HEP Phenomenology·hep-ph

Mon·Aug 24, 2026Monday·August 24, 2026

28 papers—18 primary·10 cross-listed

01
Tunneling from a Slowly Rolling Multifield Background Using Tadpole Subtraction
Masaki Yamada🇯🇵
We study semiclassical tunneling in scalar field theories with slowly evolving homogeneous backgrounds. We formulate the problem by combining tadpole subtraction with an adiabatic expansion: the former maps the rolling system to an instantaneous multi-field tunneling problem, while the latter systematically tracks the slow evolution of the background. This formulation is particularly useful for tunneling during slow-roll inflation, where the tunneling direction may be transverse to the rolling inflaton direction. For a time-reflection-symmetric bounce on a fixed on-shell geometry, we show that the real tunneling exponent receives no direct correction linear in the rolling velocity. The tunneling rate nevertheless drifts along the rolling trajectory because the frozen tadpole-subtracted potential evolves. We also find that the exponent approaches a finite but nonanalytic limit as the tangential curvature vanishes, suggesting that a weakly tachyonic tangential direction can yield an exponent of the same order.
hep-phastro-ph.COgr-qc0 citations
02
Poles in $π N$ scattering from forward dispersion relations and revised total cross-section data
José Ramón Peláez🇪🇸 · Pablo Rabán🇪🇸 · Jacobo Ruiz de Elvira🇪🇸
We present a model-independent calculation of $π N$ forward dispersion relations and their analytic continuation to the complex plane, using a revised set of $π^{\pm} p$ total cross-section data up to 3 GeV, and Regge asymptotics above. Up to that energy, we find four stable poles for each isospin combination. The lightest pole in the $I = 3/2$ channel corresponds to the $Δ (1232)$ resonance, while the lightest in the $I = 1/2$ channel corresponds to the Roper resonance, even though the latter is imperceptible in the data. We extract their pole parameters and the parameter difference between the $Δ^{0}$ and $Δ^{++}$ , without relying on a partial-wave analysis. The remaining poles cannot be identified with a single resonance each. They are not artifacts but the combined effect of multiple resonances unresolved by total cross-section data alone. Finally, we write sum rules relating the residues of these constituent resonances to the residues of the poles extracted from the dispersive representation.
hep-phhep-exhep-latnucl-th0 citations
03
First Search for Ultraheavy Dark Matter Using a Magnetically Levitated Particle
Dennis G. Uitenbroek🇳🇱 · Dorian W. P. Amaral🇪🇸 · Juehang Qin🇺🇸 · Jurriaan Langendorff🇳🇱 · Andrew Gingerich🇺🇸 · Tjerk H. Oosterkamp🇳🇱 · Christopher D. Tunnell🇺🇸
We present the first search for ultraheavy dark matter using a magnetically levitated particle. The POLONAISE experiment uses a milligram-scale ferromagnet levitated in a superconducting trap, admitting a force sensitivity of $0.07 fN H z^{- 1/2}$ and resolving impulses as small as $1 TeV / c$ . Treating every candidate impulse as a possible dark matter event, we set optimum-interval upper limits on the neutron coupling $α_{n}$ for dark matter interacting through a new light mediator. For dark matter masses $1 0^{6} GeV / c^{2} - 1 0^{15} GeV / c^{2}$ and mediators lighter than $30 meV / c^{2}$ , we exclude couplings as low as $α_{n} = 3.2 \times 1 0^{- 9}$ at $95%$ confidence level and set leading constraints on the dark matter-neutron cross section for composite dark matter. Our results extend levitated sensing beyond the mass reach of optical levitation by seven orders of magnitude into the ultraheavy dark matter frontier.
hep-phhep-exquant-ph1 citation
04
Muon Capture on the Proton with Heavy-Light Currents
Evan Combes🇺🇸 · Emanuele Mereghetti🇺🇸 · Lucas Platter🇺🇸
We construct a non-relativistic Lagrangian that describes muon-proton electroweak interactions. We determine the leading order coefficients by matching onto the theory with non-relativistic nucleons and relativistic leptons. The most impactful $O (α)$ corrections to those coefficients are determined by matching the non-relativistic amplitudes for capture of a free muon on a proton to the corresponding relativistic one. We use our non-relativistic effective field theory framework to calculate the capture rate in muonic hydrogen, thereby including radiative corrections of order $α$ and up to order $1/ m_{μ}$ . Using results for the Fermi coupling previously derived in EFT, we obtain singlet and triplet capture rates of $Γ (^{1} S_{0}) = 724.07 \pm 5.45 s^{- 1}$ and $Γ (^{3} S_{1}) = 11.55 \pm 0.18 s^{- 1}$ , respectively.
hep-phnucl-th0 citations
05
Intensity-Frontier Signals of Warped Extra Dimensions
Doojin Kim🇺🇸 · Deepak Sathyan🇺🇸 · Ankur Verma🇺🇸
Can warped extra dimensions first appear at the intensity frontier rather than as TeV-scale resonances at colliders? We explore this possibility in extended warped models in which gravity propagates to a deep infrared region with warped scale $Λ_{IR} \sim O (MeV)$ , producing a densely spaced Kaluza-Klein (KK) graviton tower. We develop a benchmark photon-portal realization in which a visible vector sector reaches an intermediate GeV-scale brane, while the Higgs sector remains associated with a higher warped scale. The resulting graviton-photon couplings are controlled by wave-function overlap in the extra dimension, so the production rate is not governed simply by an independent mass and coupling as in conventional light-mediator simplified models. Instead, GeV-scale photons in beam-dump environments can preferentially produce heavier KK gravitons whose profiles probe the intermediate brane, after which the excited modes cascade down the tower. If decays into radion-like states are kinematically closed for the terminal mode, the lightest accessible KK graviton can be long-lived and decay visibly into a pair of photons. This leads to a distinctive intensity-frontier signature: heavy-mode production, intratower showering, and macroscopic electromagnetic decays. We present the model ingredients, derive the relevant overlap-controlled couplings, characterize the generic production and decay phenomenology, and discuss the theoretical and precision constraints on this class of low-scale warped scenarios.
hep-ph0 citations
06
Probing Non-Holomorphic Modular $A_{4}$ Double Seesaw: Signatures in Neutrino Oscillation Experiments and Implications for Leptogenesis
Pratik Adarsh🇮🇳 · Dinesh Kumar Singha🇭🇷 · Mitesh Kumar Behera🇮🇳 · Sudhanwa Patra🇮🇳
We realize the double seesaw mechanism within a non-holomorphic modular $A_{4}$ framework by extending the Standard Model with three generations of right-handed neutrinos (RHNs), three left-handed sterile neutrino fields, and an $A_{4}$ -singlet scalar. The modular construction forbids a bare Majorana mass term for the RHNs and realizes the hierarchy required for the double seesaw, with RHN masses induced through the heavier sterile neutrino sector. A comprehensive scan of the modular parameter space yields viable normal ordering solutions consistent with current neutrino oscillation data. We further examine their testability at DUNE, T2HK, and JUNO. DUNE and T2HK strongly probe the atmospheric mixing parameters and constrain the allowed model space, while JUNO provides complementary precision sensitivity to the solar mixing angle and mass-squared splitting. The oscillation compatible points also determine the induced RHN spectrum and complex Yukawa textures relevant for thermal leptogenesis. For a representative unflavored benchmark in the strong-washout regime, numerical Boltzmann evolution including decays and inverse decays yields $Y_{Δ B} ≃ 8.11 \times 1 0^{- 11}$ , close to the observed baryon asymmetry. The allowed parameter space also admits an $N_{1}$ -dominated two-flavor thermal leptogenesis realization with a hierarchical, non-resonant RHN spectrum. Our results establish the non-holomorphic modular $A_{4}$ double seesaw as a predictive framework linking low-energy neutrino phenomenology and thermal leptogenesis, with oscillation predictions directly testable at forthcoming precision neutrino experiments.
hep-ph0 citations
07
A window for the mixed same-sign signature in the type-II seesaw models
Cheng-Wei Chiang🇹🇼
The mass splitting between the doubly and singly charged members of the Higgs triplet of the type-II seesaw model is usually treated as a free parameter in the collider literature. Electroweak loops fix it to $767$ to $841$ ~MeV over the mass range considered here once the quartic coupling $λ_{4}$ is set to zero at the renormalization scale $μ = M_{H^{\pm\pm}}$ . Moving that scale by a factor of two in either direction moves the loop value by $208$ ~MeV at $200$ ~GeV, falling to $42$ ~MeV at $1$ ~TeV. At the reference splitting of $852$ ~MeV, the transition $H^{\pm\pm} \to H^{\pm} W^{\pm (*)}$ takes $40%$ ( $7%$ ) of the total width at the crossover triplet vacuum expectation value for a doubly charged Higgs mass of $200$ ~GeV ( $500$ ~GeV). That splitting is also where the partonic counting of that rate fails. Evaluated from hadronic data, the counting overestimates the rate by a factor $1.46 \pm 0.05$ at a splitting of $852$ ~MeV and underestimates it by a factor $4.87 \pm 0.09$ at $200$ ~MeV. Whether the mixed same-sign topology survives is then a condition on $λ_{4}$ . The same channel moves the two published exclusion boundaries in opposite directions, by $- 1.4%$ and $+ 24.5%$ , at the level of branching ratios and at fixed experimental acceptance.
hep-phhep-ex0 citations
08
Dielectric Response for Light Dark Matter Direct Detection Beyond the Longitudinal Approximation
Zheng-Liang Liang🇨🇳 · Lei Wu🇨🇳 · Wen-Na Yang🇨🇳 · Lin Zhang🇨🇳 · Bin Zhu🇨🇳
The dielectric formalism for light dark matter--electron scattering in semiconductors has, to date, employed only the longitudinal dielectric function $ϵ_{L}$ , with the transverse response $ϵ_{T}$ universally neglected on qualitative grounds. A complete derivation and quantitative evaluation of $ϵ_{T}$ in this context has been lacking. We provide this derivation within the random phase approximation for a homogeneous electron gas. For silicon, we find that the transverse energy loss function is $4 - - 6$ orders of magnitude below the longitudinal one in the bulk plasmon regime, providing the first rigorous justification for the conventional longitudinal approximation. The sizable transverse corrections appear for deposited energies $ω ≲ 1 eV$ , which lies below the energy required to reliably produce one electron-hole pair in silicon detectors. Our results provide a quantitative error assessment for existing longitudinal calculations and identify kinematic regimes where transverse corrections ought to be included for relativistic dark-matter interpretations.
hep-ph0 citations
09
Qubits for Dark Matter Hunting
Takeo Moroi🇯🇵
An introductory review is provided for those who are interested in exploring applications of qubits and other quantum excitations to the detection of dark matter (and any other physics beyond the Standard Model). Topics covered include the fundamental properties of qubits, the excitation mechanism of qubits due to the electric field induced by dark matter (with attention to the effects of the coherence of dark matter), the dynamics of coupled qubit-cavity systems modeled by the Jaynes-Cummings framework, and the influence of noise and decoherence (especially Markovian noise described by the Lindblad equation). In addition, the article introduces essential concepts in quantum sensing, including the operator-sum representation and positive operator-valued measures, the Cramér-Rao bound, the standard quantum limit and the Heisenberg limit, and the potential enhancement of sensitivity to dark matter achievable with entangled states. Throughout, these topics are discussed with particular emphasis on their application to the detection of wave-like dark matter.
hep-phastro-ph.COhep-exquant-ph0 citations
10
Anomaly-free axion-like particle in Nelson-Barr models
Mohammad Aghaie🇯🇵 · Ryoma Masuda🇯🇵 · Ryosuke Sato🇯🇵
We study Nelson--Barr models with a discrete $Z_{N}$ symmetry that solve the strong CP problem through spontaneous CP violation, and show that they naturally predict a light axion-like particle (ALP) without introducing any additional ingredients. Unlike the QCD axion, this ALP is anomaly-free: its couplings to photons and gluons are highly suppressed, rendering it naturally long-lived. Instead, it couples to quarks through flavor-violating interactions whose structure is dictated by the CKM matrix. These interactions induce rare meson decays, providing a unique probe of the Nelson--Barr mechanism. We study the cosmological production of the ALP through both freeze-in and misalignment mechanisms. We show that the parameter space in which the observed relic abundance is explained by the freeze-in mechanism is subject to stringent constraints from precision flavor experiments and stellar cooling bounds from SN1987A, leaving only a small viable region that will be comprehensively tested by future structure-formation observations such as the Vera Rubin Observatory and next-generation X-ray missions like Athena, GECCO and THESEUS. In contrast, misalignment production remains a robust and viable mechanism for explaining the observed dark matter abundance over a broad region of parameter space. Our results demonstrate that precision flavor measurements, cosmological observations, and X-ray searches provide complementary probes of this anomaly-free ALP and, consequently, of the Nelson--Barr solution to the strong CP problem.
hep-ph0 citations
11
The role of triangle singularity in the $B^{0} \to D^{-} π^{+} a_{0} (980) (π^{0} η)$ decay
Wei Wang🇨🇳 · Dazhuang He🇨🇳 · Xuan Luo🇨🇳
The triangle singularity interpretation of the \replyhe{ $a_{1} (1420)$ } observed by the COMPASS Collaboration has been widely accepted. In this work, we investigate the triangle mechanism in the decay $B^{0} \to D^{-} π^{+} a_{0} (980) (π^{0} η)$ , where the $a_{0} (980)$ is treated as a dynamically generated state. The $K ˉ^{* 0}$ - $K^{+}$ - $K^{-}$ triangle loop originates from the decay $B^{0} \to D^{-} K^{+} K ˉ^{* 0}$ , which has been observed by the Belle Collaboration, followed by the subsequent decay $K ˉ^{* 0} \to K^{-} π^{+}$ . The triangle amplitude develops a pronounced peak around 1420 MeV, which is reflected in the invariant mass spectrum of the $π a_{0} (980)$ system. The differential decay width is calculated and exhibits a narrow peak around $980 MeV$ in the $π^{0} η$ invariant mass distribution. Furthermore, the invariant mass distribution of the $π^{+} π^{0} η$ system shows a clear peak around $1420 MeV$ , which further \replyhe{confirms} the triangle singularity explanation of the \replyhe{ $a_{1} (1420)$ }. We expect that the proposed $B^{0}$ decay mode could provide a potential platform for further exploring the triangle-singularity nature of the \replyhe{ $a_{1} (1420)$ } and could be tested in future experiments such as LHCb, BESIII, and Belle~II.
hep-ph0 citations
12
The excited baryon spectrum from a unified quark model
Yan-Ke Chen🇨🇳 · Liang-Zhen Wen🇨🇳 · Wei-Lin Wu🇨🇳 · Lu Meng🇨🇳 · Shi-Lin Zhu🇨🇳
A common approach to studying the multiquark states is to solve the few-body Schrödinger equation within a quark potential model. The multiquark states may contain quarks with several different flavors and have richer color structures than ordinary hadrons. The reliability of such an investigation requires that the underlying quark potential model can simultaneously describe the meson and baryon spectra across all flavor sectors, including orbital and radial excitations, with a single parameter set. At present, no quark potential model fully satisfies this requirement. We construct a simple nonrelativistic constituent quark potential model that includes spin--orbit and tensor interactions. We refit the model parameters to the latest experimental data. The excited light hadrons and several exotic hadron candidates are excluded from the fit. The resulting parameter set reproduces the spectra across all fitted sectors. The vast majority of deviations are below 20 MeV, while the largest deviations remain of the order of several tens of MeV, which is the typical accuracy of nonrelativistic quark potential models. Using the same parameters, we predict the spectra and internal structures of the orbitally and radially excited heavy baryons, which await further experimental determination. The excited light baryons are calculated with the same parameters. The calculated excited light baryon spectra deviate substantially from experimental values. Our refitted model does not resolve these longstanding discrepancies. The results delimit the range of validity of the nonrelativistic constituent quark potential model. By treating mesons and baryons across all flavor sectors, including both orbital and radial excitations within a unified framework, the model provides a controlled starting point for few-body calculations of multiquark states. We also urge experimental searches for the predicted states.
hep-phhep-exhep-lat0 citations
13
The ABC of RPV III: Classification of R-parity Violating Signatures from LQD Couplings and their Coverage at the LHC
Herbi K. Dreiner🇩🇪 · Yong Sheng Koay🇸🇪 · Tina Potter🇬🇧 · Martin Schürmann🇩🇪 · Rhitaja Sengupta🇩🇪 · Apoorva Shah🇩🇪 · Nadja Strobbe🇺🇸
We consider the R-parity violating Minimal Supersymmetric Standard Model (RPV-MSSM) with its wide range of signatures as a test model for the coverage of beyond the Standard Model searches at the LHC. Here we present a systematic study of the phenomenological and experimental status of specifically the R-parity violating $L Q D ˉ$ operators, as the third study in the ABC of RPV series, following our previous analyses of the $LL E ˉ$ and $U ˉ D ˉ D ˉ$ operators. We classify the distinct collider signatures for all possible LSPs and for eight representative $L Q D ˉ$ couplings, considering both direct LSP production and production through gauge cascades. Assuming one non-zero $L Q D ˉ$ coupling at a time, we assess the current LHC coverage using ATLAS and CMS searches implemented in $CheckMATE 2$ , and identify recent searches relevant for future recasting. We find substantial sensitivity to the colored sector, while gaps remain for wino- and higgsino-like LSPs for couplings involving $τ$ leptons, when the LSP is the only sparticle within the LHC kinematic limit. Slepton LSPs remain unconstrained in their direct production at the LHC, although some sensitivity is found for slepton NLSPs with a bino-like LSP. These results highlight gaps in the $CheckMATE 2$ search database, as well as the need for targeted LHC searches for specific $L Q D ˉ$ signatures.
hep-phhep-ex0 citations
14
Unraveling QCD dynamics with heavy quark energy correlators
Ivan Vitev🇺🇸
Heavy-flavor jets and their substructure provide a unique window into the role of quark mass on QCD radiation and its modification in nuclear matter. In this work, we investigate heavy-quark energy-energy correlators (EECs) that are explicitly sensitive to mass effects, focusing on angular distributions, energy flow, and the dead-cone effect. We demonstrate how the finite mass of charm and bottom quarks reshapes the intra-jet radiation pattern, leading to characteristic suppression at small angles and measurable deviations from massless jet expectations. Using effective field theory analysis, we extend the calculation of these observables to reactions with nuclei to show that medium-induced radiation competes with vacuum mass suppression, resulting in a nontrivial modification of jet substructure. Specifically, we identify regimes where EECs are dominated by the heavy quark mass, leading to qualitatively and quantitatively different behavior of this observable in QCD matter. We discuss the charm and bottom jet energy-energy correlators modification in reactions with nuclei, and further demonstrate how the formalism can be tested in small collision system at current facilities.
hep-phnucl-th0 citations
15
The electron parton distribution functions at the NNLO in QED
Stefano Frixione🇮🇹 · Kay Schönwald🇨🇭
The electron Parton Distribution Functions (PDFs) are essential components in the calculations of cross sections within a collinear-factorisation framework at lepton colliders. We compute them at the next-to-next-to-leading order (NNLO) in QED by working in two different factorisation schemes, namely the standard $MS$ one and the so-called $Δ$ scheme, which was originally defined at the next-to-leading order, and which we generalise in this work by extending its definition to all orders. We present analytical results relevant to the large- $z$ behaviour of the PDFs in both factorisation schemes, and thus show how the soft-logarithm enhancement of the $MS$ electron PDF is completely absent in the $Δ$ scheme. The latter therefore constitutes a natural choice that helps significantly reduce the complexity not only of numerical simulations in phenomenological applications, but also that of analytical computations necessary to achieve the soft resummation of physical observables. We argue that NNLO PDFs are necessary to attain relative-precision targets of $1 0^{- 4}$ or better, for colliders whose centre-of-mass energies are in the hundred-GeV range.
hep-ph0 citations
16
Higgs Boson plus Quark Pair Production at High Energies as di-Higgs Background
Andreas Maier🇵🇱 · Giacomo Ruisi🇩🇪
We investigate the impact of high-energy QCD resummation on Higgs-boson production processes relevant for Higgs-pair studies at the Large Hadron Collider. We present the first dedicated study of Higgs boson production in association with a bottom-quark pair and two additional hard jets in the gluon-fusion channel at high energies as a background to vector-boson-fusion Higgs-pair production. The resummation can significantly modify the QCD contribution in VBF-like regions of phase space, indicating that fixed-order calculations overestimate the contamination from gluon-fusion backgrounds. We then extend existing High Energy Jets (HEJ) predictions for Higgs boson production in association with jets by including quark-pair resummation effects for the first time.
hep-ph0 citations
17
Implications of two-channel rescattering for charm CP violation from precise dispersive data
Antonio Pich🇪🇸 · Eleftheria Solomonidi🇨🇭 · Luiz Vale Silva🇪🇸
The experimental observation of large CP violation in charm-meson hadronic decays remains theoretically unexplained within the Standard Model. The data-driven approach which accounts for the rescattering between the final-state pion and kaon pairs provides predictions that fall short of the experimental values. However, it relies on a set of inputs that exhibit large uncertainties. In this work, we make optimal use of the available information on branching ratios and of only one strong-scattering input parameter that is well determined. We find that it remains unlikely to explain the experimental signal within this approach and obtain predictions for sum rules that constrain CP asymmetries of the pion and kaon channels.
hep-phhep-ex0 citations
18
Efficient Event Generation for High-Multiplicity LHC Processes: An End-to-End GPU Workflow with Normalizing Flows
Enrico Bothmann🇨🇭 · Joshua Isaacson🇺🇸 · Claudius Krause🇦🇹 · Carla J. López-Zurita · Maximilian Spannring · Daohan Wang🇦🇹
Producing very large unweighted event samples for high-multiplicity processes is limited by expensive matrix-element evaluations and low unweighting efficiencies. We present the first end-to-end GPU-resident event-generation workflow that integrates normalizing-flow proposals with the parton-level event generator Pepper. Helicity-conditioned coupling flows are trained using online updates supplemented by sample replay and deployed across all subprocesses of complete proton--proton collision processes with many final-state jets. In this workflow, a Python-based control layer and Pepper exchange flow-generated phase-space points and the corresponding target-density evaluations directly in device memory. The control layer performs flow sampling, proposal-density evaluation, and unweighting, while Pepper evaluates the matrix elements, PDFs, and phase-space factors defining the target density and writes the accepted events in standard formats. We compare subprocess-specific flows, with one flow per partonic subprocess, to grouped conditional flows that share parameters among subprocesses with related parton content. The workflow is benchmarked for $pp \to e^{+} e^{-} + 4 j$ , $pp \to e^{+} e^{-} + 5 j$ , $pp \to t t ˉ + 4 j$ , $pp \to 4 j$ , and $pp \to 5 j$ production. On four H100 GPUs, we generate $1 0^{9}$ unweighted events for each benchmark process. Including the cost of flow training, the workflow achieves end-to-end speedups of up to two orders of magnitude over standalone Pepper event generation and turns a multi-week task into a sub-day computation. It thereby makes billion-event production more practical and offers a pathway to alleviating the Monte Carlo statistics bottleneck in high-multiplicity collider physics.
hep-phhep-ex1 citation
19
The friction-era VOS amplitude of a $Z_{2}$ string network from nematic disclination data
Dimitrios Efstratiou🇬🇷 · Evangelos Achilleas Paraskevas🇬🇷 · Leandros Perivolaropoulos🇬🇷
A tangle of line defects coarsens as the mean spacing $L$ between neighbouring lines grows. In a viscous medium the motion is overdamped, and the velocity-dependent one-scale (VOS) model predicts a late-time attractor $L^{2} = A ℓ_{d} t$ , with $ℓ_{d} = T /Γ$ the ratio of line tension to drag and $A$ a dimensionless amplitude. The growth law $L \propto t^{1/2}$ holds for every value of the three model parameters---the momentum parameter $k \leq 1$ , the sink coefficient $c ~$ , and the curvature ratio $λ \equiv R / L$ ---since all three enter only through $A = κ (κ + c ~)$ , $κ \equiv k / λ$ . Thus, the exponent constrains none of them, and the amplitude is the only quantity a density history can deliver. We measure it from the disclination data of Chuang, Turok and Yurke on a nematic liquid crystal, whose companion measurement of loop collapse fixes $ℓ_{d}$ on the same samples, canceling the 5CB material constants. Treating the unmatched per-quench $ℓ_{d}$ as a nuisance parameter with a Gaussian prior and marginalizing it analytically, we obtain $A = 10. 0_{- 1.1}^{+ 1.3}$ from the three quenches in the $234 μ$ m cell; the fourth, the only one in the thinner $158 μ$ m cell, gives $A = 3. 0_{- 0.6}^{+ 0.8}$ and is fitted separately. Converting either into $c ~$ requires $λ$ , which these data do not determine, so the result is a curve, $c ~ (λ) = A λ / k - k / λ$ , not a number. At $λ = 1$ with $k \leq 1$ they give $c ~ \geq 9.0$ and $c ~ \geq 2.0$ , against $c ~ = 0.23$ -- $0.57$ from relativistic $U (1)$ simulations, values reached only at $λ ≃ 0.33$ -- $0.35$ and $0.62$ -- $0.68$ . We know of no VOS calibration for a cosmological $Z_{2}$ network, so we cannot attribute the excess to topology, and we list what a repeat experiment must measure.
↳ cond-mat.softhep-phhep-th0 citations
20
One-point matter PDFs beyond TopHat filters
Anton Chudaykin🇨🇭 · Alexander M. Kayssi · Sergey Sibiryakov🇨🇦
We study the one-point probability distribution function (PDF) for matter densities averaged with an arbitrary spherically symmetric window function. The PDF is analytically modeled within the path integral framework, enabling a non-perturbative description of large-scale structure. It contains a leading order contribution controlled by the spherically symmetric gravitational collapse dynamics, as well as an order-one factor arising from aspherical fluctuations. We develop a numerical pipeline to compute the leading spherical-collapse part of the PDF and apply it to a family of window functions interpolating between the TopHat and Gaussian filters in coordinate space, as well as to a window function with non-monotonic radial dependence. We find that the PDF weakly depends on the choice of the filter, provided the width of the filter is normalized to yield a fixed linear averaged density variance. For each filter and each value of the averaged density, our pipeline gives the most probable density profile. We find that these profiles vastly differ for different filters in the case of overdensities, but closely follow a universal curve at underdensities. We obtain a perturbative expression for the aspherical part of the PDF valid at small density contrasts. We find from it that all PDFs are equally sensitive to the effective field theory (EFT) corrections accounting for short-scale clustering, regardless of how smooth the filter's boundary is. We test our PDF model against the results of high-resolution N-body simulations. The agreement is excellent for filters with widths larger than 10 Mpc/h. Small discrepancies at a few percent level arise for narrower filters and are interpreted as higher-order perturbative corrections.
↳ astro-ph.COhep-phhep-th0 citations
21
CDRL: Certification-Driven Reinforcement Learning for Neutrino Flavor Model Discovery
Piyush Jha🇺🇸 · Jake Rudolph🇺🇸 · Victoria Knapp-Pérez🇺🇸 · Max Fieg🇺🇸 · Aishik Ghosh🇺🇸 · Vijay Ganesh🇺🇸
Many scientific discovery problems require searching combinatorial hypothesis spaces under complex domain constraints. Reinforcement learning (RL) offers a promising approach, but existing methods rely on scalar rewards that provide limited information about why candidate solutions fail, leading agents to repeatedly explore invalid regions. We introduce Certification-Driven Reinforcement Learning (CDRL), a framework that leverages structured feedback from symbolic reasoning tools. When a candidate violates domain constraints, these tools produce certificates identifying the actions responsible for failure. CDRL converts these certificates into reusable constraints that eliminate classes of invalid solutions and guide exploration toward valid regions. We evaluate CDRL on neutrino flavor model discovery in theoretical particle physics, where the hypothesis space exceeds $1 0^{26}$ possible models, and compare it with the state-of-the-art RL approach previously used for this task. Across three theory spaces, CDRL achieves up to 1.95 $\times$ higher valid model rates and up to 6.33 $\times$ higher neutrino model rates while evaluating up to 4 $\times$ fewer candidates. We further extract 40 interpretable rules from search trajectories using a post-hoc decision-tree framework and show that reusing them as soft constraints yields gains of up to 2 $\times$ in valid model rates and 3 $\times$ in neutrino model discovery across all three theory spaces. These results suggest that CDRL uncovers reusable structure in combinatorial search spaces and provides a general framework for scientific model discovery.
↳ cs.AIcs.LGcs.LOhep-ph0 citations
22
Hyperonic compact stars with vector portal dark matter
Prafulla K. Panda🇮🇳 · Deepak Kumar🇮🇳 · Hiranmaya Mishra🇮🇳 · Sudhanwa Patra🇮🇳
The appearance of hyperons in the core of neutron stars generally softens the equation of state (EOS), posing a longstanding challenge to the existence of observed two-solar-mass compact stars. We investigate whether repulsive interactions mediated by a dark-sector vector portal can provide an additional source of high-density pressure and thereby modify the structure of hyperonic compact stars. The baryonic sector is described within the modified quark-meson coupling (MQMC) model, in which the octet baryons are treated as confined relativistic constituent-quark systems interacting self-consistently through the $σ$ , $ω$ , and $ρ$ fields within a mean field approximation. The dark sector consists of a fermionic dark matter coupled to baryonic matter through a neutral vector mediator $Z^{'}$ , generating an additional repulsive contribution to the dense-matter EOS. We investigate the resulting equation of state, mass--radius relation, tidal deformability, and moment of inertia. The resulting mass--radius relations satisfy the observational bounds from massive pulsars, including PSR J0740 + 6620, with maximum neutron star masses reaching approximately $2 M_{⊙}$ . The resulting changes in tidal and rotational observables provide additional avenues for testing the dark-sector interaction through multimessenger observations.
↳ astro-ph.HEhep-phnucl-th0 citations
23
Quantum Horizon Tadpole and Emergence of a de Sitter Interior
Chong-Sun Chu🇹🇼
In a recent paper \cite{Chu:2026dhx}, the quantum stability of the fuzzy sphere was established at large but finite $N$ . In addition, a tadpole was identified for the scaling fluctuation mode of the matrix geometry. In this paper, we show that the tadpole generates a positive surface tension and tends to contract the sphere if the horizon is left isolated. However, when the horizon is coupled to gravity, the tadpole requires the bulk geometry to adjust according to the junction condition of general relativity. Assuming a static, spherically symmetric and non-singular vacuum interior, pure de Sitter space is selected. The matching also fixes an intriguing large- $N$ soldering relation between the de Sitter time inside and the Schwarzschild time outside. Potential cosmological implications are discussed.
↳ hep-thgr-qchep-ph0 citations
24
Exponential-in- $N_{c}^{2}$ cost reduction of product-formula-based quantum simulations of quantum chromodynamics
Zohreh Davoudi🇺🇸 · Jesse R. Stryker🇺🇸
Quantum algorithms for simulating quantum chromodynamics (QCD) have matured steadily since the pioneering work of Byrnes and Yamamoto [PRA 73, 022328 (2006)]. The most popular strategies for Hamiltonian simulation involve product-formula decompositions. However, the application of product-formula methods to SU( $N_{c}$ ) lattice gauge theories by Byrnes and Yamamoto leads to $O (Λ^{8 (N_{c}^{2} - 1)})$ gate complexity per Trotter step, where $Λ$ is the bosonic cutoff in the electric (i.e., irreducible-representation) basis. A seminal work by Kan and Nam [arXiv:2107.12769 (2021)] significantly improves over such an undesirable cost and reports an $O (Λ polylog (Λ))$ scaling, yet it still calls for an unrealistically large number of quantum gates. Here, we illuminate one of the reasons behind this high cost estimate and show that a factor of size $O (2^{4 (N_{c}^{2} - 1)})$ can be removed from the per-Trotter-step cost estimate by Kan and Nam. We specifically show that, by using methods developed in our past works [PRD 112, 014508 (2025); Quantum 7, 1213 (2023)], exponentiated-Hamiltonian decomposition---a necessary step in the application of product-formula algorithms---can be performed far more efficiently than previously thought. Our method reduces the T-gate cost estimate of QCD simulations using a second-order product formula by a factor of nearly $1 0^{14}$ , independent of simulation parameters and sizes. Focusing on simulations in the electric basis, we further contrast our results with other methods: the local-multiplet basis approach of Ciavarella, Klco, and Savage [PRD 103, 094501 (2021)] and the near-optimal algorithm of Rhodes, Kreshchuk, and Pathak [PRX Quantum 5, 040347 (2024)]. This work highlights the importance of continued algorithmic improvement to bringing the quantum-simulation cost of QCD within reach of realistic quantum computers.
↳ hep-lathep-phnucl-thquant-ph1 citation
25
Generation of TeV Photons by PeV Neutrinos in Dense Astrophysical Environments
Jun-Chen Wang🇨🇳 · Hanlin Song🇨🇳 · Hao Li🇨🇳 · Jie Zhu🇨🇳 · Bo-Qiang Ma🇨🇳
Recent observations by IceCube and KM3Net of PeV-scale ultra-high-energy (UHE) neutrinos, together with detections of TeV-PeV photons from various sources such as the Crab Nebula, the Galactic Center, and gamma-ray burst by ground-based observatories including Tibet AS $γ$ , MAGIC, Carpet-3, and LHAASO, point to the existence of extreme astrophysical environments capable of accelerating particles to ultra-high energies. These findings motivate investigations of possible connections between UHE neutrinos and photons in such environments. Theoretically, dense regions surrounding compact objects can efficiently produce UHE neutrinos. In this work, we calculate the production of UHE photons from neutrino-nucleon interactions, and note that if these interactions occur in the outer, optically thin regions of dense environments, the resulting photons could potentially be observed. In our model, an incident neutrino scatters off a nucleon, generating secondary partons that hadronize into pions and subsequently decay into UHE photons. We calculate the resulting photon energy spectra and find that for incident (anti)neutrinos with energies above 1 PeV, the probability of producing photons with energies exceeding 1 TeV is greater than 13%. As a concrete application, we show that this mechanism can quantitatively account for the preburst TeV photons observed in GRB 221009A, providing a natural explanation for both their energies and lead times. These findings establish a plausible mechanism linking UHE neutrino events to gamma-ray observations, providing new insights into hadronic processes in extreme astrophysical environments and supporting multi-messenger astronomy studies.
↳ astro-ph.HEhep-ph1 citation
26
Diversity of Galaxy Centers from Small-Scale Isocurvature
Jessica N. Lopez-Sanchez🇨🇿 · Wen Yin🇯🇵
The observed diversity of galaxy centers motivates the possibility that the local dark matter composition may vary among galaxies. In conventional multicomponent dark matter scenarios, however, large stochastic variations in the relative abundances are not generically expected, with the cold component typically remaining dominant. We perform $N$ -body simulations with a subdominant ultralight dark matter component carrying significant large-amplitude small-scale isocurvature perturbations. We find that although nonlinear evolution largely homogenizes its fraction on galactic scales,ultralight dark matter can still be enhanced and even dominate the centers of small halos because large initial ultralight dark matter fluctuations seed early potential wells that later form halo centers. The ultralight-dominated region can extend beyond $0.01 R_{vir}$ and account for more than half of the central dark matter density, even for a cosmological ultralight dark matter fraction below $O (10%)$ . This central segregation provides a possible route to stochastic cusp--core diversity, potentially explaining the observed diversity of galaxy centers.
↳ astro-ph.COgr-qchep-ph0 citations
27
High-Energy Neutrino Constraints on memory burdened Bardeen and Kerr Primordial Black Holes
Md Riajul Haque🇨🇳 · Suvashis Maity🇮🇳
The quantum memory burden effect can suppress the late-time Hawking evaporation of primordial black holes (PBHs), allowing PBHs below the standard evaporation threshold of approximately $1 0^{15} g$ to survive until the present epoch and potentially contribute to the dark matter abundance. We investigate primary and secondary neutrino emission from memory burdened Bardeen and Kerr PBHs, including Galactic and extragalactic fluxes and the effects of memory suppression, Bardeen regularization, and Kerr rotation. We constrain their abundance using observations from IceCube, Super-Kamiokande, and ANTARES, together with the projected sensitivities of IceCube-Gen2, GRAND200k, and Hyper-Kamiokande. We find that Bardeen regularization and Kerr rotation produce qualitatively different effects. Increasing the Bardeen parameter suppresses the Hawking temperature and neutrino flux, thereby weakening the abundance constraints. In contrast, rapidly rotating Kerr PBHs that retain a significant residual spin at the onset of the memory burdened phase can exhibit enhanced neutrino emission and substantially stronger constraints. Increasing the memory burden suppression index $k$ reduces the flux normalization but also allows lighter and hotter PBHs to survive, shifting the relevant signal toward higher energies. Consequently, HESE provides the leading sensitivity for weak suppression, whereas IceCube-Gen2 and GRAND200k become particularly important for stronger suppression. These results demonstrate the complementarity of current and future neutrino observations in probing memory burdened PBHs and the effects of regular geometry and rotation on their evaporation.
↳ astro-ph.COhep-ph0 citations
28
Classical versus non-classical photon states for detecting vacuum non-linearity
N. Ahmadiniaz🇩🇪 · C. Kohlfürst🇩🇪 · R. Shaisultanov🇨🇿 · R. Schützhold🇩🇪
Quantum electrodynamics (QED) predicts that the vacuum should behave as a non-linear medium. For many schemes aimed at verifying this fundamental prediction, the signal consists of one or more photons in a certain mode (determined by polarization $σ$ and wave-number $k$ ) which would be empty in the absence of a QED vacuum non-linearity. Here we consider modifying these schemes by sending in a classical or non-classical (e.g., squeezed) photon state instead of the initial vacuum state in that mode. We find that the detectability can be improved significantly.
↳ quant-phhep-ph0 citations

Affiliations

first authorsco-authorsvia INSPIRE