HEP Phenomenology·hep-ph

Fri·Oct 24, 2025Friday·October 24, 2025

16 papers—11 primary·5 cross-listed·reconstructed*

01*
A simple model for PDFs and nPDFs
A.V. Kotikov🇷🇺 · A.V. Lipatov🇷🇺
We present the main results of our recent papers, where we derived an analytical solution of the QCD evolution equations for parton distribution functions. The valence and non-singlet quark components satisfy the Gross-Llewellyn-Smith and Gottfried sum rules, respectively, while momentum conservation is maintained for the singlet quark and gluon densities. Several phenomenological parameters were extracted from a combined fit to precision data on the proton structure function $F_{2} (x, Q^{2})$ collected by the BCDMS, H1, and ZEUS Collaborations, comprising a total of 933 points from 5 datasets. We proposed a model for nuclear medium modifications of parton densities. The approach is based on a global analysis of available deep inelastic scattering data for different nuclear targets within the rescaling model, incorporating Fermi motion effects. By fitting the rescaling parameters to experimental data on the ratio $F_{2}^{A} (x, Q^{2}) / F_{2}^{D} (x, Q^{2})$ for several nuclear targets $A$ , we obtained predictions for nuclear parton distribution functions.
hep-ph0 citations
02*
Holographic light-front QCD
Hans Guente Dosch🇩🇪 · Guy F. de Teramond🇨🇷 · Stanley J. Brodsky🇺🇸
This brief review presents the key components of light-front holographic quantum chromodynamics (HLFQCD). Particular attention is given to the introduction of the QCD color confinement scale within the context of a graded superconformal algebra. A concise overview of applications is provided, including spectroscopy, form factors, parton distributions of hadrons, and the relationship between entanglement entropy and high-energy scattering. While many other recent applications of HLFQCD exist in the literature, they are not included in this short overview of our latest work.
hep-phJ.Subatomic Part.Cosmol.(2026)·4 citations
03*
Eigen-microstate Signatures of Criticality in Relativistic Heavy-Ion Collisions
Ranran Guo🇨🇳 · Jin Wu🇨🇳 · Mingmei Xu🇨🇳 · Xiaosong Chen🇨🇳 · Zhiming Li🇨🇳 · Zhengning Yin🇨🇳 · Yuanfang Wu🇨🇳
We develop the eigen-microstate framework as a new approach to identify criticality in relativistic heavy-ion collisions. We construct the original microstate, defined as the final-state particle fluctuations of a single event. By examining ensembles of such original microstates with and without critical signals, we demonstrate that the corresponding eigen-microstate can extract and reveal the dominant critical mode, with the largest eigenvalue serving as a robust order parameter. This framework avoids equilibrium assumptions and is insensitive to non-critical background, and the approach is directly applicable to RHIC Beam Energy Scan data, offering a powerful new tool in the search for the QCD critical point.
hep-phPLB(2026)·3 citations
04*
Symbolic Regression and Differentiable Fits in Beyond the Standard Model Physics
Shehu AbdusSalam🇮🇷 · Steven Abel🇬🇧 · Deaglan Bartlett🇫🇷 · Miguel Crispim Romão🇬🇧
We demonstrate the efficacy of symbolic regression (SR) to probe models of particle physics Beyond the Standard Model (BSM), by considering the so-called Constrained Minimal Supersymmetric Standard Model (CMSSM). Like many incarnations of BSM physics this model has a number (four) of arbitrary parameters, which determine the experimental signals, and cosmological observables such as the dark matter relic density. We show that analysis of the phenomenology can be greatly accelerated by using symbolic expressions derived for the observables in terms of the input parameters. Here we focus on the Higgs mass, the cold dark matter relic density, and the contribution to the anomalous magnetic moment of the muon. We find that SR can produce remarkably accurate expressions. Using them we make global fits to derive the posterior probability densities of the CMSSM input parameters which are in good agreement with those performed using conventional methods. Moreover, we demonstrate a major advantage of SR which is the ability to make fits using differentiable methods rather than sampling methods. We also compare the method with neural network (NN) regression. SR produces more globally robust results, while NNs require data that is focussed on the promising regions in order to be equally performant.
hep-phastro-ph.COcs.AIcs.LG+1Phil.Trans.Roy.Soc.Lond.A(2026)·4 citations
05*
GUT-Scale Smooth Hybrid Inflation with a Stabilized Modulus in Light of ACT and SPT Data
Waqas Ahmed🇨🇳 · Constantinos Pallis🇬🇷 · Mansoor Ur Rehman🇸🇦
We analyze a generalized framework of smooth F-term hybrid inflation (smFHI) consistent with gauge coupling unification within the Minimal Supersymmetric Standard Model (MSSM). The embedding of the model in two specific Supergravity settings addresses at the same time the $η$ problem and the compatibility with the recent ACT or SPT data. The one relies on the choice of a shift-symmetric Kähler potential for the inflaton which revitalizes the SUSY predictions of smFHI, whereas the other employs a Kähler potential associated with an hyperbolic Kähler manifold. An essential role in both our constructions is played by a decoupled superheavy field without superpotential and Kaehler potential inspired by string- and D-brane--based models. Our proposal can be realized for a variety of representations for the Higgs fields involved in smFHI and assures monotonic inflationary potential.
hep-phastro-ph.COhep-thJCAP(2026)·10 citations
06*
NNLO QCD predictions for jet observables in ZH production at electron-positron colliders
Simone Caletti🇨🇭 · Aude Gehrmann-De Ridder🇨🇭 · Matteo Marcoli🇬🇧
We present precise predictions for a variety of jet observables in $Z H$ production at electron-positron colliders, with the $Z$ boson decaying leptonically and the Higgs boson decaying into two hadronic jets, up to NNLO in perturbative QCD. We consider a Higgs boson decaying into bottom (charm) quark pairs via Yukawa interaction and into gluons via an effective vertex in the limit of infinite top quark mass. We present results for the two decay modes separately, highlighting relevant differences in the differential distributions, and for the sum of all decay channels, including a comparison between different choices of the Durham (or $k_{T}$ ) jet resolution parameter.
hep-phJHEP(2026)·2 citations
07*
On the Resonance Coupling and Width in Quantum Field Theory
Dmitri Melikhov🇷🇺
In quantum field theory, characteristics of resonances are related to self-energy diagrams, which are ultra-violet divergent and require renormalization. We demonstrate the proper way to define the resonance coupling $g_{M}$ such that the resonance properties calculated in quantum field theory are finite and scheme-independent quantities.
hep-ph0 citations
08*
QCD corrections to the electroweak sphaleron rate
Dietrich Bödeker🇩🇪 · Philipp Klose🇳🇱
The electroweak sphaleron rate in the high temperature phase of the Standard Model is inversely proportional to the weak-isospin conductivity. So far, only electroweak interactions were included in its computation. Here we take into account quark scattering through strong interactions at leading-log order. These reduce the quark contribution to the conductivity by up to 15 %, and the total conductivity by up to 6 %.
hep-phastro-ph.COJHEP(2026)·3 citations
09*
Proposal to use laser-accelerated electrons to probe the axion-electron coupling
Georgios Vacalis🇬🇧 · Atsushi Higuchi🇬🇧 · Robert Bingham🇬🇧 · Gianluca Gregori🇬🇧
The axion is a hypothetical particle associated with a possible solution to the strong CP problem and is a leading candidate for dark matter. In this paper we investigate the emission of axions by accelerated electrons. We find the emission probability and energy within the WKB approximation for an electron accelerated by an electromagnetic field. As an application, we estimate the number of axions produced by electrons accelerated using two counter-propagating high-intensity lasers and discuss how they would be converted to photons to be detected. We find that, under realistic experimental conditions, competitive model-independent bounds on the coupling between the axion and the electron could be achieved in such an experiment.
hep-phPRL(2025)·5 citations
10*
An Axial-Vector Leptophilic Fifth Force Sourced by Solar Neutrinos
Rundong Fang🇨🇳 · Ji-Heng Guo🇨🇳 · Jia Liu🇨🇳 · Xiao-Ping Wang🇨🇳 · YanLi Zhao🇨🇳
We investigate long-range, purely leptophilic axial-vector interactions mediated by a light gauge boson $A^{'}$ that couples to charged leptons and, by weak symmetry, to left-handed neutrinos. We analyze two realizations, a minimal effective model with muon-only couplings and an anomaly-free axial $U (1)^{'}$ with inter-generation cancellations. In both cases, the solar neutrino flux acts as an extended current that sources a macroscopic $A^{'}$ field at Earth, with spatial components aligned along the Sun-Earth direction. This field produces a distinctive signature in storage-ring measurements of the muon anomalous magnetic moment, $(g - 2)_{μ}$ , namely a diurnal, sign-changing contribution that is positive during daytime and negative at night, superimposed on a time-independent positive offset. We obtain bounds $g^{'} ≲ O (1 0^{- 19})$ in both model frameworks for a light, effectively massless mediator. For completeness, we map the solar-neutrino-sourced potential to electron spin-sensor experiments and find $g^{'} ≲ O (1 0^{- 22})$ in the electron channel.
hep-phhep-exPRD(2026)·2 citations
11*
Shear viscosity of a binary mixture for a relativistic fluid at high temperature
Gabriele Parisi🇮🇹 · Vincenzo Nugara🇮🇹 · Salvatore Plumari🇮🇹 · Vincenzo Greco🇮🇹
The determination of the shear viscosity is a central topic in various areas of modern physics. In particular, it is often necessary to evaluate the shear viscosity $η$ of fluids made up of more than one species, all interacting with different cross sections. Since it may be difficult to extract information on the interaction among different species, various combinations of the viscosities of the individual components are often used. We work in the Chapman-Enskog framework and investigate on binary mixtures, by comparing such single component combinations with a full 2-component formalism: we find that, in most cases, the full viscosity is well approximated by a weighted linear average of the single component viscosities, although this result is far from being general. Moreover, we validate our 2-component Chapman-Enskog results for $η$ by comparing them with an independent numerical simulation of the Boltzmann equation, which estimates the shear viscosity via a Green-Kubo formula, in the case of a quasi-particle system that reproduces lattice QCD thermodynamics. We see that the temperature dependence of $η / s$ of such system of quarks and gluons is not well described by combinations of the individual components, highlighting the importance of inter-species scattering.
hep-phhep-thPRD(2026)·7 citations
12*
Dephasing in binary black hole mergers surrounded by scalar wave dark matter clouds
Cheng-Hsin Cheng🇺🇸 · Giuseppe Ficarra🇮🇹 · Helvi Witek🇺🇸
Scalar fields of masses between $1 0^{- 21} eV / c^{2}$ and $1 0^{- 11} eV / c^{2}$ can exhibit enhanced gravitational interactions with black holes, and form scalar clouds around them. Such a cloud modifies the dynamics of a coalescing black-hole binary, and the resulting gravitational waves may provide a new channel to detect light scalar fields, such as axion-like particles or wave-like dark matter candidates. In this work we simulate a series of black-hole mergers with mass ratios $q = 1$ and $q = 1/2$ , immersed in an scalar field overdensity with masses in the range $M μ_{S} \in [0, 1.0]$ . To do so, we implemented a constraint-satisfying initial data solver based on the puncture method, we improved the accuracy of our open-source software Canuda to eighth order finite differences, and we reduced the initial orbital eccentricity. We investigate the impact of the scalar mass on the gravitational and scalar radiation. We find that binaries can undergo a delayed or an accelerated merger with respect to the vacuum. Our study highlights the challenge and importance of accurately modeling black-hole binaries in dark matter environments.
↳ gr-qcastro-ph.HEhep-phPRD(2026)·12 citations
13*
Two-loop QCD Amplitudes from the Chiral Algebra Bootstrap
Anthony Morales🇺🇸
We show that the chiral algebra bootstrap, which computes form factors of twistorial theories, can help determine two-loop amplitudes in massless QCD. We give an $n$ -gluon result for a previously unknown partial amplitude of the two-loop all-plus-helicity QCD amplitude by utilizing supersymmetry Ward identities and known chiral algebra bootstrap results. We then show that the full-color two-loop $n$ -gluon amplitude of QCD with $n_{f}$ quark flavors can be obtained from certain two-loop form factors of twistorial theories and one-loop and tree-level amplitudes. Chiral algebra bootstrap results exist for these form factors when all gluons have positive helicities. Hence, the bootstrap simplifies the computation of these two-loop amplitudes by one loop level.
↳ hep-thhep-phPRD(2026)·6 citations
14*
Gauss-Bonnet entropy and thermal dynamics of RN-AdS black holes
M. Z. Bhatti🇵🇰 · Kazuharu Bamba🇯🇵 · I. Siddique🇵🇰 · Bander Almutairi🇸🇦 · Z. Yousaf🇵🇰
We explore the thermodynamics of a novel solution for the Reissner-Nordström-Anti-de Sitter (AdS) black hole, uniquely incorporating the Gauss-Bonnet term. Unlike previous studies that primarily focused on standard General Relativity or other modifications, this inclusion allows for a modified entropy formulation, facilitating the computation of key thermodynamic quantities such as Gibbs free energy, the first law of thermodynamics, the equation of state, and Hawking temperature. We identify critical points and graphically represent the relationship between temperature and Gibbs free energy as a function of the horizon radius. Ultimately, we assess the thermal stability of the Reissner-Nordström-AdS black hole within the framework of Gauss-Bonnet gravity, emphasizing the influence of the Gauss-Bonnet term unlike previous studies that primarily focused on standard General Relativity or other modifications. As a result, it is found that the Gauss-Bonnet coupling significantly alters the thermodynamic behavior and stability structure of the black hole, revealing richer phase transition phenomena.
↳ gr-qchep-phhep-thGen.Rel.Grav.(2025)·0 citations
15*
Bootstrapping Six-Gluon QCD Amplitudes
Sérgio Carrôlo🇩🇪 · Dmitry Chicherin🇫🇷 · Johannes Henn🇩🇪 · Qinglin Yang🇩🇪 · Yang Zhang🇨🇳
We present a symbol-level bootstrap construction of the planar, two-loop six-gluon scattering amplitude for the --++++ helicity configuration in QCD, focusing on the maximal weight pieces-the "most complicated terms" in the sense of Lipatov et al. Building on recent advances in the understanding of the relevant function space, we incorporate as a crucial new ingredient the complete set of leading singularities, obtained from an explicit analysis of on-shell diagrams. The resulting expressions are manifestly conformally invariant and clarify the structure of previous five-particle results. Combining this with the symbol bootstrap, we show that constraints from physical limits are sufficient to uniquely determine the answer. We thus obtain the first concrete characterization of two-loop six-gluon amplitudes at the symbol level and at highest weight. Remarkably, we find that the effective function space involves only 137 symbol letters, significantly fewer than the full set of 167 possible letters, suggesting a yet-unexplained underlying structure akin to that seen in maximally supersymmetric Yang-Mills theory. From the novel amplitude results we extract previously unknown symbol-level results describing two-loop triple collinear and double soft limits.
↳ hep-thhep-phPRL(2026)·8 citations
16*
SENSEI: A Search for Diurnal Modulation in sub-GeV Dark Matter Scattering
Itay M. Bloch🇺🇸 · Ana M. Botti🇺🇸 · Mariano Cababie🇺🇸 · Gustavo Cancelo🇺🇸 · Brenda A. Cervantes-Vergara🇲🇽 · Miguel Daal🇮🇱 · Ansh Desai🇺🇸 · Alex Drlica-Wagner🇺🇸 · Rouven Essig🇺🇸 · Juan Estrada🇺🇸 · Erez Etzion🇮🇱 · Guillermo Fernandez Moroni🇺🇸 and 19 other authors
Dark matter particles with sufficiently large interactions with ordinary matter can scatter in the Earth's atmosphere and crust before reaching an underground detector. This Earth-shielding effect can induce a directional dependence in the dark matter flux, leading to a sidereal daily modulation in the signal rate. We perform a search for such a modulation using data from the SENSEI experiment, targeting MeV-scale dark matter. We achieve an order-of-magnitude improvement in sensitivity over previous direct-detection bounds for dark-matter masses below 1 MeV, assuming the Standard Halo Model with a Maxwell--Boltzmann velocity distribution, and constrain the amplitude of a general daily modulation signal to be below 6.8 electrons per gram per day.
↳ hep-exastro-ph.COhep-phPRL(2026)·9 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.