent:2025; 2026). It turns out that the cosmon $X$ behaves as `phantom matter' (PM) near the present, which in contrast to usual phantom DE satisfies the strong energy condition (as ordinary matter) and furnishes positive pressure ( $P_{X} > - ρ_{X} > 0$ ) at the expense of negative energy density ( $ρ_{X} < 0$ ). $Λ$ XCDM provides a better fit than $w_{0} w_{a}$ CDM and, as a bonus, alleviates the cosmic coincidence problem. Given that PM appears in stringy versions of the RVM (Mavromatos & Solà Peracaula 2021 a,b) , the $Λ$ XCDM appears to be a composite DDE model with a good chance of explaining the crossing of the phantom divide from first principles, therefore providing theoretical support to the DESI observations inferred from generic parameterizations of the DE.
↳ astro-ph.COgr-qchep-ph1 citation

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first authorsco-authorsvia INSPIRE