HEP Phenomenology·hep-ph

Thu·Jul 2, 2026Thursday·July 2, 2026

37 papers—27 primary·10 cross-listed

01
Simulation of Axion-Induced Electromagnetic Signal Detection Using Plasmonic Metasurfaces and Diamond NV Centers
James L. Webb🇩🇰
The axion represents a strong candidate for weakly interacting dark matter. To date, high sensitivity lab based experiments and astrophysical observations have ruled out a substantial part of the axion mass and photon coupling parameter space. However, a challenge remains in searching for the presence of the axion in the higher mass range 0.01-1eV corresponding approximately to axion field oscillation at THz frequencies. This work investigates via numerical simulation the feasibility of a high sensitivity, lab-based axion sensor operating in this range, based on plasmonic electric field enhancement by a nanostructured metasurface, combined with heterodyne detection and quantum sensing via nitrogen-vacancy (NV) centers in diamond. Estimates of the sensor response to anomalous electromagnetic fields resulting from axion coupling are given using Ti/Au nanopillars on LiNb at axion mass corresponding to telecommunications wavelength ( $\approx$ 0.8eV, 196 THz). Finally, the possibility of sensing in the lower axion mass $<$ 10 $^{- 2}$ to 10 $^{- 1}$ eV range is explored using alternative materials, with CdTe as an example.
hep-phphysics.ins-detquant-ph0 citations
02
Precision Solar System Dynamics for Ultralight Dark Matter Search
Jonas Frerick🇮🇹 · Hyungjin Kim🇫🇷 · Felix Kling🇩🇪
Ultralight dark matter exhibits an order-one density fluctuation at the scale of its wavelength. This density fluctuation exists across the entire dark matter halo and interacts with stars and planets, perturbing their motion via gravitational interactions. We investigate the possibility of using precision solar system dynamics to search for ultralight dark matter. We examine this possibility with interplanetary radio range measurements. We show that the precision of current range measurements can probe ultralight dark matter at masses around $1 0^{- 15}$ eV, had its density in the solar system been $1 0^{5}$ larger than the so-called local dark matter density. This limit complements other constraints, such as the one from analyses of pulsar timing observations.
hep-phastro-ph.COastro-ph.EPastro-ph.IM1 citation
03
Putting Jet Substructure on Track(s)
Kyle Lee🇺🇸 · Ian Moult🇺🇸 · Wouter J. Waalewijn🇳🇱
One of the main advances in analysis strategies at the Large Hadron Collider (LHC) has been the ability to study the detailed structure of energy flow within high transverse momentum jets, a field referred to as jet substructure. Jet substructure has provided new ways to search for new physics, measure Standard Model parameters, and study the dynamics of the strong nuclear force. To push to the next level of precision, and to make measurements of increasingly subtle correlations, requires exquisite angular resolution achieved through the use of tracking information. In this paper we leverage recent progress in our understanding of factorization theorems and renormalization group techniques to present the first complete calculations of jet substructure observables at the LHC on tracks. We compute projected energy correlators up to four points at next-to-leading collinear logarithmic accuracy, matching the state of the art for jet substructure observables, but extending to tracks. This marks a significant step in enhancing the collider physics program, enabling precise and systematically improvable comparisons between experimental measurements and theoretical calculations, made possible by the exceptional angular resolution of tracking.
hep-phhep-exnucl-th3 citations
04
The left-cut for partial waves in terms of physical amplitudes
Alexandre Salas-Bernárdez🇪🇸
We derive a novel representation of the partial wave amplitude over the left-hand cut for $2 \to 2$ scattering. We express the left-hand cut of arbitrary isospin and angular momentum partial waves as an integral of right-hand cut imaginary parts. This formulation provides an explicit, exact extraction of the logarithmic branch cut structures, offering a valuable tool to systematically quantify left-hand cut uncertainties in unitarization methods such as the Inverse Amplitude Method or $N / D$ approaches.
hep-phhep-th0 citations
05
Production of Magic States via $Z$ Bosons and Dark Photons
Carlos Alvarado🇺🇸 · Alfredo Aranda🇲🇽 · César Bonilla🇨🇱 · Yahir Lua🇲🇽 · Ethan Rodríguez-Martínez🇨🇱
The production of magic states is studied in two settings. The first is the electroweak (EW) sector of the Standard Model (SM). The second is an extension featuring a new broken $U (1)$ gauge symmetry and a Dirac fermion charged under it. This setup resembles a dark $U (1)$ scenario, with the additional fermion playing the role of a dark matter candidate that annihilates into SM particles through its coupling to the new gauge boson. In the EW sector, the low-energy regime reproduces earlier magic production results obtained for Quantum Electrodynamics, whereas the high-energy and $Z$ -resonance regimes generate new magic distribution functions and non-trivially reorganize the stabilizer state classes, with Bhabha scattering exhibiting the strongest sensitivity to electroweak effects. Also, a subset of fixed stabilizer states is identified, for which the magic distributions remain unchanged across the different energy regimes. In the dark sector, the main effect of the new massive mediator is the appearance of new magic distributions functions for Moller-like, Bhabha-like, and inverse pair-annihilation processes in the low-energy limit. These reach the maximal magic value at the SM-to-dark fermion mass ratios $m_{f} / m_{χ} \to 0$ and $m_{f} / m_{χ} \to 1.83929$ .
hep-phquant-ph1 citation
06
Soft-Dimuon Signature from Two-Component Scalar Dark Matter at the LHC
Alexander Belyaev🇬🇧 · Manimala Chakraborti🇬🇧 · Shu Chen🇬🇧 · Atri Dey🇸🇪 · Venus Keus🇮🇪 · Rakhi Mahbubani🇭🇷 · Stefano Moretti🇬🇧
We explore the potential of the Large Hadron Collider to probe a two-component scalar dark matter scenario in the opposite-sign dimuon plus missing transverse energy final state, accompanied by a hard jet. The signal features a soft dimuon system with an invariant mass well below $m_{Z}$ . We consider a 3-Higgs Doublet Model with one active and two inert scalar doublets, where a $Z_{2} \times Z_{2}^{'}$ symmetry stabilises the lightest neutral scalar in each inert sector, yielding two scalar DM candidates. The relevant parameter space is mapped in terms of the two DM masses and the mass splittings between each DM candidate and its corresponding next-to-lightest scalar state. We perform a detector-level Monte Carlo analysis and design a dedicated cut-based selection, including a transverse-mass requirement adapted to the signal topology. For a representative benchmark, we obtain $S / B ≃ 9.8$ and a statistical-only significance of $S / B = 1.35$ at Run 3 with $L = 300 fb^{- 1}$ , increasing to $S / B = 4.93$ under a statistical-only extrapolation to $L = 4 ab^{- 1}$ . Before the full selection, the two dark sectors generate a double-bump structure in the dimuon invariant-mass distribution. After the cuts optimised for inclusive sensitivity, however, this feature is not statistically robust enough to establish the two-component origin of the signal. The benchmark is underabundant and is interpreted as a subdominant two-component DM scenario, while the collider analysis remains independent of its cosmological abundance. Although the numerical study is carried out in the I(2+1)HDM, the results are applicable to weakly interacting sectors with similar electroweak associated production and cascade decays, where a heavier state separated from the DM candidate by less than $m_{Z}$ produces a soft muon pair via an off-shell $Z$ boson.
hep-ph0 citations
07
Classifying the hidden-charm pentaquarks via a flavor mixing scheme
Kan Chen🇨🇳 · Bo Wang🇨🇳
In this work, we propose a scheme to classify the molecular states consisting of ground single-charm baryons ( $Λ_{c}$ , $Ξ_{c}$ , $Σ_{c}^{(*)}$ , $Ξ_{c}^{' (*)}$ , $Ω_{c}^{(*)}$ ) and $D ˉ^{(*)} / D ˉ_{s}^{(*)}$ mesons. Within this framework, all considered baryon-meson systems are categorized according to the flavor components of their light degrees of freedom. We briefly illustrate how this classification scheme can consistently explain the experimentally observed $P_{c}$ and $P_{cs}$ states. This framework also predicts the existences of single-strange and double-strange hidden-charm bound states. The attractive interactions of these states arise from channel mixing between $Σ_{c}^{(*)} D ˉ_{s}^{(*)}$ and $Ξ_{c}^{' (*)} D ˉ^{(*)}$ for single-strange systems, and mixing between $Ξ_{c}^{' (*)} D ˉ_{s}^{(*)}$ and $Ω_{c}^{(*)} D ˉ^{(*)}$ for double-strange systems, respectively. Using parameters fitted from the measured $P_{c}$ and $P_{cs}$ states, we systematically present the predicted mass spectra for these single- and double-strange hidden-charm bound states.
hep-phhep-ex0 citations
08
Fermion Mixing Matrices and the Exceptional Jordan Algebra
Bishnu Gupta Teli🇮🇳 · Tejinder P. Singh🇮🇳
We extend the exceptional-Jordan spectral framework for fermion mass hierarchies to the problem of quark and lepton mixing. Following the companion mass paper~\cite{Teli:2026jgr}, each fermion sector is associated with a Hermitian element of $J_{3} (O_{C})$ , where adjacent square-root mass ratios are obtained from cubic ladders in $Sym^{3} (3)$ . Here, these ratios are used as inputs to an adjacent-edge lift from spectral hierarchy data to two-generation mixing angles. The lift is derived from a Fritzsch-type two-state texture~\cite{Fritzsch:1977za, Fritzsch:1979zq} and should be regarded as an effective bridge ansatz rather than a theorem of the Jordan spectrum alone. The exact CP-transport input is supplied by the companion CP Letter~\cite{GuptaTeli:2026aqf}. In the quark sector, the octonionic ladder operator $α_{2}$ generates a real local rotor in the $(e_{1}, e_{3})$ plane, and the up- and down-sector local Cabibbo-edge amplitudes are complex conjugates, giving the exact local law $ϕ_{12} = - 2 χ$ . This is a transport-level Cabibbo-rung phase law, not by itself a prediction of the standard CKM Dirac phase. With the fitted companion mass ratios, the minimal two-angle extraction from the measured $∣ V_{u s} ∣$ gives an effective Cabibbo-block phase $ϕ_{12} ≃ 105. 7^{\circ}$ ; this number is a bridge diagnostic, while the balanced octonionic rotor remains the distinguished quadrature reference point. The $(2, 3)$ sector requires a phenomenological normalization $κ_{23} ≃ 0.56$ , and the direct $(1, 3)$ element remains a long-edge bridge problem. [Truncated]
hep-ph3 citations
09
Sub-eikonal stress and model dependence of the small- $x$ gluon D-term
Lei Wang🇨🇳
The leading-eikonal small- $x$ dipole gives a compact representation of the gluon momentum form factor $A_{g} (t)$ . We show that the same information is not sufficient to determine the gluon stress form factor $C_{g} (t)$ , and hence the gluon D-term. The reason is kinematic and operatorial: in a Drell-Yan frame $A_{g} (t)$ is projected by $T_{g}^{++}$ , whereas $C_{g} (t)$ is projected by the symmetric-traceless transverse stress $T_{g}^{ij}$ . This stress projection first appears through next-to-eikonal fields and is represented by gauge-invariant stress-decorated Wilson lines containing $F^{i -}$ , $F^{ij}$ , or equivalent sub-eikonal target fields. We construct this operator and match it to the local energy-momentum tensor at tree level, obtaining an operator-level no-go statement: the ordinary dipole $S_{x} (b_{⊥}, r_{⊥})$ , or a saturation profile $Q_{s}^{2} (x, b)$ , does not by itself determine the sign of the small- $x$ gluon D-term. We then give a finite-correlation response model in which a positive kernel generates an anti-aligned response $F^{i -} = - ϵ R_{NE} F^{i +}$ , so that $Λ_{NE} > 0$ and $D_{g} (0) < 0$ within that response class. A Gaussian benchmark and numerical scans over Gaussian, Woods-Saxon, power-edge, and McLerran-Venugopalan (MV)-inspired profiles show a stable negative forward D-term for this anti-aligned model, together with the expected core-shell pressure pattern. The gluon D-term is therefore a next-to-eikonal stress probe, not a universal leading-eikonal saturation observable.
hep-ph0 citations
10
Leading-twist to higher-twist generalized parton distributions of the pseudoscalar mesons at non-zero skewness
Abi Jebarson A🇮🇳 · Navpreet Kaur🇮🇳 · Harleen Dahiya🇮🇳
We investigate the multidimensional partonic structure of spin-0 mesons, specifically the pion and the kaon, by evaluating their complete set of eight generalized parton distributions (GPDs) up to twist-4. Utilizing the light-front quark model (LFQM) with the Brodsky-Huang-Lepage (BHL) prescription, we compute these distributions in the kinematically rich non-zero skewness ( $ξ \neq = 0$ ) domain, strictly within the DGLAP region, $x \in [ξ, 1]$ . To construct a three-dimensional tomographic picture, we perform Fourier transforms of the momentum-space GPDs to obtain the impact parameter dependent parton distribution functions (IPDPDFs) in the transverse plane and the corresponding diffraction patterns in the longitudinal coordinate space. The numerical results explicitly reveal the consequences of $SU (3)$ flavor symmetry breaking, as the strange quark in the kaon dynamically shifts spatial localizations compared to the lighter up quarks. We also observe that while higher-twist correlations exhibit massive amplitude scaling in the pion, they are heavily suppressed by the larger macroscopic mass of the kaon.
hep-ph0 citations
11
Finite modular Coleman-Weinberg inflation
Yoshihiko Abe🇯🇵 · Komei Goto🇯🇵 · Tetsutaro Higaki🇯🇵 · Junichiro Kawamura🇯🇵 · Tatsuo Kobayashi🇯🇵
We propose a modular symmetric inflationary model based on a Coleman--Weinberg potential generated by integrating out heavy vector-like quarks that couple to the complex modulus field $τ$ through modular forms. In this framework, the imaginary part of modulus $τ$ plays the role of the inflaton, while the real part is identified with a heavy axion. We show that the model successfully explains the current cosmological observations. We further discuss reheating through modulus-dependent gauge kinetic functions and the cosmology of the axion. The axion oscillation dominates over the Universe after the reheating via inflaton decay, and then it decays before Big Bang Nucleosynthesis in the viable parameter region. The quantum fluctuation of the axion can be of order $O (1) %$ of that of the inflaton, which would induce isocurvature perturbations that may be detectable in future observations.
hep-phastro-ph.COhep-th0 citations
12
Effective Color Dipole Approach to Color Transparency in $ρ^{0}$ Electroproduction
Tae Keun Choi🇰🇷 · Kook-Jin Kong🇰🇷 · Byung-Geel Yu🇰🇷
We investigate nuclear transparency in exclusive $ρ^{0}$ electroproduction on $^{12}$ C and $^{56}$ Fe nuclei within a multi-channel final-state interaction (FSI) framework that explicitly incorporates the kinematic decay length effect (DLE) arising from the short-lived $ρ^{0} \to π^{+} π^{-}$ decay. The purely kinematic and nuclear mechanisms prove insufficient to account for the CLAS data: the DLE alone cannot generate the observed $Q^{2}$ -dependent enhancement, and the inclusion of nuclear shadowing further deepens the disagreement, so that a compensating reduction of the in-medium attenuation -- the hallmark of color transparency (CT) -- is required. To incorporate the color dynamics of the initially compact $q q ˉ$ configuration, we replace the empirical Quantum Diffusion Model (QDM) ansatz for the initial interaction cross section $σ_{h} (Q^{2})$ of the point-like configuration (PLC) by an effective Color Dipole Model (CDM) boundary condition, evaluated through a normalized dipole-weighted $γ^{*} \to ρ^{0}$ transition overlap. Combined with the standard linear QDM transport at an effective in-medium expansion scale $Δ m^{2} = 0.3$ ~GeV $^{2}$ , the CDM boundary condition reproduces both the magnitude and the $Q^{2}$ dependence of the data for both targets. A $χ^{2}$ analysis quantifies the pronounced separation between the non-CT and CT-based descriptions and thereby supports the onset of color transparency in the $ρ^{0}$ channel beyond what kinematic decay-length effects can accommodate.
hep-phnucl-th0 citations
13
The Negative- $Σ Σ ˉ$ Angular-Parameter Puzzle in $J / ψ$ and $ψ (2 S)$ Decays
Chao-Qiang Geng🇨🇳 · Xiang-Nan Jin🇨🇳 · Chia-Wei Liu🇨🇳
Experimental measurements of $J / ψ$ and $ψ (2 S)$ decays to octet baryon pairs reveal a negative- $Σ Σ ˉ$ puzzle in the angular distributions: $α_{Σ}^{J / ψ} < 0$ , whereas the other measured $J / ψ$ octet channels and the corresponding $ψ (2 S)$ channels have positive angular parameters. We show that an $SU (3)_{F}$ -exact singlet description is strongly disfavored in a $χ^{2}$ fit, giving $χ^{2} ≃ 1 0^{5}$ . By contrast, a reduced scenario in which a common final-state interaction mixes the $S$ - and $D$ -wave amplitudes, with an antisymmetric direct octet and a full diagonal $S$ - $D$ rescattering block, gives $χ^{2} = 4.21$ for two nominal degrees of freedom. The negative $Σ Σ ˉ$ angular parameter is traced to the pattern of the rescattered $S$ - and $D$ -wave amplitudes. The apparent large $SU (3)_{F}$ -breaking effect is decomposed into three ingredients: the fitted $D$ -wave source is much larger than the $S$ -wave source, the breaking remains modest when normalized to the $D$ wave, and $D \to S$ rescattering transfers the $SU (3)_{F}$ -breaking effect from the $D$ wave into the small $S$ -wave baseline, where it appears large. The largest remaining pull comes from the $ψ (2 S) \to N N ˉ$ angular input, motivating a renewed experimental check of $ψ (2 S) \to n n ˉ$ .
hep-phhep-ex1 citation
14
QCD sum-rule determination of the axial-vector mixing angle in the $B_c(1P)$ sector
T.M. Aliev🇹🇷 · S. Bilmis🇹🇷 · M. Savci🇹🇷
We determine the mixing angle between the $1^1P_1$ and $1^3P_1$ axial-vector states in the $B_c(1P)$ sector using QCD sum rules. The analysis gives $\theta_{B_c(1P)}=(43.3\pm0.2)^\circ$, indicating sizable mixing between these two states. We also compare our result with theoretical studies available in the literature.
hep-phhep-ex0 citations
15
Gluon radiation from a QCD antenna with realistic parton-medium interactions
Carlota Andrés🇫🇷 · Liliana Apolinário🇵🇹 · Néstor Armesto🇪🇸 · André Cordeiro🇵🇹 · Fabio Domínguez🇪🇸 · Pablo Guerrero-Rodríguez🇪🇸 · José Guilherme Milhano🇵🇹
The spectrum of coherent gluon radiation from a quark-antiquark pair undergoing multiple scatterings within a colored medium is central for understanding in-medium parton cascades. However, current efforts are constrained by reliance on a number of approximations, such as the harmonic oscillator approximation, that are only valid within limited regions of phase space. In this paper, we circumvent this problem by expressing the full in-medium gluon emission spectrum as a set of differential equations that can be solved numerically. This formalism, previously applied to the case of medium-induced radiation off a single color charge, allows to resum medium interactions to all orders while employing realistic scattering models. The resulting angle and energy distributions of emitted gluons serve to illustrate the breakdown of color coherence across the entire accessible phase-space, and constitute a definite step towards a higher-precision description of jet observables.
hep-phnucl-th0 citations
16
Charmonium-nucleon femtoscopy as a possible probe of the nucleon gravitational form factor
Ren Ejima🇯🇵 · Daisuke Fujii🇯🇵 · Mamiya Kawaguchi🇺🇸
We investigate the charmonium-nucleon interaction, focusing on its connection with the internal structure of the nucleon encoded in the gravitational form factors. To describe this interaction, we employ an effective potential based on the QCD multipole expansion within the leading chromoelectric dipole approximation. In this framework, the potential is expressed in terms of the energy and pressure distributions inside the nucleon. We first construct these distributions from the gravitational form factors fitted to lattice-QCD data. The remaining model parameters are then fixed by requiring that the resulting $J / ψ$ - $N$ potential reproduce the HAL QCD potential outside the short-distance region, as well as the scattering phase shift estimated from the HAL QCD data. Based on this potential, we evaluate the $J / ψ$ - $N$ correlation function and further investigate the $ψ (2 S)$ - $N$ system. We then examine the sensitivity of these correlation functions to the nucleon $D$ -form factor.
hep-ph2 citations
17
KineticXGPU: A Tensorized Collision Operator for Dark-Sector Self-Scattering
Esau Cervantes🇵🇱
In this work, we present KineticXGPU, a PyTorch-based implementation of the $2 \to 2$ elastic self-collision operator for dark-sector momentum distributions. The discretized collision operator can be expressed as tensor contractions and is therefore well suited for GPUs. As an application, we study a two-source freeze-in scenario in which the final distribution can develop a bimodal shape. We show that increasing the strength of elastic self-interactions progressively erases this structure and drives the distribution toward a Maxwell-Boltzmann distribution. We compare the phase-space formulation with a set of fluid equations that couple the number density and velocity dispersion. We also compare CPU and GPU runtimes and demonstrate the computational advantage of the tensorized approach. The code is publicly available on GitHub.
hep-ph0 citations
18
70 years of Double-Logarithmic Approximation
B.I. Ermolaev🇷🇺
Existence of Double-Logarithmic (DL) contributions to scattering amplitudes in QED was discovered by V.V. Sudakov in 1956 and total summation of DL contributions to electron-photon scattering resulted in appearance of famous Sudakov exponentials. Then, thanks to contributions of V.G. Gorshkov, V.N. Gribov, G.V. Frolov and L.N. Lipatov, the pattern of calculations in Double- Logarithmic Approximation (DLA) was constructed. Since then, DLA has become one of basic ways of describing various high-energy processes in the framework of QED, QCD and theory of EW interactions. In the present paper, we remind the history of DLA and present a brief overview of application of DLA to various objects like form factors, scattering amplitudes, DIS structure functions.
hep-phhep-th1 citation
19
Rethinking Partial Widths: Unitary Mixing and the $Δ (1232)$ Pole Residue
S. Ceci🇭🇷 · R. Omerović🇧🇦 · H. Osmanović🇧🇦 · M. Uroić🇭🇷 · B. Zauner🇭🇷
The extracted $π N$ partial decay width of the $Δ (1232)$ systematically exceeds its total width ( $2∣ r ∣ > Γ$ ). We demonstrate this anomaly is a natural consequence of S-matrix unitary mixing. Because exact multi-channel shadow poles are distant and model-dependent, we utilize a heuristic elastic model -- treating the overlapping $Δ (1600)$ as fully elastic -- to isolate the core mechanism. We show that evaluating a perturbing S-matrix at a state's complex pole systematically inflates the residue magnitude. This proof of principle confirms complex residues reflect global amplitude topology rather than isolated intrinsic properties, challenging naive interpretations of branching fractions.
hep-ph0 citations
20
Exploring the neutron momentum distribution in nuclei through $γ n \to π^{-} p$ at an electron-positron collider
Zi-Wei Yan🇨🇳 · Shu-man Hu🇨🇳 · Wei Wang🇨🇳 · Ji Xu🇨🇳 · Fu-Sheng Yu🇨🇳 · Ya-Teng Zhang🇨🇳
The neutron momentum distribution is essential both for reliably extracting fundamental free neutron observables from nuclear measurements and for probing the tensor force via the high-momentum neutron fraction, which is crucial to the theoretical understanding of short-range correlations (SRCs). In this work, we investigate this distribution by studying the $γ n \to π^{-} p$ process at an electron-positron collider, proposing to utilize the beryllium beam pipe at the Beijing Spectrometer III (BESIII). The cross sections for this process on both deuteron and beryllium targets are calculated within the impulse approximation framework. We also evaluate the effective luminosity of the photon flux from radiative Bhabha scattering, taking into account the distribution of target materials within the BESIII experimental setup. Our results show that tens of thousands of events can be generated at BESIII, offering the potential for precise measurements of the neutron momentum distribution. These findings suggest that electron-positron colliders could play a valuable role in elucidating nuclear structure and advancing our understanding of nonperturbative QCD, offering promising new avenues for both particle and nuclear physics.
hep-ph0 citations
21
Dark matter energy exchange in stars orbiting supermassive black holes
Stephan A. Meighen-Berger🇦🇺 · R. Andrew Gustafson🇺🇸 · Nicole F. Bell🇦🇺 · Jayden L. Newstead🇦🇺 · Sandra Robles🇺🇸 · Ian M. Shoemaker🇺🇸
Stars on tight orbits around the supermassive black hole at the Galactic Center pass through regions where the dark matter~(DM) density may be strongly enhanced. We compute the orbit-averaged DM-induced energy exchange for S4714 as an example. It is a star on an exceptionally close and relativistic orbit around Sagittarius~A*. For a spiked dark matter profile, the exchange reaches the stellar luminosity at $σ_{χ p} \sim 1 0^{- 36} cm^{2}$ for MeV-GeV masses and $σ_{χe} \sim 5 \times 1 0^{- 38} cm^{2}$ for sub-MeV masses, opening a new annihilation-free route toward dark-star phases. These cross sections lie within the range predicted by freeze-in scenarios and are consistent with cosmic-ray--boosted and solar-reflection dark matter constraints.
hep-phastro-ph.HE1 citation
22
Higher-order effects in amplitude-assisted polarisation extraction with machine-learning techniques
Juan M. Cruz-Martinez🇪🇸 · Jakob Linder🇩🇪 · Mathieu Pellen🇩🇪 · Giovanni Pelliccioli🇮🇹 · Emanuele Re🇮🇹
With increasing experimental precision, the prospect of extracting the polarisation of electroweak gauge bosons is becoming particularly attractive. To this end, regression and classification procedures based on precise and accurate theoretical predictions are becoming increasingly important. In this work, we present the first amplitude-assisted regression procedure at next-to-leading-order accuracy in QCD, supplemented with parton-shower effects, using machine-learning techniques to extract the rate of longitudinal-boson production in high-energy collisions. Several neural-network architectures are presented and benchmarked against a standard random-forest regressor, demonstrating the robustness of the results for di-boson production at the LHC.
hep-phhep-ex2 citations
23
Quantum entanglement of photon pairs at proton-proton colliders
Yue Pan🇨🇳 · Yipin Wang🇨🇳 · Leyun Gao🇨🇳 · Qiang Li🇨🇳 · Chen Zhou🇨🇳
Diphoton systems, with photon polarizations measurable at low energies, serve as ideal qubits and were first used to demonstrate quantum entanglement. However, due to the current absence of dedicated polarimeters at high-energy colliders, the entanglement properties of diphoton systems remain largely unexplored at the high-energy frontier. Studying quantum entanglement at the high-energy frontier, where particle colliders serve as a natural relativistic laboratory, helps us better understand the quantum nature and seek new physics. In this letter, we propose a novel method to measure the entanglement of diphoton systems at proton-proton colliders. The photon spin analyzing power arises from the Bethe-Heitler process occurring in the tracker, where photons scatter off nuclei to produce electron-positron pairs whose joint angular distribution encodes the polarization of the diphoton system. Simulation results show that, under HL-LHC conditions, the statistical significance of quantum entanglement in the Higgs $\to γ γ$ process is $0.007 σ$ , while measuring the continuum diphoton process $q q ˉ \to γ γ$ alone can reach about $1.5 σ$ .
hep-ph2 citations
24
The Quantum Statistical Approach to Parton Distributions upgraded with recent experimental data
Claude Bourrely🇫🇷
The Quantum Statistical Parton Model has been successful over the years explain a great set of unpolarized and polarized experimental data. to With the advent of the Marathon and SeaQuest experiments an upgraded version is required to maintain the validity of the model. Moreover, in order to clarify the role of the thermodynamical potentials, the main parameters of the model, we examine the variation of the proton and the neutron entropy with the potentials.
hep-ph0 citations
25
Shedding light on the nature of $ϕ (2170)$ with the parton and hadron cascade model PACIAE
Jian Cao🇨🇳 · Wen-Chao Zhang🇨🇳 · Bo Feng🇨🇳 · Ya-Hui Hou🇨🇳 · An-Ke Lei🇨🇳 · Zhi-Lei She🇨🇳 · Hua Zheng🇨🇳 · Li-Lin Zhu🇨🇳 · Dai-Mei Zhou🇨🇳 · Yu-Liang Yan🇨🇳 · Ben-Hao Sa🇨🇳
The nature of $ϕ (2170)$ remains open. We simulate its production in $e^{+} e^{-}$ collisions at $s = 4.95$ GeV using PACIAE 4.0, which sequentially generates the final partonic state (FPS) and the final hadronic state (FHS). While previous studies have interpreted $ϕ (2170)$ as an $ss s ˉ s ˉ$ or a $u u ˉ s s ˉ$ state, the $U (1)$ anomaly coupling allows non-strange quarks to couple to a vector $s s ˉ$ component via soft-gluon interactions. This motivates us to also explore the $d d ˉ s s ˉ$ tetraquark configuration. In addition, we consider $ϕ (2170)$ as an excited strangeonium state, an $s s ˉ g$ hybrid state, a $Λ ˉ Λ$ bound state, and a $ϕ K^{+} K^{-}$ resonance state. The strangeonium, hybrid, and tetraquark candidates are formed by coalescing their constituent partons in the FPS using the dynamically constrained phase-space coalescence model. The $Λ ˉ Λ$ and $ϕ K^{+} K^{-}$ states are produced via recombination of their constituent hadrons in the FHS. We calculate the orbital angular momentum quantum number of each candidate in its rest frame and perform spectral classification. Given $J^{P C} = 1^{--}$ , $ϕ (2170)$ can be interpreted as a $D$ -wave $s s ˉ$ , a $P$ -wave $s s ˉ g$ , a $P$ -wave $u u ˉ s s ˉ / d d ˉ s s ˉ / ss s ˉ s ˉ$ , an $S$ -wave $Λ ˉ Λ$ , or an $S$ -wave $ϕ K^{+} K^{-}$ state. The yields of the $D$ -wave $s s ˉ$ , $P$ -wave $s s ˉ g$ , $u u ˉ s s ˉ$ and $d d ˉ s s ˉ$ states are of order $1 0^{- 4}$ ; those for the $S$ -wave $Λ ˉ Λ$ and $ϕ K^{+} K^{-}$ states are of order $1 0^{- 5}$ ; while the $P$ -wave $ss s ˉ s ˉ$ yield is of order $1 0^{- 6}$ . Moreover, significant discrepancies are observed in the rapidity distributions and the $p_{T}$ spectra among the various candidates. These discrepancies could serve as valuable criteria for unraveling the nature of $ϕ (2170)$ .
hep-phnucl-th0 citations
26
HyperFORM -- a FORM package for parametric integration with hyperlogarithms
Adam Kardos🇭🇺 · Sven-Olaf Moch🇩🇪 · Oliver Schnetz🇩🇪
HyperFORM brings the parametric integration of hyperlogarithms, weighted by rational prefactors, into the symbolic-manipulation system FORM. It ports the capabilities of Erik Panzer's Maple package HyperInt, capitalizing on FORM's speed with bulky algebraic input and on its ability to spread a single calculation across many processor cores. We keep the description of the method brief and concentrate instead on how the package is organized and driven: a fully self-contained program for the three-loop zigzag period serves as a worked illustration, and timing measurements for zigzags through six loops gauge its present reach. HyperFORM is released openly and applies to a broad class of problems, the evaluation of Feynman integrals prominently among them.
hep-ph1 citation
27
The cleanest of them all: NLO electroweak corrections to vector-boson scattering into doubly polarised ZZ pairs at the LHC
Ansgar Denner🇩🇪 · Robert Franken🇩🇪 · Santiago Lopez Portillo Chavez🇩🇪 · Daniele Lombardi🇮🇹 · Giovanni Pelliccioli🇮🇹
We present the first calculation of the next-to-leading-order electroweak corrections to vector-boson scattering into doubly polarised Z bosons at the LHC in the fully leptonic decay channel. The production and decay of the two polarised Z bosons are consistently modelled in the double-pole approximation, separating polarisation states at the amplitude level and including factorisable real and virtual electroweak corrections. Doubly polarised and unpolarised signals are investigated and confronted with off-shell results. A broad analysis, including results at integrated and differential level, is carried out in a realistic, CMS-inspired fiducial setup. Our study paves the way to upcoming analyses with LHC Run-3 and High-Luminosity data as well as to further phenomenological investigations.
hep-phhep-exJHEP(2026)·1 citation
28
Running into tension: primordial black holes from ultra-slow-roll inflation, spectral running, and the Hubble tension
Miguel A. Sabogal🇮🇹 · Antonio J. Iovino🇦🇪 · Sunny Vagnozzi🇮🇹
Single-field ultra-slow-roll (USR) inflation is among the most studied mechanisms for primordial black hole (PBH) formation. When a non-stationary inflection point close to CMB scales is present, these models predict a negative spectral running ( $α_{s} < 0$ ), whose magnitude increases with the PBH mass. This is in tension with recent hints for positive running from Atacama Cosmology Telescope (ACT) Cosmic Microwave Background (CMB) data. However, inflationary parameters inferred from CMB data are sensitive to the assumed pre-recombination expansion history, which is precisely where new physics motivated by the Hubble tension should operate. Focusing on axion-like early dark energy (EDE) as a benchmark, we investigate the effect of such pre-recombination new physics on $α_{s}$ , and hence on the viability of USR PBH models, in light of state-of-the-art CMB data from Planck, ACT, and the South Pole Telescope, together with Baryon Acoustic Oscillation data from DESI DR2. Our analysis therefore provides an updated set of constraints on $α_{s}$ and the running of the running $β_{s}$ . For most dataset combinations, moving from $Λ$ CDM to EDE increases the inferred $α_{s}$ : once the acoustic angular scale $θ_{s}$ is fixed, EDE increases the diffusion-to-acoustic angular scale ratio $θ_{d} / θ_{s}$ , and the shift in $α_{s}$ compensates this extra damping by increasing small-scale power. In this sense, tension calls for tension: taking the Hubble tension seriously as an indication for new physics strengthens the challenges faced by USR PBH models. More broadly, our analysis stresses that inflationary model selection using CMB-inferred inflationary parameters such as $n_{s}$ and $α_{s}$ may be premature, especially until the Hubble tension, and more generally the pre-recombination expansion history, is understood.
↳ astro-ph.COgr-qchep-phhep-th8 citations
29
An Analytical Toy Equation of State for Neutron Stars Consistent with Current Observations
Tian-Shun Chen🇨🇳 · Xiao-Ding Zhou🇨🇳 · Kilar Zhang🇨🇳
Fast analytic and semi-analytic studies of neutron stars often require an equation of state that is convenient to evaluate while producing relativistic stellar sequences compatible with current multimessenger constraints. We construct such a benchmark by scanning a smooth double polytropic relation for the energy density as a function of pressure, $ϵ^(p^) = a_{1} p^^{Γ_{1}} + a_{2} p^^{Γ_{2}}$ . The parameters are selected with filters based on massive pulsars, tidal deformability from the binary-neutron-star event GW170817, and NICER mass-radius measurements. A single polytropic baseline scan finds no model passing all filters, whereas a double-polytrope scan identifies a viable region. A curve-integral score, evaluated against public NICER and GW170817 posterior data sets, is then used to choose benchmark equations of state within this region. The selected representatives support $M_{m a x} = 2.44$ -- $2.49 M_{⊙}$ , with $R_{1.4} ≃ 11.3$ km and $Λ_{1.4} = 485$ -- $512$ , and remain causal on the stable branch. This compact analytic family provides reference cases for relativistic stellar-structure tests at current observational scales.
↳ astro-ph.HEgr-qchep-ph0 citations
30
QFT as a set of ODEs: higher dimensions
Fabiana De Cesare🇮🇹 · Manuel Loparco🇮🇹
Correlation functions of local operators in Quantum Field Theory (QFT) in Anti-de Sitter space (AdS) are completely fixed by the QFT data: the set of scaling dimensions $Δ_{i}$ and OPE coefficients $C_{ij k}$ of the boundary operators, and the bulk-boundary (BOE) coefficients $b_{i}^{Φ^}$ encoding how bulk fields decompose into boundary operators. In this work, we generalize the ordinary differential equations (ODEs) that govern the variation of the QFT data under a bulk relevant deformation, originally derived for AdS $_{2}$ \cite{Loparco:2026fki}, to the cases of AdS $_{3}$ and AdS $_{4}$ . We demonstrate that these flow equations natively capture the mechanism of merger-annihilation when a boundary operator hits marginality, as well as level repulsion when different $Δ_{i}$ 's approach each other. Furthermore, we address the practical implementation of the framework: we propose substituting the ODE for the OPE coefficients with the crossing equation for greater efficiency, and we observe that Padé approximants dramatically improve the convergence of the sums over boundary operators, at least in free theories. Altogether, these advances lay the groundwork for the future application of the flow equations to the study of strongly coupled QFTs in AdS and their flat space limits.
↳ hep-thhep-ph2 citations
31
Escape from Ostrogradsky via Hidden Ghost Parity
Sam Bateman🇬🇧 · Neil Turok🇬🇧
We present a counterexample to Ostrogradsky's famous "no go" theorem as usually interpreted in quantum field theory (QFT), namely a four-derivative, UV-complete QFT with a consistent perturbative expansion which describes high energy scattering processes. We carefully quantize the theory on an $indefinite$ space of states - a Krein space - using covariant methods which ensure perturbative causality and unitarity (in the form of the optical theorem) to all orders. We generalize the Born rule to Krein spaces and prove that all tree level transition probabilities are positive in spite of the presence of ghosts. A key role in the proof is played by a hidden "ghost parity" symmetry which becomes explicit when the theory is embedded in a two-derivative, two-field $O (1, 1)$ -symmetric perturbative field theory.
↳ hep-thgr-qchep-phmath-ph+13 citations
32
From geometry to phenomenology
Stefan Weinzierl🇩🇪
Precision calculations in quantum field theory rely very often on perturbation theory and thus on the computation of Feynman integrals. Feynman integrals are also fascinating objects from a mathematical point of view and show deep connections to algebraic geometry. Cutting-edge Feynman integrals usually have geometries of "mixed" type, for example parts of it may correspond to a K3-surface, other parts may correspond to curves of a certain genus and the simplest parts correspond to points. In this talk I will discuss how to extract the geometric information from a Feynman integral and how this information can be used to compute more efficiently Feynman integrals. Non-trivial mixed geometries already occur in $2 \to 2$ -processes at two-loops, like Drell-Yan, Bhabha and Moller scattering.
↳ hep-thhep-ph1 citation
33
New Bounds on Exotic Long-Range Spin-Spin Interactions
Nathan B. Clayburn🇺🇸 · Andrew Glassford🇺🇸 · Thomas Uelmen🇺🇸 · Ashley R. Kyung🇺🇸 · Yana Boneva🇺🇸 · Saif Salim🇺🇸 · Alison S. Weiss🇺🇸 · Flanagan Waldherr🇺🇸 · Claire Carlin🇺🇸 · Stephen K. Peck🇺🇸 · Larry R. Hunter🇺🇸
Many proposed extensions to the Standard Model of particle physics introduce new bosons that can mediate forces which couple to particle spin. Here we describe a search for such forces coupling spin-polarized neutrons and protons in our magnetometer to spin-polarized electrons within Earth. We measure these interactions by varying the orientation of an optical $^{199}$ Hg- $^{133}$ Cs free-precession comagnetometer mounted upon a precision rotation platform. From these measurements, we establish upper bounds on the dimensionless coupling constants associated with the axial-axial potential $V_{2}$ and the axial-vector potential $V_{11}$ as a function of the force's range $λ$ . For the electron-neutron and electron-proton potential $V_{2}$ at infinite range, we find $∣ g_{A}^{e} g_{A}^{n} ∣ \leq 3.0 \times 1 0^{- 48}$ and $∣ g_{A}^{e} g_{A}^{p} ∣ \leq 3.0 \times 1 0^{- 47}$ . For $V_{11}$ , we find our most stringent bounds to be $∣ g_{A}^{e} g_{V}^{n} ∣ \leq 2.2 \times 1 0^{- 25}$ and $∣ g_{A}^{e} g_{V}^{p} ∣ \leq 2.2 \times 1 0^{- 24}$ at $λ \approx 1 0^{3}$ km. Our results represent an improvement over previous results by up to a factor of 17 and set the most stringent bounds on long-range axial-axial and axial-vector couplings between electron spins and neutron and proton spins.
↳ physics.atom-phhep-ph1 citation
34
Spin Femtoscopy: A Framework for Revealing Genuine Spin Correlations
Kehao Zhang🇨🇳 · Xuan Wang🇨🇳 · Xiaofeng Luo🇨🇳
Spin correlations are among the most fundamental quantum observables in many-body systems, yet they remain difficult to access experimentally in relativistic heavy-ion collisions. Existing spin measurements, including hyperon polarization and vector-meson spin alignment, have revealed important single-particle spin phenomena, but genuine two-particle spin correlations in the produced hadronic system remain largely unexplored. Here we propose spin femtoscopy, a framework for accessing genuine two-particle spin correlations through spin-resolved femtoscopic measurements. The key principle is that different two-particle spin configurations can give rise to different femtoscopic correlation functions because of quantum statistics, spin-dependent final-state interactions. Using $ΛΛ$ pairs as a proof of principle, we exploit the self-analyzing weak decay of $Λ$ hyperons to construct spin-sensitive femtoscopic correlation functions with different singlet and triplet admixtures. We show that these observables provide experimental access to the spin-state populations of the pair and allow genuine spin correlations to be separated from spin-dependent femtoscopic mixing caused by quantum statistics and final-state interactions. This work extends femtoscopy from a probe of source geometry and final-state interactions to a framework for revealing the quantum spin structure of strongly interacting matter.
↳ nucl-thhep-exhep-phnucl-ex+13 citations
35
Gradient Flow Renormalization Schemes for Composite Fermion Operators
Matthew Black🇬🇧 · Anna Hasenfratz🇺🇸 · Oliver Witzel🇩🇪
We introduce gradient flow (GF) normalization prescriptions for fermionic composite operators in which the flowed fermion wavefunction renormalization factor is fixed nonperturbatively using either the partially conserved axial charge or the conserved vector current. The resulting $A$ and $V$ schemes are defined through standard flowed two-point correlation functions and therefore avoid the backward-flow construction required by local ringed-scheme definitions. In the short-flow-time limit, the $A$ and $V$ schemes can be matched to $MS$ using known ringed-scheme short-flow-time expansion (SFTX) coefficients. We show how these schemes can be implemented through ratios of two-point correlation functions, leading to simple nonperturbative determinations of renormalization factors, anomalous dimensions, and evolution factors which connect lattice-accessible flow times to shorter flow times where perturbative matching is reliable. We illustrate the method with RBC-UKQCD domain-wall fermion ensembles, including a GF determination of the ratio of matching factors $Z_{V} / Z_{A}$ , and a new GF determination of the renormalized strange quark mass.
↳ hep-lathep-ph0 citations
36
Isospin-breaking effects in inclusive hadronic $τ$ data for the muon $(g - 2)$ from first principles
Mattia Bruno🇮🇹 · Taku Izubuchi🇺🇸 · Christoph Lehner🇩🇪 · Aaron S. Meyer🇺🇸 · Julian Parrino🇩🇪 · Xin-Yu Tuo🇺🇸
The knowledge of isospin-breaking effects in hadronic $τ$ decays is required for a high-precision determination of the Hadronic-Vacuum-Polarization contribution to $(g - 2)_{μ}$ from experimental $τ$ data. In this work we present a strategy for their calculation in a fully inclusive setup from first-principles Lattice QCD+QED simulations. We separate radiative corrections in three infrared safe classes, which we study individually. We provide analytic expressions for their effects in the initial state and propose a strategy for final-state corrections directly in Euclidean space. We also examine the non-factorizable contributions and highlight the challenges associated with their analytic continuation from Euclidean to Minkowski space. By studying short-distance corrections in the context of momentum schemes, we provide a prescription for the renormalization of the individual terms at first order in the ispospin-breaking parameters.
↳ hep-lathep-ph1 citation
37
Inclusive $B ˉ_{s} \mapsto X_{s ˉ c} ℓ ν ˉ$ decays from lattice QCD: computational strategy and a first physical result
Alessandro De Santis🇩🇪 · Antonio Evangelista🇨🇾 · Gael Finauri🇮🇹 · Roberto Frezzotti🇮🇹 · Giuseppe Gagliardi🇮🇹 · Paolo Gambino🇮🇹 · Marco Garofalo🇩🇪 · Christiane Franziska Groß🇩🇪 · Bartosz Kostrzewa🇩🇪 · Vittorio Lubicz🇮🇹 · Lorenzo Maio🇮🇹 · Francesca Margari🇮🇹 and 7 other authors
We present a strategy to compute the inclusive decay rate for the process $B ˉ_{s} \mapsto X_{s ˉ c} ℓ ν ˉ$ from first principles in lattice QCD. The physical decay rate is obtained from the interpolation of non-perturbative lattice data, obtained at lighter than physical heavy meson masses ( $M_{B ˉ_{s}}^{max} = 4.3$ GeV), with the Operator Product Expansion predictions, which become exact in the limit of infinitely heavy quarks. We also present a new method for the computation of the required lattice four-point correlators, which represents a considerable improvement over the state-of-the-art on the subject. We show the effectiveness of the strategy by performing the calculation on a subset of the available $n_{f} = 2 + 1 + 1$ physical-point Extended Twisted Mass Collaboration (ETMC) gauge ensembles. Our current determination of the inclusive decay rate has a 7% total error, that is dominated by uncertainties due to the relatively limited configuration ensembles considered herein, and can be significantly reduced in the near future.
↳ hep-lathep-ph2 citations

Affiliations

first authorsco-authorsvia INSPIRE