HEP Phenomenology·hep-ph

Fri·Jul 17, 2026Friday·July 17, 2026

33 papers—24 primary·9 cross-listed

01
Candia-v2: Logarithmic expansions for DGLAP evolution in $x$ -space
Casey Hampson🇺🇸 · Marco Guzzi🇺🇸
We present Candia-v2, an open-source software package that generalizes the $x$ -space Candia algorithm to next-to-next-to-next-to-leading order (N $^{3}$ LO) accuracy in Quantum Chromodynamics (QCD). The code solves the DGLAP evolution equations for unpolarized nucleon parton densities using a highly efficient logarithmic expansion technique that can be systematically extended to all orders in QCD. Candia-v2 supersedes the previous original C implementation of the algorithm with significantly increased efficiency and improved API. The software is publicly available on GitHub under the GPLv3 license.
hep-phhep-ex0 citations
02
New approach to the estimation of the lowest boundary of an axion mass
Sevinj O. Huseynova🇦🇿 · Vali A. Huseynov🇦🇿 · Nigar E. Musazade🇦🇿 · Sevinj Y. Rzayeva🇦🇿
In this work, we have performed the theoretical estimation of the lowest boundary of an axion mass. We have analyzed the energy spectrum of the electron in a constant homogeneous magnetic field, taking into account its anomalous magnetic moment. We have applied the obtained results on the energy spectrum of the electron in a constant homogeneous magnetic field with allowance for its anomalous magnetic moment to the hydrogen atom electron, which is located in addition to the Coulomb field of the proton, as well as in the magnetic field produced by the magnetic moment of the proton. We have applied the idea of the restriction for the lowest boundary of the axion mass to the triplet-singlet transition between two adjacent levels obtained as a result of the hyperfine structure splitting of the s-levels in the hydrogen atom. We have concluded that the mass of an axion ought to be more than 5.885 microelectron-Volt. We have determined that the minimum value of the magnetic field strength at which the axion emission by the electron in a magnetic field starts to be realized is determined by the axion mass. This result enables us to estimate the expected value of the lowest boundary for the axion mass (of the order of 10 microelectron-Volt), assuming that some part of the solar axions is emitted by the electrons located in sunspots.
hep-phhep-th0 citations
03
Dark matter in composite Higgs models with a scotogenic EFT
Yu Chen🇩🇪 · Werner Porod🇩🇪
We discuss a class of Composite Higgs models with a fermionic UV completion that can explain the dark matter relic density. The resulting low-energy theory resembles so-called scotogenic models. A residual $Z_{2}$ symmetry implies that one of the pseudo-Nambu-Goldstone bosons is stable and therefore is a viable dark matter candidate. As a concrete example, we take a model based on the $SU (6) / Sp (6)$ coset, which in principle contains four dark matter candidates. However, only three of them can produce a relic density consistent with observations. We perform a MCMC study focusing on dark matter observables to explore the available parameter space of the effective theory. In particular, we find that spin-1 resonances play an important role in a substantial part of the parameter space. Finally, we comment on possible LHC signatures of this model class.
hep-ph0 citations
04
Searching for the $N$ -naturalness tower of neutrinos
Sofia Lonardi🇩🇪 · Manuel Ettengruber🇫🇷 · Philipp Eller🇩🇪
We present the first experimental search for the $N$ -naturalness tower of neutrinos using a global analysis of publicly available neutrino data. As a potential solution to the hierarchy problem, the $N$ -naturalness model employs a varying Higgs mass parameter among $N$ dark sectors and encodes the required fine-tuning of the placement of the sectors in a parameter $r$ . We report exclusion limits on the parameter space ( $r$ , $N$ ), for normal and inverted ordering and in case the neutrino is Majorana or Dirac. In the case of a Majorana neutrino, we can rule out $N \leq 1 0^{4}$ sectors with $r \geq 0.1$ . This is particularly exciting as it shows that a gauge and gravitational unification around $M_{G U T}$ , which is a benchmark scenario of the $N$ -naturalness framework with $N = 1 0^{4}$ without fine-tuning, is ruled out by neutrino experiments.
hep-phhep-ex0 citations
05
Constraining the Coexistence of Primordial Black Holes and Particle Dark Matter with Neutrino Observations
Prolay Chanda🇮🇳 · Sagnik Mukherjee🇺🇸 · James Unwin🇺🇸
Primordial black holes (PBH) with a uniform mass scale could contribute up to 1\% of the gravitationally inferred dark matter relic abundance and remain consistent with observational limits over a large range of masses. In this case, the vast majority of the dark matter relic abundance is comprised of dark matter particles, such as WIMPs or FIMPs. Particle dark matter gravitationally captured around primordial black holes can form dense minispikes in which the annihilation rate is strongly enhanced. In this work, we investigate the constraints on the coexistence of PBHs and particle dark matter from high-energy neutrino observations. Relative to earlier analyses, we refine the treatment of the dark matter halo profile and its redshift evolution. We consider models of freeze-out and freeze-in dark matter, as well as Boltzmann-suppressed freeze-in. We present idealized IceCube event-based sensitivities together with conservative limits obtained by requiring that the predicted extragalactic neutrino intensity not exceed the upper envelope of the measured diffuse flux. We explore the constraints in terms of an idealized model with 100\% branching to neutrinos, we also discuss these results within the context fo a motivated gauged U(1) $_{L_{μ} - L_{τ}}$ mediator model, emphasizing that a consistent particle-physics completion generally predicts correlated charged-lepton and neutrino final states.
hep-phastro-ph.HE0 citations
06
Collinear Factorization Violation and Reggeization
Damiano Barcaro🇩🇪 · Anjie Gao🇺🇸 · Jonathan R. Gaunt🇬🇧 · Aditya Pathak🇩🇪
We derive an all-order soft-collinear subgraph factorization in the space-like collinear limits of amplitudes for single gluon pinched in the Glauber region. We show that these contributions exhibit Reggeization, combining aspects of both forward and hard scattering. By deforming away from the Glauber region wherever possible we demonstrate a dramatic simplification of the effective theory subgraphs and thereby drastically reducing the complexity in computing collinear factorization breaking terms in multi-point amplitudes. Our work is aided with development of new software tools initiating a systematic study of processes involving Glauber exchanges at a multi-loop level.
hep-ph3 citations
07
Production Effects and Final-state Interactions in $π_{1} \to 3 π$
D. Winney🇲🇽 · S. Gonzàlez-Solís🇪🇸 · M. Mikhasenko🇩🇪 · Ł. Bibrzycki🇵🇱 · C. Fernández-Ramírez🇪🇸 · V. Mathieu🇪🇸 · G. Montaña🇪🇸 · A. Pilloni🇮🇹 · L. Qiu🇺🇸 · A. Rodas🇺🇸 · A. P. Szczepaniak🇺🇸
We investigate the $π_{1} (1600)$ signal channel of $3 π$ in the $J^{P C} = 1^{-+} [π π]_{1^{--}} π P$ -wave. This channel has recently been analyzed by the COMPASS collaboration using the ``freed-isobar" technique which provides direct experimental access to the lineshape modifications of the $P$ -wave $π π$ sub-channel arising from both final state interactions and production processes such as the Deck mechanism. We motivate a unified formalism combining production effects and final state interactions using the Khuri-Treiman formalism, which is consistent with low-energy unitarity, analyticity, and crossing symmetry, seeded by an initial production amplitude. We demonstrate that the precise lineshape of the $π π$ mass spectrum can be used to determine the relative strength and complex phase of different production mechanisms contributing to the $3 π$ final state. We conduct a global fit of the $π_{1}$ freed-isobar data set, yielding a multi-dimensional parameterization of the $π_{1} \to 3 π$ decay amplitude at COMPASS as a function of both decay and production variables. We identify the contributions from short-range production and the Deck mechanism and extract the total $3 π$ invariant mass dependence which will be important for a future extraction of the $π_{1}$ pole position in the $ρ π$ channel.
hep-phhep-exnucl-th0 citations
08
Exotic states with charm and/or strangeness
A. Martínez Torres🇧🇷 · Breno Agatão🇧🇷 · Pedro Brandão🇧🇷 · K. P. Khemchandani🇧🇷 · Luciano M. Abreu🇧🇷 · E. Oset🇪🇸
In this talk, I will discuss the properties of several exotic states with charm and/or strangeness. These states can be interpreted either as being generated from two- or three-hadron dynamics. In particular, I will focus on $D_{1} (2420)$ and some predictions of three-body states obtained from $n\bar
hep-phnucl-th0 citations
09
Searching for long-lived ALPs with a laser-assisted optical dump
Tong Li🇨🇳 · Haolong Wang🇨🇳 · Man Yuan🇨🇳
The feeble interactions of light axion-like particles (ALPs) render them long-lived. Probing long-lived ALPs therefore demands facilities with a macroscopic decay volume to match their potentially long decay lengths, such as high-intensity beam dump experiments. An optical dump setup was proposed by utilizing hard photons from the collision of a high-energy electron beam and a high-intensity laser pulse. In this work, we revisit the probe of long-lived ALPs with MeV $\sim$ GeV mass via a laser-assisted optical dump. We consider the low-energy effective Lagrangian for ALPs incorporating the ALP-photon and ALP-fermion interactions. The scope of optical dump searches is extended to both the ALP-photon coupling induced Primakoff process and the Compton-like scattering via the ALP-electron coupling. We also investigate the correlation between Primakoff process and Compton scattering, and exhibit the interplay of two ALP couplings in light of optical dump experiment.
hep-ph0 citations
10
Spin-Resolved Decay of Axion-Like Particles into Electron--Positron Pairs in Strong Electromagnetic Fields
Xiaodan Mao🇨🇳 · Yue-Yue Chen🇨🇳 · Pei-Lun He🇨🇳
We investigate spin-resolved decay of an axion-like particle (ALP) into an electron--positron pair in an intense laser field. Using the Baier--Katkov quasiclassical operator formalism and the locally constant field approximation, we derive a compact analytic rate retaining finite ALP-mass effects and the lepton spin degrees of freedom. In the massless limit, the spin-summed rate has the same weak- and strong-field asymptotic scalings as the corresponding photon-induced pair-creation rate, while the pseudoscalar coupling induces distinct spin-resolved channels and spin correlations. A finite ALP mass reorganizes the spectrum across the vacuum threshold, producing purely field-induced pair creation below threshold and spin-dependent oscillatory modulations above threshold through the coherent interplay of vacuum and field-assisted contributions. The entanglement of the produced pair reflects the dominant production mechanism. Near the vacuum threshold in weak fields, the pair is nearly maximally entangled and singlet-like. Away from threshold, the reduced spin state becomes triplet-like, retaining a concurrence of $1/2$ when strong-field production dominates but becoming separable when vacuum decay dominates. These results identify spin-resolved spectra and entanglement as signatures of finite-mass and threshold effects in strong-field ALP searches.
hep-phquant-ph0 citations
11
Thermal Masses and Bubble-Wall Friction in Cosmological Phase Transitions
Carlo Branchina🇮🇹 · Stefania De Curtis🇮🇹 · Luigi Delle Rose🇮🇹 · Alessio Notari🇮🇹 · Giuliano Panico🇮🇹 · Matthew Starbuck🇬🇧
Bubble-wall friction controls the dynamics of first-order cosmological phase transitions. In Boltzmann-equation approaches, a major uncertainty arises from infrared gauge bosons, whose contribution is artificially enhanced in the massless approximation. We study the impact of thermal masses by including them consistently in both the Liouville operator and the collision integrals. Thermal masses suppress the source term for out-of-equilibrium perturbations while also reducing interaction rates. These effects largely cancel for top quarks, giving only percent-level changes, but they strongly suppress the infrared gauge-boson contribution, shifting the dominant momenta to scales of order the temperature. As a result, gauge bosons become subleading and wall velocities are close to those obtained from top-quark friction alone. We illustrate this in the singlet-extended Standard Model. Our results show that thermal masses reduce the sensitivity of friction calculations to the poorly controlled infrared sector of the plasma.
hep-phastro-ph.COhep-th1 citation
12
Possible hidden-bottom molecular pentaquarks from $P$ -wave $Λ_{b} B^{(*)} / Σ_{b}^{(*)} B^{(*)}$ interactions
Yu-Xin Wan🇨🇳 · Rui Chen🇨🇳 · Fu-Lai Wang🇨🇳 · Qi Huang🇨🇳
In this work, we perform a systematic investigation of the hidden-bottom molecular pentaquark states, encompassing both bound states and resonances, which originate from the $P$ -wave interactions between ground-state bottom baryons ( $Λ_{b}$ , $Σ_{b}^{(*)}$ ) and ground-state antibottom mesons ( $B^{(*)}$ ). Adopting the one-boson-exchange model and including the coupled-channel effects, we derive the effective potentials for all allowed quantum numbers $I (J^{P}) = 1/2 (1/ 2^{+})$ , $1/2 (3/ 2^{+})$ , $1/2 (5/ 2^{+})$ , $1/2 (7/ 2^{+})$ , $3/2 (1/ 2^{+})$ , $3/2 (3/ 2^{+})$ , $3/2 (5/ 2^{+})$ , and $3/2 (7/ 2^{+})$ . We then solve the coupled-channel Schrödinger equations to search for the bound-state solutions and perform the phase-shift analyses to identify resonance poles. Our results reveal a rich spectrum of positive-parity hidden-bottom molecular pentaquark candidates. In the isospin $I = 1/2$ sector, we find several loosely bound states and associated resonances, particularly in the $Σ_{b} B^{*}$ and $Σ_{b}^{*} B^{*}$ channels, where the coupled-channel dynamics plays an essential role in their formation. In the isospin $I = 3/2$ sector, the attraction is generally weaker because of the isospin factors. Nevertheless, we still obtain the loosely bound states and resonances, such as the $Σ_{b}^{*} B^{*}$ states with $J^{P} = 3/ 2^{+}$ , $5/ 2^{+}$ , and $7/ 2^{+}$ . The prominence of high-spin partial waves, for instance the $^{6} P_{J}$ components, underscores the importance of the spin-spin and tensor interactions. Our predictions provide a comprehensive and systematic spectrum of the $P$ -wave hidden-bottom molecular pentaquark states and offer clear guidance for future experimental searches at LHCb and Belle~II.
hep-ph1 citation
13
Precise Determination of the Proton's Gluon Cloud Geometry from HERA data
Tobias Toll🇮🇳 · Nahid Vasim🇮🇳
The transverse shape of the proton's small- $x$ gluon distribution is determined from exclusive $J / ψ$ photoproduction at HERA. We derive analytic expressions for the coherent and incoherent diffractive cross sections in the hotspot model at leading twist, enabling a global fit to all 104 available H1 and ZEUS data points, spanning three decades in $t$ , with $χ^{2} / ndf = 0.77$ . The gluonic hotspots are resolved into a perturbative Gaussian core of size 0.105(2) fm surrounded by a nonperturbative exponential halo of range 0.220(15) fm, in agreement with the gluon-field correlation length of the QCD vacuum and with the core-halo structure of flux tubes recently determined on the lattice. This shape is independent of $x_{I P}$ and of the assumed number of hotspots or hotspot repulsion. The gluonic geometry evolve only through a slow transverse diffusion of the hotspot centres with $α_{eff.}^{'} = 0.046 (28) GeV^{- 2}$ , while the incoherent cross section at small $∣ t ∣$ is dominated by shot-noise fluctuations at the order of one gluon per hotspot.
hep-ph0 citations
14
Model-Independent and Data-Driven Extraction of the Photon Distribution Function at the Electron--Ion Collider
Cong Li🇨🇳
In this work, we investigate a cross-section-ratio-based inversion method for extracting distribution functions at the Electron--Ion Collider (EIC). Starting from the general factorization formula $d σ = H \otimes f$ , we show that, for an appropriate bremsstrahlung process and suitably chosen differential observables, the convolution structure can be reduced to a multiplicative form. On this basis, we define the ratio $R = \frac{d σ _{exp}}{d σ _{hard}},$ where $d σ_{exp}$ is the experimentally measured differential cross section and $d σ_{hard}$ is a perturbatively calculable theoretical input. We then establish the relation between $R$ and the target distribution function $f$ . Finally, we investigate how the theoretical input $d σ_{hard}$ should be constructed when soft-photon radiation, finite-bin-width effects, and experimental acceptance are taken into account.
hep-phhep-th1 citation
15
Gluon GTMDs in the exclusive electroproduction of heavy-quark pairs
Mattia Bellotti🇮🇹 · Daniël Boer🇳🇱 · Cristian Pisano🇮🇹
We study exclusive electroproduction of heavy quark-antiquark pairs off nucleons in the framework of generalized transverse momentum dependent parton distributions (GTMDs) for gluons. The short-distance part of the process is treated at leading order in perturbative Quantum Chromodynamics and in first order in a collinear expansion, which allows identification with the description in terms of Generalized Parton Distributions (GPDs). For the results for the structure functions in terms of GTMDs and GPDs we consider only unpolarized (spin-averaged) nucleons, but include all possible azimuthal modulations that can arise. The presented results extend known expressions in the literature and are relevant for experimental studies of this exclusive process at the future Electron Ion Collider. Furthermore, we introduce a convenient decomposition of the gluon-gluon correlation matrix in terms of GTMDs, expanded in a Lorentz basis of symmetric traceless tensors obtained from the partonic momentum $k_{T}$ and the momentum transfer $Δ_{T}$ . The adopted notation for the GTMDs relates to the nucleon helicity states at the amplitude level, rather than to polarization states of the incoming nucleon or of the gluons, which makes it more transparent which contributions from helicity difference and helicity flip matrix elements can be accessed with unpolarized nucleon beams.
hep-ph0 citations
16
Relativistic corrections and high-energy resummation for exclusive heavy quarkonium photoproduction
Maxim Nefedov🇮🇱
The $O (v^{2})$ correction to the high-energy resummed coefficient function for the exclusive photoproduction of vector ( $1^{--}$ ) heavy quarkonia off hadrons is computed, thereby taking into account corrections of $O (v^{2} α_{s}^{n} ln^{n - 1} (x / ξ))$ . When expressed in terms of the physical vector-meson mass ( $M_{V}$ ) and the relative heavy-quark velocity ( $⟨ v^{2} ⟩$ ) using the Gremm-Kapustin relation, the computed correction turns out to be negligible at the scale $μ_{F} = M_{V}$ . However, it partially cancels the $μ_{F}$ dependence of the $O (v^{2})$ correction to the LO coefficient function in $α_{s}$ , thereby improving the robustness of the predictions.
hep-phhep-exnucl-exnucl-th0 citations
17
Radiative corrections in neutral-current (anti)neutrino elastic scattering at $GeV$ energies I: Nucleon targets
Yi Chen🇨🇳 · Oleksandr Tomalak🇨🇳 · Bing-Song Zou🇨🇳
We introduce radiative corrections in neutral-current (anti)neutrino-nucleon elastic scattering at $GeV$ energies within the effective field theory framework. We factorize cross sections into soft and hard functions, clarify the (anti)neutrino flavor dependence at both amplitude and cross-section levels, and improve the quantum chromodynamics (QCD) contributions to low-energy neutral-current processes. The radiative corrections at the single-nucleon level reach a magnitude comparable to the contributions from strange quarks. We also compare our results with the experimental data from BNL E734 and MiniBooNE collaborations, finding excellent agreements with the experimental data.
hep-phhep-exhep-latnucl-ex+10 citations
18
Inelastic Scattering Effects on Attenuation of Boosted Dark Matter
Guanhua Gu🇨🇳 · Liangliang Su🇩🇪 · Lei Wu🇨🇳 · Jin Min Yang🇨🇳
Earth attenuation is crucial for interpreting direct-detection constraints on boosted dark matter (DM), since scatterings with terrestrial nuclei can significantly modify the flux and energy spectrum reaching underground detectors. At boosted energies, inelastic nuclear channels beyond ordinary elastic scattering can become relevant, including quasi-elastic scattering, deep-inelastic scattering, and resonant scattering. In this work, we incorporate the resonant scattering of boosted dark matter (DM) off nuclei into the Earth-attenuation framework, in combination with the elastic, quasi-elastic, and deep-inelastic channels. We find that, in the heavy-mediator regime, resonant scattering can give a non-negligible contribution to the attenuation of boosted DM. Using the latest PandaX-4T data, we derive new constraints on the spin-independent boosted DM-nucleon cross section $σ ˉ_{n}$ .
hep-ph0 citations
19
$B \to X_{s} l^{+} l^{-}$ in the $μ$ from $ν$ Supersymmetric Standard Model
Xiao-Jie Hu🇨🇳 · Hai-Bin Zhang🇨🇳 · Tai-Fu Feng🇨🇳
We investigate the impact of new physics on the rare inclusive decay $B \to X_{s} l^{+} l^{-}$ within the framework of the $μ$ from $ν$ Supersymmetric Standard Model ( $μν$ SSM). The dominant contributions to the relevant Wilson coefficients and their corresponding particles are identified and analyzed. By performing a systematic scan over the relevant parameter space, we elucidate the underlying physical mechanisms governing these dominant contributions and demonstrate their consistency with the experimentally allowed regions. Experimental constraints from the decays $B ˉ \to X_{s} γ$ , $B_{s}^{0} \to μ^{+} μ^{-}$ , and the $125 GeV$ SM-like Higgs boson are also incorporated. We perform a systematic interference decomposition of the Wilson-coefficient contributions to the forward-backward asymmetry, identifying the $C_{7} C_{10}$ and $C_{9} C_{10}$ interference terms as the dominant contributions governing its behavior in both the low- and high- $q^{2}$ regions.
hep-ph0 citations
20
Spacelike-Collinear Scattering by the Method of Regions
Wen Chen🇨🇳 · Einan Gardi🇬🇧 · Rourou Ma🇨🇳 · Yao Ma🇨🇭 · Yang Zhang🇨🇳 · Zehao Zhu🇬🇧
We study the spacelike-collinear limit of gauge-theory scattering amplitudes using the Method of Regions. The corresponding splitting amplitude violates strict collinear factorisation through its dependence on the non-collinear partons. While the associated colour dependence has long been known, starting at two loops the splitting amplitude also acquires dependence on their kinematics. We show that this kinematic dependence originates from a unique hidden region present in the asymptotic expansion of the five-point amplitude in the spacelike-collinear limit, but absent in the timelike limit. More generally, we propose that hidden regions provide the mechanism by which crossing-related asymptotic limits cease to be analytically connected. We develop a general algorithm for the systematic identification of hidden regions. Applying it to the five-point amplitude in super Yang-Mills theory, we compute the hidden-region contributions to the complete set of basis integrals and recover the exact kinematically dependent factorisation-violating splitting amplitude. In momentum space, the hidden region is characterised by soft and Glauber loop momenta. This explains why the Wilson-line calculation captures the complete kinematic dependence, thereby accounting for the observed universality across gauge theories.
hep-phhep-th2 citations
21
Quantum spin correlations in $Z^{'}$ -mediated $t t ˉ$ production at future lepton colliders
ShivaSankar K.A. · Arindam Das🇯🇵 · Sanjoy Mandal🇰🇷
We study quantum spin correlations in top-quark pair production at future lepton colliders in the presence of a neutral gauge boson from anomaly-free general $U (1)$ extensions of the Standard Model. The process $ℓ^{+} ℓ^{-} \to t t ˉ$ , with $ℓ = e, μ$ , is analyzed through the spin-density matrix including $γ$ , $Z$ and $Z^{'}$ exchange and their interference. We focus on quantum-information observables such as the sufficient entanglement marker $D_{m i n}$ , concurrence, purity and the maximal Clauser-Horne-Shimony-Holt (CHSH) parameter, and compare their behavior with conventional rate information. Within the $U (1)_{X}$ framework, we consider several representative charge assignments to investigate how different chiral structures influence these observables, with particular emphasis on the $Z^{'}$ resonance region and polarized $e^{-} e^{+}$ collisions, where the two allowed initial-state helicity configurations can be selectively enhanced. We show that electron-beam polarization provides a direct handle on the left- and right-handed lepton charges of various $U (1)_{X}$ scenarios. These results demonstrate that quantum spin observables provide information complementary to cross sections and angular distributions in searches for chiral neutral gauge interactions.
hep-ph0 citations
22
Massive On-shell Splitting Functions in Spinor-Helicity Formalism
Yi-Ning Wang🇨🇳 · Chao Wu🇨🇳 · Jiang-Hao Yu🇨🇳
Collinear splitting functions govern parton evolution, parton showers, and resummation at high-energy colliders. While on-shell spinor-helicity methods have successfully yielded massless QCD splitting functions, a complete on-shell construction for massive particles, systematically incorporating finite-mass effects, is less developed. We present an on-shell constructive formalism for massive collinear splitting functions based on Soper-Weinberg collinear spinors, whose transformation properties follow from a light-front Galilean subgroup of the Poincaré group. Decomposing massive momenta and spinors with respect to fixed lightlike vectors $n$ and $n ˉ$ makes the expansion in the alignment regime $m < p_{T} ≪ p_{+}$ manifest. The leading-order structures are matched to massless three-point amplitudes, while an additional Higgs momentum along $n ˉ$ probes the subleading spinor components and relates them to massless four-point amplitudes. We derive the complete set of leading and subleading massive splitting functions for all Standard Model particles and establish a systematic matching dictionary between massless and massive coupling coefficients at both the three- and four-point levels. Higher-point splitting functions are obtained through the recursive bootstrap relation with a universal substitution rule as a consequence of the Galilean symmetry. This constructive framework extends naturally to effective field theory operators and higher perturbative orders, providing a flexible computational tool for precision collider physics and parton shower development.
hep-phhep-th0 citations
23
Next-to-next-to-leading order QCD corrections to pion (kaon)-induced exclusive Drell-Yan process
Yu Jia🇨🇳 · Bernard Pire🇫🇷 · Qin-Tao Song🇨🇳 · Guang Tang🇨🇳 · Zhe-Yu Wang🇨🇳
The high-energy pion and kaon beams proposed for future experiments at J-PARC offer a unique opportunity to investigate exclusive Drell-Yan processes induced by pions or kaons, which correspond to inverse deeply virtual meson production with $M = π, K$ . To facilitate precise comparisons between theoretical predictions and forthcoming experimental data, we calculate the next-to-next-to-leading order (NNLO) QCD corrections to the processes $π^{-} p \to γ^{*} (\to l^{+} l^{-}) + n$ and $K^{-} p \to γ^{*} (\to l^{+} l^{-}) + Λ$ . Our calculations are performed within the generalized parton distribution (GPD) factorization framework, accurate to leading twist in the generalized Bjorken limit ( $Q^{2} ≫ ∣ t ∣, Λ_{QCD}^{2}$ ). We find that the NNLO QCD corrections are substantial and positive; therefore, their inclusion is imperative for reliable theoretical predictions in confrontation with future experiments.
hep-phhep-exhep-latnucl-th0 citations
24
Particle production from bubble collisions
Anish Ghoshal🇬🇧 · Pratyay Pal🇺🇸 · Alessandro Strumia🇮🇹
Collisions of ultra-relativistic bubbles during cosmological phase transitions can produce particles much heavier than the transition scale. Previous analyses modelled this process as the off-shell decay of the scalar background. We show that its results parametrically overestimate hard particle production and depend on the gauge choice and the coordinate choice in field space. We propose an alternative formalism, analogous to the partonic description of high-energy collisions. In the ultra-relativistic limit, the colliding bubbles undergo nearly free passage and hard production arises from on-shell scatterings among the quanta constituting the Lorentz-contracted walls. We apply this approach to heavy scalar, fermion, and vector particle production, and study the implications for dark matter, leptogenesis, graviton production and primordial gravitational waves.
hep-phastro-ph.COhep-th5 citations
25
Evaporating cosmologically coupled black holes
Marco Calzà🇮🇹 · Davide Pedrotti🇮🇹 · Massimiliano Rinaldi🇮🇹 · Sunny Vagnozzi🇮🇹
Cosmologically coupled black holes (CCBHs), whose masses evolve in response to the cosmological expansion, have recently attracted significant theoretical and observational interest. Existing studies have treated CCBHs as purely classical objects, neglecting the effect of Hawking radiation (HR), which competes with the cosmological coupling (CC) mechanism. We take a first step towards studying evaporating CCBHs, adopting a quasi-adiabatic approximation in which the HR rate is evaluated at the instantaneous CCBH mass, and modeling the CC mechanism through the phenomenological scaling of the mass with the scale factor, $M \propto a^{k}$ . We show that, depending on the coupling strength $k$ , even late-time CC activation can significantly delay Hawking evaporation, or lead to asymptotic CC-dominated mass growth, with important implications. We set limits on the abundance of primordial CCBHs from $γ$ -ray observations, finding limits which are weaker than their uncoupled counterparts, as CCBHs are kept farther from the endpoint of evaporation for a longer time. Unlike standard primordial black holes, the CCBH formation and present-day masses no longer approximately coincide, even for formation masses $M_{form} ≳ 1 0^{15} g$ . Therefore, the same population of primordial CCBHs may be subject to evaporation limits through its past emission history, as well as to other limits (such as microlensing) through its present-day mass.
↳ astro-ph.COgr-qchep-phhep-th0 citations
26
Multiwavelength study of non-thermal emission in the Swift J1834.9-0846/W41 region
Manoel F. Sousa🇧🇷 · Rita C. Dos Anjos🇧🇷 · Vitor de Souza🇧🇷
We investigate the origin of non-thermal emission from the Swift J1834-0846/W41 region by modeling its broadband spectral energy distribution from radio to TeV energies within leptonic and lepto-hadronic frameworks using Markov Chain Monte Carlo sampling. Motivated by morphological studies of HESS J1834-087 suggesting a two-component TeV structure, we explore a single extended source scenario and a configuration comprising a central point-like component embedded within extended emission. Purely leptonic models are disfavored in both scenarios by unrealistically low magnetic field strengths, whereas lepto-hadronic solutions yield field intensities and non-thermal energy budgets consistent with an evolved supernova remnant undergoing efficient cosmic-ray acceleration. In the two-component scenario, hadronic interactions dominate the extended TeV emission from W41, while the central excess is well described by a leptonic magnetar wind nebula powered by Swift J1834-0846, implying a short initial spin period of $P_{0} ≲ 0.2$ s. Simulated observations with the Cherenkov Telescope Array Observatory show that 30 h exposures will discriminate between the two morphological configurations and extend spectral measurements beyond $\sim$ 10 TeV.
↳ astro-ph.HEastro-ph.SRhep-phJHEAp(2026)·0 citations
27
Pushing the Primordial Frontier: Cosmological Collider Signatures at Strong Mixing
Javier Huenupi🇺🇸 · Claudio Muñoz🇨🇱 · Gonzalo A. Palma🇨🇱 · Spyros Sypsas🇨🇱
We develop an analytic treatment of primordial non-Gaussianity in multifield inflation that is nonperturbative in the constant curvature--isocurvature mixing strength $λ$ . Using exact linear solutions for the coupled curvature perturbation $ζ$ and isocurvature perturbation $σ$ , we construct dressed propagators and derive exact integral representations for the tree-level bispectra generated by the interactions $ζ ˙^{2} σ$ , $ζ ˙ σ^{2}$ , and $σ^{3}$ . This formalism resums curvature--isocurvature transfer to all orders in $λ$ and applies for arbitrary values of the entropy mass $μ$ . We obtain closed-form expressions for the leading squeezed limit of the bispectrum contributions and recover the well-known cosmological-collider and quasi-single-field results in the weak-mixing limit. In the strong-mixing regime, where conventional transfer perturbation theory breaks down, we find that both the power spectrum and the bispectrum can be dramatically enhanced, giving rise to distinctive nonperturbative scaling laws for the reduced non-Gaussian amplitude. Together, these results open a new analytic window onto multifield inflation beyond the weak-coupling approximation and establish a framework for studying cosmological-collider signals, primordial-black-hole production, and loop corrections in strongly mixed inflationary dynamics.
↳ astro-ph.COgr-qchep-phhep-th5 citations
28
Relativistic Tidal Transitions of Saturated Kerr Boson Clouds
Yi-kun Li · Lang Cui🇨🇳
Rotating black holes can bind ultralight bosons in macroscopic clouds whose level structure is swept by the tidal field of a binary companion. Existing estimates of the resulting resonant transitions have largely used hydrogenic wave functions, even where the cloud grows most efficiently and the Kerr geometry appreciably deforms its quasibound states. I compute tidal transition matrix elements on the numerically determined saturation branches of the $∣211 ⟩$ , $∣322 ⟩$ , and $∣433 ⟩$ clouds. The calculation combines Kerr quasibound modes, their relativistic bilinear normalization, and an adiabatic uadrupolar perturbation of the Kerr metric. Across five $Δ m = - 2$ channels, the relativistic matrix element differs from its hydrogenic value by as much as $21.67%$ . Corrections above $10%$ persist when $99%$ of the cloud lies within $7%$ of the orbital separation. A component-resolved comparison attributes $78.7 - 82.5%$ of the logarithmic change to the radial mode profile and $13.3 - 16.2%$ to the bilinear normalization; the relativistic tidal geometry supplies a smaller additional correction. Exact Newtonian multipoles and an independent complex-contour construction confirm the quadrupole matrix elements. For resonances with intermediate Landau--Zener adiabaticity, the corrected matrix elements change the predicted cloud depletion by up to $13.7%$ . Relativistic cloud structure is therefore quantitatively important for binary histories that cross saturated-cloud resonances.
↳ astro-ph.GAgr-qchep-ph0 citations
29
A self-consistent Higgs-portal framework for dark matter--admixed neutron stars: Collider-motivated benchmarks meet multimessenger constraints
Adamu Issifu🇧🇷
We investigate dark matter (DM)-admixed neutron stars (NSs) within a self-consistent single-fluid relativistic mean-field framework by extending the Higgs-portal model with a massive $Z^{'}$ vector mediator. The resulting density-dependent repulsive interaction dynamically couples the baryonic matter (BM) and DM sectors, allowing the DM content to be characterized by the global particle fraction, $F_{χ} = N_{χ} / N_{B}$ , with the local DM density determined self-consistently as $n_{χ} = F_{χ} n_{B}$ , thereby eliminating the need for the externally prescribed DM Fermi momentum adopted in previous single-fluid models. Using the NL3 $ω ρ$ , DD2, and FSU2R EOSs, we show that increasing $F_{χ}$ systematically softens the nuclear equation of state (EOS), reduces the maximum NS mass by up to $\sim 29%$ , increases stellar compactness, and modifies the thermodynamic response of dense matter. We further derive exact analytical expressions for the adiabatic speed of sound, its density derivative, and the adiabatic index, providing a rigorous benchmark for assessing the causality and thermodynamic stability of DM-admixed EOSs. At the microscopic level, the BM--DM interaction is shown to be dominated by the repulsive $Z^{'}$ vector channel. Our framework establishes a direct connection between collider-motivated WIMP models and the multimessenger phenomenology of NSs, with potential implications for future gravitational-wave and X-ray observations.
↳ astro-ph.HEhep-phhep-thnucl-th0 citations
30
LQCDMaster: Agentic Scientific Computing for Lattice Quantum Chromodynamics Research
Haofei Gao🇨🇳 · Tingjia Miao🇨🇳 · Wenkai Jin🇨🇳 · Muhua Zhang🇨🇳 · Hanzhang Wang🇨🇳 · Jie Ran🇨🇳 · Jinxin Tan🇨🇳 · Zhentao Zhang🇨🇳 · Bo Tang🇨🇳 · Leiyi Li🇨🇳 · Jun Hua🇨🇳 · Xiangyu Jiang🇺🇸 and 3 other authors
Lattice quantum chromodynamics (LQCD) provides a first-principles framework for computing hadronic observables, but its practical use remains limited by the substantial expertise required to turn research motivation into reliable computing workflows. Here we present \textsc{LQCDMaster}, a tool-augmented, skill-guided and domain-specialized scientific computing agent that converts natural-language LQCD research tasks into executable PyQUDA computing workflows, including measurement scripts, job-submission artifacts, execution logs and numerical outputs. The system combines agentic planning, expert-annotated LQCD skills and a deterministic Wick-contraction tool to constrain the algebraically fragile components of code generation. We evaluate \textsc{LQCDMaster} on a benchmark at the forefront of scientific research, comprising 70 LQCD computing tasks, with observables covering local and nonlocal two-point functions, Wilson loops, meson and baryon three-point functions. The generated workflows exactly reproduce expert-written implementations in 63 of 70 tasks at machine precision, with three additional discrepancies attributable to convention mismatches. Across representative observables, the agent reduces implementation time from hours to minutes while preserving end-to-end numerical validation. Further, we present a typical case of \textsc{LQCDMaster}-driven exploration: a lattice computation of light-cone distribution amplitudes with diagonal Wilson-line, a quantity accessible with standard methods but never before computed, and computation of the spectrum of proton, deuteron, triton, hyperon, hyperdeuteron and hypertriton. This work pioneers the paradigm of agentic scientific computing by automating the end-to-end scientific computing workflows in lattice QCD research, lowering its barrier and facilitating the exploration and verification of non-standard scientific ideas.
↳ hep-latcs.AIhep-ph2 citations
31
High resolution Lyman-{\alpha} forest constraints on dark matter-neutrino scattering
Markus R. Mosbech🇩🇪 · Olga Garcia-Gallego🇬🇧 · Vid Iršič🇬🇧 · Matteo Viel🇮🇹 · Julien Lesgourgues🇩🇪
We present new constraints on models of dark matter interacting with neutrino, based on high-resolution Lyman- $α$ forest data. We perform a suite of full hydrodynamical simulations of these models, spanning a range of interaction strengths and thermal histories. We train an emulator on the simulation results. A Monte Carlo Markov Chain analysis yields an upper limit on the interaction strength of $u_{ν χ} \leq 1.5 \times 1 0^{- 8}$ (95% C.L.), which is the strongest direct bound to date on such interactions. Our results exclude previous hints of non-zero interactions presented in the literature. We furthermore compare our results to those obtained by mapping warm dark matter constraints to other models with suppressed small-scale structure, and find that these methods would overestimate the constraining power for this model.
↳ astro-ph.COhep-ph2 citations
32
One more radiative-recoil correction to the Lamb shift in muonium
Michael I. Eides🇺🇸 · Valery A. Shelyuto🇷🇺
We calculate radiative-recoil contribution of order $Z^{2} α (Z α)^{5} (m / M)^{2} m$ to the Lamb shift in muonium. This correction is due to insertion of radiative photons in the heavy line in the two-photon exchange diagrams. Our calculations are inspired by a new round of precise $1 S - 2 S$ and $2 S - 2 P$ experiments currently in progress.
↳ physics.atom-phhep-phPRD(2026)·0 citations
33
Cosmic string gravitational wave backgrounds at LISA: II. Reconstruction of conventional signals over astrophysical foregrounds
Androniki Dimitriou🇪🇸 · Daniel G. Figueroa🇪🇸 · Peera Simakachorn🇪🇸 · Isak Stomberg🇪🇸 · Bryan Zaldivar🇪🇸
We study the reconstruction of conventional cosmic-string signals with LISA in the presence of all major known astrophysical foregrounds expected in the LISA band. These include stellar-origin black-hole binaries (SOBHBs), galactic (WDs) and extragalactic (ExWDs) white dwarfs, extreme-mass-ratio-inspirals (EMRIs), and massive black-hole binaries (MBHBs). Using the Simulation-based Inference package GWBackFinder, we perform a joint inference on the LISA noise, foregrounds, and signal, across a range of injected string tensions $G μ$ . We find that reconstructing tensions with an error $≲ 10%$ requires values as large as $G μ ≳ 1 0^{- 11}$ , i.e. a factor $\sim 1 0^{5}$ larger than previous estimates with no foregrounds, and $\sim 1 0^{2}$ larger compared to estimates accounting only for SOBHB and WD foregrounds. This work is the second in a series initiated in Ref. arXiv:2508.05395, which aims to quantify LISA's ability to measure representative cosmic-string models.
↳ astro-ph.COgr-qchep-ph2 citations

Affiliations

first authorsco-authorsvia INSPIRE