HEP Phenomenology·hep-ph

Mon·Jul 20, 2026Monday·July 20, 2026

25 papers—16 primary·9 cross-listed

01
1D Luttinger Modes in Carbon Nanotubes as keV Dark Matter Detector
Xiuyuan Zhang🇺🇸 · Hao Chen🇨🇳
We propose metallic carbon nanotubes (CNTs) as a one-dimensional plasmon target for light dark matter (DM) direct detection. Unlike conventional gapless electronic targets, where DM primarily excites electron-hole pairs, the low-energy charge response of a metallic CNT is carried by a collective Luttinger-liquid mode. We compute the projected sensitivity for DM-electron scattering through heavy and light mediators, using benchmark thresholds motivated by quantum-capacitance-detector-like and superconducting-quasiparticle-amplifying-transmon-like readout. For an accumulated nanotube length $L_{CNT} = 1 0^{8} m$ , corresponding to milligram-scale single-wall CNT targets, we find competitive reach in the keV--MeV mass range. In the light-mediator case, the projected sensitivity can probe the cosmologically motivated freeze-in benchmark at keV masses. We also show that the one-dimensional geometry of aligned CNTs induces sidereal-day modulation, providing a handle for distinguishing a DM signal from approximately time-independent sensor backgrounds. These results establish one-dimensional collective modes as a new target class for sub-MeV DM detection. Existing progress in scalable CNT synthesis and superconducting quasiparticle sensing provides a promising experimental foundation, while realizing the proposed detector will require dedicated development of CNT--superconductor coupling and plasmon-to-quasiparticle conversion.
hep-phhep-ex0 citations
02
Multiboson Signatures of Doubly Charged Scalars at a Same-Sign Muon Collider
Mariana Frank🇨🇦 · Benjamin Fuks🇫🇷 · Chayan Majumdar🇨🇳 · Supriya Senapati🇨🇳
We investigate the sensitivity of a same-sign $μ^{+} μ^{+}$ collider to doubly charged scalars in the Type-II seesaw framework, focusing on the regime in which the doubly charged scalar decays dominantly into same-sign $W$ -boson pairs. Motivated by the $μ$ TRISTAN proposal, for a benchmark we consider a degenerate triplet spectrum at a center-of-mass energy of $2 TeV$ and an integrated luminosity of $1 ab^{- 1}$ . The signal process is studied in the fully hadronic $W$ -decay mode, leading to a characteristic $μ^{+} μ^{+} + 8 j$ final state. We develop a cut-based analysis based on high jet multiplicity and global hadronic $W$ reconstruction, and then improve its sensitivity with a multivariate strategy exploiting reconstructed $W$ observables, global event kinematics, multi-boson variables and spectator-muon information. The best-performing setup reaches a $2 σ$ sensitivity level for doubly charged scalar masses up to $425 - 430 GeV$ , extending the cut-based reach by a few tens of GeV. This indicates an improvement over the current LHC coverage, while also providing an independent probe based on a qualitatively different production mode and collider environment.
hep-ph0 citations
03
Muon Bremsstrahlung as a New Probe of Dark Sector at Neutrino Experiments
P. S. Bhupal Dev🇺🇸 · Bhaskar Dutta🇺🇸 · Aparajitha Karthikeyan🇺🇸 · Mudit Rai🇺🇸 · Zahra Tabrizi🇺🇸
We show that muon bremsstrahlung provides a new production mechanism for light new physics at accelerator neutrino experiments. The intense, highly collimated muon beam produced alongside the neutrino beam in meson decays provides a powerful source for the bremsstrahlung production of new physics when it impinges on the beam dump at these facilities. As a benchmark scenario, we consider a muonphilic scalar coupled to Heavy Neutral Leptons (HNLs) and show that muon bremsstrahlung enables the production of HNLs with masses beyond the kinematic reach of meson decays. Using this new production mechanism and focusing on HNL mixing with tau neutrinos, we find that ongoing (upcoming) short-baseline experiments like SBND (DUNE Near Detector) can probe previously unexplored parameter space for HNL masses up to $O (1) GeV$ through their decay into pions, $μ^{+} μ^{-}$ , and $e^{+} e^{-}$ final states at the detector. The resulting signals exhibit distinctive kinematics, allowing efficient discrimination from neutrino-induced Standard Model backgrounds. Our results demonstrate that the muon bremsstrahlung mechanism substantially extends the discovery potential of accelerator neutrino experiments for HNLs and other dark sector particles.
hep-ph0 citations
04
Charge-Odd Hyperon Polarization from Magnetic Spin Precession
Dushmanta Sahu🇲🇽 · Captain R. Singh🇮🇳
We demonstrate that polarized strange quarks undergo Larmor precession in the intense magnetic field produced in non-central heavy-ion collisions and as a possible source of charge-odd hyperon polarization. Strange and antistrange quarks carry opposite electric charges and therefore acquire opposite precession phases. This opposite spin rotation mixes the transverse and longitudinal polarization components, yielding measurable polarization splittings between $Λ$ and $Λ ˉ$ hyperons. For the magnetic-field evolution scenarios, the predicted splittings reach the sub-percent level and are within the experimentally accessible range at RHIC and the LHC energies. These charge-resolved hyperon polarization observables provide a direct probe of magnetic-field-driven spin dynamics of deconfined QCD matter at ultra-relativistic heavy-ion collisions.
hep-ph0 citations
05
Solar-System Abundances of $p$ -Nuclides Probe Collective Neutrino Oscillations in Supernovae
Alexander Friedland🇺🇸 · Derek J. Li🇺🇸 · Giuseppe Lucente🇺🇸 · Payel Mukhopadhyay🇺🇸 · Ian Padilla-Gay🇺🇸 · Amol V. Patwardhan🇺🇸
Direct evidence for collective neutrino oscillations in core-collapse supernovae remains elusive. We show that this quantum phenomenon leaves a footprint on the abundance pattern of proton-rich nuclides in the solar system. Modeling the $ν p$ -process using a $20 M_{⊙}$ progenitor, we map out the dependence of the total yields on the starting radius of the oscillations, self-consistently coupling hydrodynamics and nucleosynthesis. The oscillations boost key $p$ -nuclides ( $^{92, 94} Mo$ , $^{96, 98} Ru$ ) and long-lived $^{92} Nb$ by up to two orders of magnitude, bringing their abundances into agreement with the observations. The best match is found when oscillations commence within $10 km$ of the proto-neutron star surface, indicating fast collective oscillations.
hep-phastro-ph.HEastro-ph.SRnucl-th2 citations
06
PBH formation and Gravitational Waves as Multi-messenger Signals of First-order Phase Transitions
Bhaskar Dutta🇺🇸 · Cash Hauptmann🇺🇸 · Peisi Huang🇺🇸 · Adrian Thompson🇺🇸
The collapse of false-vacuum domains during first-order phase transitions in the early Universe may lead to primordial black hole (PBH) formation whose signatures form a multimessenger complement to gravitational wave (GW) production. We focus on PBH formation through the gravitational collapse of false-vacuum domains, described using a junction condition formalism. This formalism develops the Schwarzschild collapse criterion dynamically, avoiding the usage of critical overdensity thresholds in a post-inflationary Universe, and is driven solely by the vacuum energy enclosed within shrinking false-vacuum domains without the assistance of particle or domain wall interactions in the false vacuum. We study the parameter space of phase transitions and identify regions producing observable GWs, observable PBHs, or both simultaneously. We investigate this phenomenology in polynomial and classically conformal scalar field potentials as model benchmarks. We find that the scalar fields with vacuum expectation values in the range of 1-100 MeV have the largest model parameter space available for these multi-messenger signals, which are testable with upcoming GW observatories, searches for Hawking radiation, and gravitational lensing surveys.
hep-phastro-ph.COastro-ph.HE1 citation
07
JetCoRD: Reliability-Aware Cross-Experiment Distillation of Jet Taggers with Adaptive Corrective Representation
Liu-Long Gao🇨🇳 · Zheng-Kun Huang🇨🇳 · Xiao-Wei Jiang🇨🇳 · Jia-Feng Li🇨🇳 · Gong-Xing Sun🇨🇳
Modern jet taggers based on graph and transformer networks deliver state-of-the-art performance but are expensive to train and difficult to share across experiments. Knowledge distillation can in principle achieve model compression, but it rests on the assumption that the teacher model acts as a perfect tagger. This assumption fails to hold at high-purity working points, where the teacher itself exhibits a jet prediction error rate of approximately $10%$ to $30%$ . We introduce JetCoRD, the first cross-experiment distillation in HEP: an 82 k-parameter unified student distilling jointly from ATLAS GN2 (5 M params, 3 classes) and CMS ParT (2 M params, 10 classes). The central innovation is a single per-sample reliability signal $r_{i}$ that simultaneously weights the distillation loss, controls prototype-based teacher repair, and anchors the inference-time gate $g_{i}$ that mixes teacher and student logits. With only 82 k trainable parameters (1.2% of the combined 7 M teacher parameters), the student matches both teachers in overall accuracy and exceeds them at physics-actionable working points: $+ 4.3%$ on $b$ -vs- $c$ at $ε = 0.77$ , $+ 1.5%$ on $c$ -vs- $u$ at $ε = 0.30$ , $+ 1.6%$ on $T \to b q q$ at $ε = 0.5$ and $+ 1.4%$ on $H \to bb$ at $ε = 0.5$ . The reliability-coupled design is novel in HEP distillation and applicable wherever an imperfectly calibrated teacher must be compressed.
hep-ph0 citations
08
Enhanced Rydberg-Atom Superheterodyne Detection of Hidden-Photon Dark Matter on Chips
Xiaochen Li🇨🇳 · Bo Gao🇨🇳 · Shigeki Matsumoto🇯🇵 · Jie Sheng🇯🇵 · Chuan-Yang Xing🇨🇳 · Hong Ding🇨🇳
Although hidden-photon dark matter with masses above $1 0^{- 4} eV$ is well motivated by inflationary production, it remains largely unexplored by terrestrial experiments. Through kinetic mixing, hidden photons induce a weak oscillating electric field above $10 GHz$ . We propose to amplify this signal using a compact high-frequency distributed cavity and detect it with chip-scale Rydberg-atom superheterodyne spectroscopy. Combining resonant enhancement, large dipole moments of Rydberg atoms, and long-term stable integration, this approach can probe hidden-photon dark matter in the mass range $5 \times 1 0^{- 5} - 7 \times 1 0^{- 4} eV$ with sensitivities $3$ -- $4$ orders of magnitude beyond existing limits.
hep-phquant-ph0 citations
09
Nonequilibrium approach to heavy-quark transport
Juhee Hong🇰🇷
A nonequilibrium Green's function approach to heavy-quark transport is discussed within the framework of the Kadanoff-Baym equation. One- and two-loop self-energy diagrams with hard-thermal-loop resummed propagators are calculated in the real-time formalism. Under the quasiparticle approximation, the kinetic equation reduces to the Boltzmann equation that accounts for elastic scattering and medium-induced gluon emission from a single scattering. Numerical studies suggest that off-shell and memory effects in quark-gluon plasmas influence heavy-quark dynamics, particularly near the critical temperature.
hep-phnucl-th0 citations
10
Portal Matter and Scotogenic-like Dirac Neutrino Masses
Thomas G. Rizzo🇺🇸
Loops of portal matter (PM) fields, carrying both Standard Model (SM) and dark charges, can generate the necessary kinetic mixing (KM) between the ordinary and dark photons (DP) in vector portal scenarios thus allowing for interactions between visible and dark sector fields. Here we show that the field content of a previously considered model based on a partial $E_{6}$ -like UV-completion of such setups can generate light Dirac neutrino masses in the interesting range, $\sim 0.05$ eV, at the one-loop level similar to what happens in scotogenic dark matter (DM) scenarios. While general $E_{6} -$ like PM scenarios have been shown to be easily probed at colliders, such as the HL-LHC, uniquely testing this specific subclass of these setups in a direct fashion is found to be somewhat more challenging.
hep-ph0 citations
11
Gluon Saturation
Alfred H. Mueller🇺🇸
This is a review on gluon saturation. Sec. 1 gives a general introduction to the subject while Sec. 2 has a brief discussion of quark saturation. Sec. 3 covers gluon saturation in a semiclassical limit and the much more general context of QCD evolution. Surprisingly gluon occupancies in a high energy hadron can become arbitrarily large, much larger than $1/ α$ . Sudakov effects are introduced in Sec. 4 and reduce the maximum gluon occupancies to less than or equal to $(1/ α)^{3/2}$ in both fixed coupling and running coupling QCD. In Sec. 5 the role of saturation in coherent states in QCD is reviewed as well as brief discussions on nuclear shadowing, heavy ion collisions and Drell-Yan like processes are given.
hep-ph0 citations
12
$P_{c} (4312)$ , $P_{c} (4440)$ , and $P_{c} (4457)$ productions in $e^{+} e^{-}$ collisions
Quan-Yun Guo🇨🇳 · Dian-Yong Chen🇨🇳
In the present work, we propose to investigate the productions of $P_{c} (4312)$ , $P_{c} (4440)$ , and $P_{c} (4457)$ in the $e^{+} e^{-} \to p p ˉ J / ψ$ process by utilizing an effective Lagrangian approach, where $P_{c} (4312)$ is considered as $Σ_{c} D ˉ$ molecular state with $J^{P} = 1/ 2^{-}$ , while $P_{c} (4440)$ and $P_{c} (4457)$ are considered as $Σ_{c} D ˉ^{*}$ molecular states with $J^{P} = 1/ 2^{-}$ and $J^{P} = 3/ 2^{-}$ , respectively. For the $e^{+} e^{-} \to p ˉ P_{c} (4312)$ , $e^{+} e^{-} \to p ˉ P_{c} (4440)$ , and $e^{+} e^{-} \to p ˉ P_{c} (4457)$ processes, the cross sections are evaluated to be ( $27. 8_{- 17.9}^{+ 42.2}$ ) fb, ( $38. 7_{- 25.1}^{+ 58.6}$ ) fb, and ( $1.4 4_{- 0.93}^{+ 2.18}$ ) fb at $s = 6$ GeV, respectively, where the central values are estimated with $Λ_{r} = 2.5$ GeV, and the uncertainties are resulted from the variations of $Λ_{r}$ from 2.0 to 3.0 GeV. Considering that the $P_{c}$ states can decay into $J / ψ p$ , we estimate the cross sections for $e^{+} e^{-} \to p p ˉ J / ψ$ and the differential cross sections depending on the $J / ψ p$ invariant mass. At $s = 6$ GeV, the cross sections for $e^{+} e^{-} \to p p ˉ J / ψ$ are estimated to be ( $14. 7_{- 9.50}^{+ 22.2}$ ) fb. Moreover, our estimations indicate that the cross section resulted from the $P_{c} (4440)$ and $P ˉ_{c} (4440)$ intermediate states is dominant. In the $J / ψ p$ invariant mass spectrum, our estimations reveal that the peak structure between 4.42 and 4.46 GeV primarily originates from $P_{c} (4440)$ .
hep-phEPJC(2026)·0 citations
13
Minimalist Seesaw-Scotogenic Mechanism as a Source for Neutrino Physics
Eduardo Peinado🇲🇽 · Abdel Pérez-Lorenzana🇲🇽 · Isangel Toledo🇲🇽
We identify the smallest discrete flavor symmetry and minimal field content that can simultaneously account for neutrino masses and the dark sector in the context of the discrete dark matter. Minimality is achieved with a $D_{4}$ symmetry by adding three right-handed neutrinos and three scalar doublets. Within this framework, tree-level and one-loop contributions yield the observed solar--atmospheric mass splitings as well as the observed neutrino mixings. Furthermore, by including CP-violating phases, the model successfully accommodates both normal and inverted ordering. Spontaneous $D_{4}$ breaking leaves a residual $Z_{2}$ symmetry that stabilizes the dark matter candidate, with a predicted mass within the $50$ -- $200$ GeV range, consistent with LUX-ZEPLIN limits.
hep-ph0 citations
14
Learning Standard Model structure from LHC data with Riemannian flow matching
Midori Kato🇩🇰 · Kevin A. Urquía-Calderón🇩🇰 · Inar Timiryasov🇩🇰 · Oleg Ruchayskiy🇩🇰
In this work we demonstrate that a single transformer-based generative model can capture Standard Model structure spanning five decades of invariant mass, from the sub-GeV regime to the TeV continuum, a range that no single Monte Carlo sample covers. To achieve this we design \textsc{ShellFlow}, a Riemannian conditional flow matching model that, given the recorded event composition, generates each particle on its on-shell manifold. Its only physics priors are the on-shell condition and the invariant-mass formula. The model is trained on $\sim 1 0^{9}$ real $pp$ collision events from the ATLAS Open Data 13~TeV release and told nothing else. From a single training run, the model learns to reproduce all of the following: intra-particle kinematics, the dilepton resonances ( $J / ψ$ , $Υ$ , $Z$ ) at their PDG positions, the leptonic Weinberg angle, the $W$ and top-quark masses, and inter-particle correlations that enter no training objective. A substantial fraction of the Standard Model is thus learnable directly from recorded collision data.
hep-phcs.LGhep-ex0 citations
15
Order-reversed Kubo formulas in relativistic kinetic theory
Sangyong Jeon🇨🇦 · Juhee Hong🇰🇷 · Alina Czajka🇵🇱
Using the stress-energy tensor response functions obtained in the Anderson-Witting model of kinetic theory with non-zero mass, we verify that these response functions satisfy the required analytic conditions and are fully consistent with the recently derived Kubo formulas in Ref.[1].
hep-ph0 citations
16
Geometric scaling in elastic $pp$ collisions
Michał Praszałowicz🇵🇱
Geometric scaling was conjectured and observed at the ISR more than 50 years ago. We argue that it still holds at the LHC. We show that the dip-bump structures of the differential elastic cross-sections exhibit a remarkable regularity, namely that the ratio of the bump to dip positions is constant from 23 GeV to 13 TeV. Using crossing symmetry, analicity and the optical theorem, we identify the imaginary and real parts of the scattering amplitude. This allows us to compute the $ρ$ parameter and the ratio of the bump to dip values of the differential $pp$ cross-section. Finally, we discuss the energy dependence of the total elastic cross-section as compared to the total cross-section, and the violation of geometrical scaling outside the dip-bump region at the LHC.
hep-phPoS(2026)·0 citations
17
Searching for Folded Primordial Non-Gaussianity with Galaxy Surveys
Si-Xiang Yang🇺🇸 · Oliver H. E. Philcox🇺🇸
Large-scale structure provides a powerful probe of inflationary physics through primordial non-Gaussianity (PNG): the galaxy power spectrum depends on local PNG through scale-dependent bias, while the galaxy bispectrum depends sensitively on both equilateral and orthogonal PNG. In this paper, we study whether galaxy surveys can also probe folded PNG, whose shape is enhanced near $k_{1} + k_{2} - k_{3} \to 0$ . We consider three inflationary models with folded PNG, including excited initial states, imaginary speeds of sound, and dissipative inflation. These models fall into two classes: cutoff-regulated cases in which the folded-enhanced region has a power-law width, and dissipation-regulated cases in which the enhanced region is exponentially narrow. We develop a numerical pipeline for computing the corresponding PNG contributions to the redshift-space galaxy power spectrum multipoles and bispectrum monopole within the EFTofLSS. Using Fisher forecasts, we show that most of the constraining power on folded PNG comes from the galaxy bispectrum. For the cutoff-regulated models, nuisance parameter marginalization causes only a mild loss of information at large folded enhancement, but finite Fourier-space binning degrades constraints once the folded region becomes narrower than the bin width. For the dissipation-regulated models, the exponentially narrow folded enhancement is hard to resolve and the observable signal instead comes from the broader support of the template, leading to weaker binning dependence but larger overlap with the equilateral template. Our results show that folded PNG is a distinctive and promising target for galaxy bispectrum analyses, and the detectability depends on the width and morphology of the folded enhancement. The numerical pipeline developed in this work is general and can be used to study a wide class of non-separable primordial bispectra.
↳ astro-ph.COgr-qchep-phhep-th0 citations
18
Tunnelling out of Starobinsky inflation: Raising the spectral tilt
Jose A. R. Cembranos🇪🇸 · Jesús Luque🇪🇸 · Javier Rubio🇪🇸
We propose a hybrid realization of Starobinsky inflation in which the inflationary epoch ends through vacuum decay. The model consists of an effective two-field system with a metastable Starobinsky branch shifted with respect to the true one. During the observable stage, the inflaton slow-rolls along the false branch, until a first-order phase transition in an orthogonal direction connects it to the true branch and ends inflation abruptly. This old-inflation-like exit skips the last part of the would-be Starobinsky trajectory. As a result, the Cosmic Microwave Background pivot scale exits the Hubble radius further from the minimum of the false branch than in ordinary Starobinsky inflation, raising the scalar spectral tilt $n_{s}$ while preserving the characteristic small tensor-to-scalar ratio. This provides a simple way of moving Starobinsky inflation towards the high- $n_{s}$ region favoured by recent ACT-related combinations. The same vacuum transition leaves a stochastic gravitational-wave relic whose peak frequency is controlled by the tunnelling timescale and the subsequent reheating history.
↳ astro-ph.COgr-qchep-ph2 citations
19
Path optimization method for the sign problem: Insights from random matrix models
Kouji Kashiwa🇯🇵 · Yusuke Namekawa🇯🇵 · Hayato Takase
The path optimization method is applied to the Stephanov model and the chiral random matrix model, both of which share several properties with QCD, to mitigate the sign problem caused by the fermion determinant. The Stephanov model serves as a prototypical model of finite-density QCD, while the chiral random matrix model represents an ideal system featuring the Silver Blaze phenomenon. We show that the path optimization successfully improves the average phase factor in the Stephanov model at high chemical potential, reproducing the analytical results with reduced statistical errors. However, it fails to improve the average phase factor in the Stephanov model at low chemical potential, as well as in the chiral random matrix model. This tendency in the phase factor behavior seems to be closely related to the global sign problem.
↳ hep-lathep-ph0 citations
20
Non-thermal emission from the vicinity of the magnetar CXOU J171405.7-381031
Manoel F. Sousa🇧🇷 · Rita. C. Anjos🇧🇷
Magnetars are neutron stars with ultra-strong magnetic fields ( $B \sim 1 0^{14}$ - $1 0^{15}$ G) and are promising candidates for high-energy particle acceleration. We present a multiwavelength analysis of the region surrounding CXOU J171405.7-381031, a magnetar associated with the supernova remnant (SNR) CTB 37B. The broadband spectral energy distribution spanning radio to TeV energies is modeled using leptonic and lepto-hadronic scenarios, with particle populations constrained using Markov Chain Monte Carlo techniques. Within an SNR framework, both scenarios provide acceptable descriptions of the gamma-ray data. The purely leptonic model reproduces the overall spectral shape but slightly underestimates the highest-energy flux measured by H.E.S.S., whereas a lepto-hadronic interpretation offers an improved description above $\sim 10$ TeV, with inverse-Compton scattering dominating the GeV emission and neutral-pion decay contributing at the highest energies. The required proton energy ( $W_{p} ≳ 1 0^{51}$ erg) can be substantially reduced if the remnant interacts with a dense ambient medium. A magnetar wind nebula scenario can reproduce the broadband spectrum but is strongly disfavored by the observed source morphology. Simulated Cherenkov Telescope Array Observatory (CTAO) observations indicate that exposures of $\sim 50$ h will constrain the proton cut-off energy, enabling a decisive test of hadronic emission in this region.
↳ astro-ph.HEastro-ph.SRhep-phMNRAS(2026)·0 citations
21
Hanbury-Brown Twiss effect, squeezed gravitons and the photon correlations
Massimo Giovannini🇨🇭
Unlike the gravitational waves classically generated by moving macroscopic masses, the diffuse backgrounds of gravitons originate most likely from zero-point fluctuations of the gravitational field amplified by the evolution of the space-time curvature. The resulting entangled states lead to specific second-order correlation effects that could be eventually detected. For a quantitative analysis of this empirical expectation we scrutinize the interactions between the cosmic gravitons and the fundamental mode of a quantized electromagnetic field confined inside a closed optical resonator with perfectly-reflecting walls. We show that the Hanbury-Brown Twiss correlations of the photons are insensitive to the degrees of second-order coherence of the gravitons even barring for the exceedingly small couplings of the problem. Since the degree of second-order coherence of the photons does not reflect the correlation properties of the gravitons, the statistical properties of the gravitons (and their super-Poissonian statistics) cannot be inferred, even in principle, from the intensity correlations of the cavity modes.
↳ hep-thastro-ph.COgr-qchep-ph+10 citations
22
New Tools in the Landau Bootstrap
Piotr Bargieła🇬🇧 · Giulio Crisanti🇬🇧 · Craig Larkin🇬🇧 · Luke Lippstreu🇬🇧 · Andrew J. McLeod🇬🇧 · Maria Polackova🇬🇧 · Laura Walsh🇬🇧
We describe recent advances in our understanding of the analytic structure of Feynman integrals. In particular, we describe two new classes of constraints on such integrals, that identify discontinuities that either cannot be repeated, or that always give rise to the same result (no matter which other discontinuities are computed first). These new constraints hold at all orders in dimensional regularization, and provide us with new input for the Landau bootstrap, where information about the singularities and discontinuities of individual Feynman integrals is used to construct their functional form.
↳ hep-thhep-ph1 citation
23
Localized Vector Modes on Local Cosmic Strings
Sergio Alameda-Calvo🇪🇸 · Jose J. Blanco-Pillado🇪🇸 · Jose Queiruga🇪🇸
We investigate the dynamics of vector excitations localized on cosmic strings in the Abelian-Higgs model. These confined gauge field fluctuations behave as massive vector degrees of freedom propagating along the string. We show that they remain bounded for all values of the scalar self coupling $λ$ , including parameter regimes in which the previously studied conventional shape mode is no longer present. After determining their spectra and spatial profiles, we analyze their decay through nonlinear coupling to bulk radiation. Their amplitudes exhibit the characteristic power law relaxation associated with non-linear radiation. For sufficiently large $λ$ the scalar radiation channel becomes kinematically inaccessible and the decay is instead mediated by quasinormal modes which can be interpreted as Feshbach resonances of the string. We then study the full $3 + 1$ dimensional dynamics of the vector-excited string. Field theory simulations reveal a parametric instability between the vector mode and the Goldstone sector. In contrast to the shape mode, the vector mode resonantly excites both transverse directions simultaneously. In addition, we build an effective model that captures the instability and identifies the nonlinear couplings responsible for it. Our results show that vector excitations constitute a long-lived massive degree of freedom with a non-trivial role in the dynamics of local strings.
↳ hep-thastro-ph.COhep-ph0 citations
24
Large deviations for halos and voids: beyond perturbative non-gaussianities
Martin Teuscher🇫🇷 · Ruth Durrer🇨🇭 · Julien Grain🇫🇷 · Killian Martineau🇫🇷 · Aurélien Barrau🇫🇷
The excursion-set formalism provides a key connection between primordial density fluctuations and the abundance of cosmic structures such as dark matter halos and voids, traditionally assuming Gaussian random walks. In this work, we extend this framework to fluctuations whose distribution presents strongly non-Gaussian tails. Such tails are beyond the reach of perturbative approaches to primordial non-Gaussianity based on moment expansion. We address the problem with rigorous, analytical derivations relying on the large deviation principle, suited for the study of rare fluctuations. We derive new first-passage time distributions for random walks with non-Gaussian statistics and obtain updated predictions for the halo mass function. We also study the two-barrier problem relevant to cosmic void formation, leading to a new analytical prediction for the void size function, with improved accuracy on large scales. Our results demonstrate the potential of large deviation techniques as a bridge between inflationary scenarios, often leading to strongly non-Gaussian tails, and late-Universe observables.
↳ astro-ph.COhep-ph0 citations
25
Cosmological Evidence for Dark Axion-Dark Baryon Interactions from Apparent Phantom Crossing
Justin Khoury🇺🇸 · Meng-Xiang Lin🇺🇸 · Mark Trodden🇺🇸
Interactions between dark matter and dark energy can lead to an apparent phantom-crossing behavior that mimics the expansion history preferred by the latest cosmological observations from DESI baryon acoustic oscillations (BAO), Cosmic Microwave Background (CMB), and Type Ia supernovae (SNe Ia) data. In a previous paper [Khoury, Lin, and Trodden 2025 arXiv:2503.16415], we proposed a concrete particle physics realization of this idea, consisting of a strongly coupled dark sector in which a dark axion is coupled to dark baryons. In this paper, we investigate this idea further by comparing its predictions to the latest cosmological data. We implement the dark axion-dark baryon interaction model in a Boltzmann code and confront it with CMB, DESI DR2 BAO, and SNe Ia data. For the CMB+DESI DR2+DES-Dovekie combination, the best-fit model improves the fit relative to $Λ$ CDM by $Δ χ^{2} = - 14.48$ . The preferred solution exhibits a non-monotonic dark-matter mass evolution: the mass decreases between matter-radiation equality and recombination, while increasing over the BAO/SNe-sensitive epoch, leading to an apparent phantom crossing in an effective dark-energy description. Interestingly, the same dynamics produces an Early Dark Energy-like energy injection near matter-radiation equality, but in the data-preferred region this component is too small to raise $H_{0}$ enough to substantially reduce the current tension.
↳ astro-ph.COgr-qchep-phhep-th6 citations

Affiliations

first authorsco-authorsvia INSPIRE