Thu·Jun 5, 2025Thursday·June 5, 2025

1. 01*

   Local-equilibrium theory of neutrino oscillations

   Lucas Johns🇺🇸 · Anson Kost🇺🇸

   Miscidynamics describes coarse-grained neutrino transport under the assumption that flavor mixing is in local equilibrium. Here we introduce the concept of turbulent flavor-wave viscosity and develop techniques for including it in miscidynamics. This extension of the theory is necessary when neutrinos develop weak flavor instabilities as a result of astrophysical driving. The flavor-wave dispersion relation is obtained using a new and more general form of linear analysis, which does not require small flavor coherence. Flavor-wave transport is then approximated using wave kinetics and geometric optics. We hypothesize that the dynamical emergence of local oscillation invariants restricts the extent of flavor thermalization. In this view, flavor evolution is sculpted by both entropy-increasing and order-promoting factors.

   hep-phastro-ph.HE18 citations
2. 02*

   Stringent Constraints on New Pseudoscalar & Vector Bosons from Precision Hyperfine Splitting Measurements

   Cedric de Jonge · Fabian Heiße🇩🇪 · Joerg Jaeckel🇩🇪 · Lutz Leimenstoll🇩🇪 · Christoph H. Keitel🇩🇪 · Zoltán Harman🇩🇪

   Axion-like particles and similar new pseudoscalar as well as vector bosons coupled to nucleons and electrons are predicted to lead to spin-dependent forces in atoms and ions. We argue that hyperfine structure measurements in hydrogen- and lithium-like charge states are a sensitive probe to this effect. Employing specific differences of these splittings reduces uncertainties due to nuclear effects in hyperfine structure calculations and measurements. Using this, we show that existing measurements on Be provide competitive limits in the region $m_{\varphi }\gtrsim 100\mathrm{keV}$, confirming, or improving by up to a factor of 2, existing constraints for pseudoscalar couplings, depending on the nuclear model. We also find that future measurements on Cs have a further factor of $2-2.5$ improved discovery potential for pseudoscalars and an order of magnitude for new vector bosons when compared with the corresponding current constraints.

   hep-phPRL(2026)·4 citations
3. 03*

   Revisiting Isocurvature Bounds on the Minimal QCD Axion

   Peter W. Graham🇺🇸 · Davide Racco🇺🇸

   The QCD axion has important connections to early universe cosmology. For example, it is often said that isocurvature limits rule out a combination of high axion decay constant, $f_a$, and high inflationary Hubble scale, $H_I$. High scales are theoretically motivated, so it is important to ask how robust this constraint is. We demonstrate that this constraint is naturally evaded when the quartic coupling of the complex $U(1{)}_{\mathrm{PQ}}$-breaking field is small. In this case, $f_a$ changes from a larger value during inflation to a smaller value in the later universe, suppressing isocurvature perturbations. Importantly, we show that in large parts of parameter space this solution is not jeopardised by overproduction of the axion through parametric resonance. The isocurvature bounds are thus dependent on UV physics. We have found that, even for the minimal QCD axion, large parts of UV parameter space at both high $f_a$ and high $H_I$ are in fact allowed, not ruled out by isocurvature constraints.

   hep-phastro-ph.COJHEP(2025)·22 citations
4. 04*

   Physics-Informed Neural Network Approach to Quark-Antiquark Color Flux Tube

   Wei Kou🇨🇳 · Xiaoxuan Lin🇨🇳 · Bing'ang Guo🇨🇳 · Xurong Chen🇨🇳

   We introduce a physics-informed neural network (PINNs) framework for modelling the spatial distribution of chromodynamic fields induced by quark-antiquark pairs, based on lattice Monte Carlo simulations. In contrast to conventional neural networks, PINNs incorporate physical laws-expressed here as differential equations governing type-II superconductivity-directly into the training objective. By embedding these equations into the loss function, we guide the network to learn physically consistent solutions. Adopting an inverse problem approach, we extract the parameters of the superconducting equations from lattice QCD data and subsequently solve them. To accommodate physical boundary conditions, we recast the system into an integro-differential form and extend the analysis within the fractional PINNs framework. The accuracy of the reconstructed field distribution is assessed via relative $L_2$-error norms. We further extract physical observables such as the string tension and the mean width of the flux tube, offering quantitative insight into the confinement mechanism. This method enables the reconstruction of colour field profiles as functions of quark-antiquark separation without recourse to predefined parametric models. Our results illuminate aspects of the dual Meissner effect and highlight the promise of data-driven strategies in addressing non-perturbative challenges in quantum chromodynamics.

   hep-phhep-thPRD(2025)·6 citations
5. 05*

   Imaginary Rotating Gluonic Matter at Strong Coupling

   Kenji Fukushima🇯🇵 · Yusuke Shimada🇯🇵

   We write down an effective theory of the Polyakov loop to investigate the deconfinement phase transition of imaginary-rotating gluonic matter using the strong-coupling expansion. We find the strength of the nearest-neighbor Polyakov-loop interaction modified by the sum of contributions involving the chair-type loops along the temporal direction. Our results show that the deconfinement transition temperature increases with increasing imaginary angular velocity, which agrees with the predictions from the models and the high-temperature perturbative calculations.

   hep-phhep-lathep-thPLB(2025)·13 citations
6. 06*

   Off-shell ambiguities in correlation functions: strategies to minimize them

   R. Molina🇪🇸 · E. Oset🇪🇸

   We face here the problem of uncertainties in correlation functions due to the freedom in the off-shell dependence of the wave functions, or equivalently, off-shell ambiguities in the scattering matrices. We make the study for the case of meson baryon interaction, choosing the $K\Lambda$, $K\Sigma$, $\eta N$ coupled channels, which are related to the $N^{\ast }(1535)$ resonance. We find that using realistic interactions based on chiral dynamics the uncertainties are small, of the order of $2-3$~\%, but could be much bigger if other methods are used. However, our study shows the way to optimally overcome these uncertainties in the analysis of correlation functions, and we provide a series of recommendations for any general analysis.

   hep-phnucl-thPRD(2025)·16 citations
7. 07*

   Influence of Photon Inverse Emission on Forward-Backward Asymmetry in Dilepton Production at the LHC

   Vladimir Zykunov🇷🇺

   The contribution of photon inverse emission to dilepton production in hadron collisions at the Large Hadron Collider (LHC) is calculated in detail. Numerical analysis of inverse emission effects on cross sections and forward-backward asymmetry is performed in a wide kinematic region covering the CMS experiment at the Run 3/HL-LHC regime, corresponding to ultra-high energies and high dilepton invariant masses. We apply an effective technique using additive relative corrections to analyse the impact of radiative contributions on forward-backward asymmetry.

   hep-ph0 citations
8. 08*

   Fermionic decay of light charged pseudoscalar in Georgi Machacek model

   Swagata Ghosh🇮🇳

   The Georgi Machacek (GM) model is a triplet extension of the scalar sector of the Standard Model (SM) containing charged and neutral scalars and pseudoscalars with alluring phenomenology. The CMS and ATLAS collaborations of the LHC at $\sqrt{s}=13$ TeV already searched for various decays of the charged Higgs boson in low as well as high mass region. The low mass charged Higgs are produced by the decay of top quarks or antiquarks. $H^{\pm }\to \tau \nu ,cs$ are the main fermionic decay channels of light charged scalars or pseudoscalars. For low mass region of the charged pseudoscalars, the triplet vev is restricted from above from the indirect search coming from the $b\to s\gamma$ decay. Here, I consider the observed data from the ATLAS and CMS both for the light charged Higgs decaying into $cs$ and $\tau \nu$. The ATLAS data observed for $H^{\pm }\to \tau \nu$ offers a more stringent bound on $v_2$ for GM model pseudoscalar mass below $160$ GeV.

   hep-phSpringer Proc.Phys.(2026)·1 citation
9. 09*

   Event Topology Classifiers at the Large Hadron Collider

   Suraj Prasad🇮🇳 · Sushanta Tripathy🇸🇪 · Bhagyarathi Sahoo🇮🇳 · Raghunath Sahoo🇮🇳

   Event classifiers are the most fundamental observables to probe the event topology of hadronic and nuclear collisions at relativistic energies. Over the last five decades, significant progress has been made to establish suitable event classifiers to probe different physics processes occurring in elementary $e^{+}{e}^{-}$ to heavy-ion collisions in a broad range of center of mass energies. One of the major motivations to revisit event classifiers at the Large Hadron Collider (LHC) originates from the recent measurements of high multiplicity proton-proton collisions, which have revealed that these small collision systems exhibit features similar to the formation of quark-gluon plasma (QGP), traditionally believed to be only achievable in heavy nucleus-nucleus collisions at ultra-relativistic energies. To pinpoint the origin of these QGP-like phenomena with substantially reduced autocorrelation and selection biases, and to bring all collision systems on equal footing, along with charged-particle multiplicity, lately several event topology classifiers such as transverse sphericity, transverse spherocity, relative transverse activity classifier, and charged-particle flattenicity have been used extensively in experiments as well as in the phenomenological front. In addition, the infrared and collinear safety of event-shape observables makes them ideal for precision studies of jets and heavy-flavors at the LHC. In this review article, we summarise the motivation, scope, and practical use of these event-shape observables. The discussion integrates results and insights from all major LHC experiments, setting the stage for precision investigations for Run 3, Run 4, and future high luminosity upgrades of the LHC.

   hep-phhep-exhep-thnucl-ex+1Phys.Rept.(2026)·17 citations
10. 10*

    Improved superscaling description of electron and charged-current neutrino quasielastic scattering using effective mass dynamics

    V.L. Martinez-Consentino🇪🇸 · P.R. Casale🇪🇸 · J.E. Amaro🇪🇸

    We present an improved version of the Superscaling Analysis with Relativistic Effective Mass, denoted as SuSAM-v2. In the original SuSAM model, a universal scaling function was fitted to a selected set of quasielastic electron scattering (e,e') cross section data, using a phenomenological ansatz inspired by the Relativistic Mean Field model of nuclear matter. In this work, we refine the procedure by first fitting a longitudinal scaling function directly to experimental longitudinal response data. Subsequently, a separate transverse scaling function is extracted from purely transverse data, after subtracting the longitudinal contribution already determined. We find that the resulting transverse scaling function must exhibit an explicit dependence on the momentum transfer q in order to reproduce all kinematics consistently. The resulting SuSAM-v2 model simultaneously describes inclusive quasielastic cross sections and both longitudinal and transverse response functions in electron scattering. The model is then applied to neutrino-nucleus scattering, showing an improved prediction compared to the previous SuSAM-v1 version, due to a more accurate treatment of the relative contributions of the longitudinal and transverse weak nuclear responses.

    hep-phnucl-thPRD(2025)·2 citations
11. 11*

    Dark matter mixing within the seesaw type II mechanism in the left-right symmetric model

    M. Dubinin🇷🇺 · E. Fedotova🇷🇺 · D. Kazarkin🇷🇺

    The seesaw type II mechanism is considered within the framework of a left-right chiral model with a gauge group $SU(2{)}_L\times SU(2{)}_R\times U(1)$, the lepton sector of which includes three generations of heavy Majorana neutrinos. The dependence of the mixing parameters of the lightest sterile neutrino as a dark matter particle on the scales of left-right symmetry breaking in the case of direct and inverse hierarchies of active neutrino masses is analyzed.

    hep-phPhys.Part.Nucl.Lett.(2025)·0 citations
12. 12*

    Heavy Neutral Lepton Decay Searches using Solar Neutrinos

    Patrick Huber🇺🇸 · Yulun Li🇺🇸

    We study the sensitivity to the decay of a heavy neutral lepton into $e^{+}{e}^{-}$-pairs using the solar boron-8 neutrino flux as source. We provide a fully differential cross section for this process including the interference of neutral and charged current amplitudes. We revisit a previous bound from Borexino and make predicitions for the expected sensitivity in future large liquid noble gas detectors, like XLZD, Argo and DUNE, as well as high-resolution scintillator detectors based on the LiquidO technology. We find that more than two orders of magnitude improvement in mixing angle reach is possible relative to existing bounds.

    hep-phPRD(2026)·0 citations
13. 13*

    Could an axion-like particle be hidden in ${\eta }_c\to \gamma \gamma$?

    Zhi-Jun Li🇨🇳 · Zheng-Yun You🇨🇳 · Xiao-Rui Lyu🇨🇳

    We discuss the possibility of an axion-like particle being merged in the recent observation of ${\eta }_c\to \gamma \gamma$ at BESIII and find that it cannot be excluded in the current experimental data. The mass, width, and coupling strengths of the axion-like particle are extracted, and several other channels to confirm or exclude the existence of such an axion-like particle are also discussed.

    hep-ph0 citations
14. 14*

    Hunting and identifying coloured resonances in four top events with machine learning

    Thomas Flacke🇰🇷 · Jeong Han Kim🇰🇷 · Manuel Kunkel🇩🇪 · Jun Seung Pi🇰🇷 · Werner Porod🇩🇪

    We study prospects to search for pair or singly produced colour octet or colour sextet scalars which decay into two top quarks at the LHC. We focus on the same-sign lepton final state. We train a neural network comprising a simple multilayer perceptron combined with a convolutional neural network to optimize the separation of signal and background events. For LHC operated at 14 TeV and a luminosity of 3 ab${}^{-1}$ we find an expected discovery reach of $m_8=1.8$ TeV and $m_6=1.92$ TeV for pair produced colour octets and sextets, respectively, and an expected exclusion reach of $m_8=2.02$ TeV and $m_6=2.14$ TeV. In a second step, we retrain the same network architecture to discriminate between signal processes. The network can clearly distinguish between the different colour representations. Moreover, we can also determine whether there is a significant contribution from single production to pair production for the same final state. The methodology can be applied to BSM candidates of different spin and colour representations.

    hep-phhep-exJHEP(2026)·7 citations
15. 15*

    {\tt ggxy}: a flexible library to compute gluon-induced cross sections

    Joshua Davies🇬🇧 · Kay Schönwald🇨🇭 · Matthias Steinhauser🇩🇪 · Daniel Stremmer🇩🇪

    We present the library {\tt ggxy}, written in {\tt C++}, which can be used to compute partonic and hadronic cross sections for gluon-induced processes with at least one closed heavy quark loop. It is based on analytic ingredients which avoids, to a large extent, expensive numerical integration. This results in significantly shorter run-times than other similar tools. Modifying input parameters, changing the renormalization scheme and varying renormalization and factorization scales is straightforward. In Version~1 of {\tt ggxy} we implement all routines which are needed to compute partonic and hadronic cross sections for Higgs boson pair production up to next-to-leading order in QCD. We provide flexible interfaces and allow the user to interact with the built-in amplitudes at various levels.

    hep-phhep-exComput.Phys.Commun.(2026)·21 citations
16. 16*

    Secluded Dark Composites and Remnant Binding Fields

    Katarina Bleau🇨🇦 · Yilda Boukhtouchen🇨🇦 · Joseph Bramante🇨🇦 · Rohan Kulkarni🇨🇦

    Dark matter may freeze-out and undergo composite assembly while decoupled from the Standard Model. In this secluded composite scenario, while individual dark matter particles may be too weakly-coupled to detect, the assembled composite can potentially be detected since its effective coupling scales with number of constituents. We examine models and observables for secluded composites, and in particular we investigate the cosmological abundance of the composite binding field, which is generated during freeze-out annihilation and secluded composite assembly. This binding field could be discovered as a new relativistic species in the early universe or through later interactions as a subdominant dark component.

    hep-phastro-ph.COhep-thJCAP(2025)·4 citations
17. 17*

    From Bjorken Scaling to Scaling Violations

    Giorgio Parisi🇮🇹

    This paper traces the historical and conceptual journey from Bjorken scaling to the discovery of scaling violations in deep inelastic scattering, culminating in the development of Quantum Chromodynamics (QCD). Beginning with the challenges faced by early strong interaction theories in the 1950s, we explore the emergence of agnostic approaches such as the bootstrap philosophy and current algebra, which sought to describe hadronic phenomena without relying on specific field theories. The pivotal role of experimental results from SLAC in the late 1960s is highlighted, leading to Bjorken's proposal of scaling in deep inelastic scattering and Feynman's parton model. We then delve into the theoretical breakthroughs of the 1970s, including Wilson's operator product expansion and the renormalization group, which provided the framework for understanding scaling violations. The discovery of asymptotic freedom in non-Abelian gauge theories by Gross, Wilczek, and Politzer marked a turning point, establishing QCD as the theory of strong interactions. Finally, we discuss the formulation of the Altarelli-Parisi equations, which elegantly describe the evolution of parton distribution functions and scaling violations, and their profound impact on the study of hard processes in particle physics. This paper not only recounts the key developments but also reflects on the interplay between theory and experiment that drove the field forward.

    ↳ physics.hist-phhep-phhep-thHiHEP(2025)·6 citations
18. 18*

    Physics and Computing Performance of the EggNet Tracking Pipeline

    Jay Chan🇺🇸 · Brandon Wang🇺🇸 · Paolo Calafiura🇺🇸

    Particle track reconstruction is traditionally computationally challenging due to the combinatorial nature of the tracking algorithms employed. Recent developments have focused on novel algorithms with graph neural networks (GNNs), which can improve scalability. While most of these GNN-based methods require an input graph to be constructed before performing message passing, a one-shot approach called EggNet that directly takes detector spacepoints as inputs and iteratively apply graph attention networks with an evolving graph structure has been proposed. The graphs are gradually updated to improve the edge efficiency and purity, thus providing a better model performance. In this work, we evaluate the physics and computing performance of the EggNet tracking pipeline on the full TrackML dataset. We also explore different techniques to reduce constraints on computation memory and computing time.

    ↳ physics.data-anhep-exhep-phEPJ Web Conf.(2025)·0 citations
19. 19*

    Vortices without inflow: bound spectra in horizonless rotational analogs

    H. S. Vieira🇩🇪 · Kyriakos Destounis🇵🇹

    Analog gravity experiments are making remarkable strides in unveiling both the classical and quantum nature of black holes. By harnessing diverse states of matter, contemporary tabletop setups now replicate strong-field phenomena typically confined to the enigmatic regions surrounding black holes. Through these modern gravity simulators, physical processes once considered elusive may finally be brought into experimental reach. In this work, we investigate the spectrum of massless scalar excitations propagating within the effective geometry of a rotating acoustic metric. Specifically, we build an analog vortex-like spacetime endowed with a tunable parameter that emulates the geometry of a rotating gravitational background. This model accommodates both the presence of a sonic horizon, characteristic of an acoustic black hole for non-zero tuning parameters, and its absence when the parameter vanishes, yielding a horizonless, purely rotational vortex flow devoid of radial inflow. We focus on the case where the vortex flow is purely rotational. The resulting spectral properties is found to be qualitatively consistent with that observed in recent experimental realizations of giant multiply quantum vortices featuring solid or hollow cores. This correspondence suggests that the analog spacetime used here holds significant potential to replicate, qualitatively, the phenomenology of cutting-edge laboratory experiments. In doing so, it offers new insight into the intricate landscape of analog black-hole spectroscopy and, potentially, the resonant topography of bounded, rotating astrophysical environments around black holes.

    ↳ gr-qcastro-ph.GAhep-phhep-thPRD(2025)·6 citations
20. 20*

    Insights in $f(Q)$ cosmology: the relevance of the connection

    Ismael Ayuso🇪🇸 · Mariam Bouhmadi-López🇪🇸 · Che-Yu Chen🇯🇵 · Xiao Yan Chew🇨🇳 · Konstantinos Dialektopoulos🇷🇴 · Yen Chin Ong🇨🇳

    We explore the role of the affine connection in $f(Q)$ gravity, a modified theory where gravity is governed by non-metricity within the symmetric teleparallel framework. Although the connection is constrained to be flat and torsionless, it is not uniquely determined by the metric, allowing for multiple physically distinct formulations. We analyze three such connections compatible with a homogeneous and isotropic universe to show that they yield markedly different cosmological dynamics, even under the same functional form of $f(Q)$. Using both analytical and numerical methods, including a Born-Infeld type model of $f(Q)$, we demonstrate that specific connections can resolve cosmological singularities like the Big Bang and Big Rip, replacing them with smooth de Sitter phases. Others retain singularities but with notable modifications in their behavior. These findings highlight the physical relevance of connection choice in $f(Q)$ gravity and its potential to address fundamental cosmological questions.

    ↳ gr-qcastro-ph.COhep-phhep-thJCAP(2025)·24 citations
21. 21*

    Electron-antineutrino spectrum from precision measurements of ${}^{144}$Pr-decay

    A.V. Derbin🇷🇺 · I.S. Drachnev🇷🇺 · D.V. Ivanov🇷🇺 · I.M. Kotina🇷🇺 · V.N. Muratova🇷🇺 · N.V. Niyazova🇷🇺 · D.A. Semenov🇷🇺 · M.V. Trushin🇷🇺 · E.V. Unzhakov🇷🇺

    The ${}^{144}$Ce -- ${}^{144}$Pr electron antineutrino source is one of the most suitable radiochemical sources for experiments searching for the oscillations of active neutrinos to the light sterile state. In the current work the $\beta$-spectra of ${}^{144}\mathrm{Ce}$ -- ${}^{144}\mathrm{Pr}$ source have been measured by two types of $\beta$-spectrometers based on silicon Si(Li) detectors in order to determine the energy spectrum of electron anti-neutrino emitted in the $\beta$-decay of ${}^{144}\mathrm{Pr}$ nuclei. The nuclear shape factor of the ground state beta transition in ${}^{144}\mathrm{Pr}-{}^{144}\mathrm{Nd}$ has been obtained with high precision: $C(W)=1+(-0.0301\pm 0.0007)W+(-0.101\pm 0.006)W^{-1}$. The reduced cross section for the inverse beta decay reaction on hydrogen for the ${}^{144}\mathrm{Pr}$ electron anti-neutrino source has been defined as $(4.7344\pm 0.0006_{\mathrm{stat}}\pm 0.013_{\mathrm{syst}})\times 10^{-44}\mathrm{c}{\mathrm{m}}^2{\mathrm{decay}}^{-1}$ that provides sufficient sensitivity to search for a sterile neutrino with a mass of $m_4\sim 1$~eV and a mixing angle $Si{n}^2(2{\theta }_{14})\sim 0.005$ using standard disappearance method.

    ↳ nucl-exhep-exhep-phPRD(2025)·0 citations
22. 22*

    Quantum entanglement in cosmology

    Alessio Belfiglio🇮🇹 · Orlando Luongo🇮🇹 · Stefano Mancini🇮🇹

    We discuss recent progress in the study of entanglement within cosmological frameworks, focusing on both momentum and position-space approaches and also reviewing the possibility to directly extract entanglement from quantum fields. Entanglement generation in expanding spacetimes can be traced back to the phenomenon of gravitational particle production, according to which the background gravitational field may transfer energy and momentum to quantum fields. The corresponding entanglement amount and its mode dependence are both sensitive to the field statistics and to the details of spacetime expansion, thus encoding information about the background. Gravitational production processes also play a key role in addressing the quantum-to-classical transition of cosmological perturbations. In order to directly extract entanglement from quantum fields, local interactions with additional quantum systems, working as detectors, have been suggested, leading to the formulation of the entanglement harvesting protocol. Despite harvesting procedures are currently unfeasible from an experimental point of view, various proposals for implementation exist and a proper modeling of detectors and local interactions is crucial to address entanglement extraction via realistic setups. In the final part of the work, we address entanglement characterization in position space, primarily focusing on black hole spacetimes. We first investigate a possible interpretation of Bekenstein-Hawking black hole entropy in terms of the entanglement entropy arising in discrete quantum field theories, on account of the area law. Then, we discuss the resolution of the black hole information paradox via the gravitational fine-grained entropy formula, which provides a new way to compute the entropy of Hawking radiation and allows to preserve unitarity in black hole evaporation processes.

    ↳ gr-qcastro-ph.COhep-phhep-th+1Phys.Rept.(2025)·32 citations
23. 23*

    Accessing proton number fluctuations in limited regions of phase space

    Piotr Bozek🇵🇱

    In heavy ion collisions particle distributions fluctuate from event to event. It is interesting to study local fluctuations of a specific particle specie, e.g. baryons, in the transverse plane. Fluctuations of the harmonic flow provide an integrated measure of such fluctuations. An alternative approach is to study proton number fluctuations measured in a relatively narrow azimuthal angle window. Due to the transverse flow, particles registered in a narrow azimuthal angle window are emitted predominantly from a region of the fireball located at the same azimuthal angle. Similarly, it is informative to measure the covariance of the number of protons emitted in two opposite windows of azimuthal angles. The main difficulty lies in distinguishing effects of local baryon density fluctuations in the transverse plane from global particle density and collective flow fluctuations. These global volume and flow fluctuations can be estimated using some reference particles, e.g. charged mesons. Reliable estimates of such fluctuations can be constructed both for the second factorial cumulant of the proton number in an azimuthal angle window and for the covariance between two such windows. The simultaneous measurement of both quantities provides a sensitive probe of local baryon number fluctuations superimposed on top of a fluctuating fireball background density.

    ↳ nucl-thhep-phnucl-exPRC(2026)·0 citations
24. 24*

    The Infrared Phase of QCD and Anderson Localization

    Ivan Horváth🇨🇿

    When Anderson localization entered the QCD landscape, it was almost immediately thought about in connection with thermal phases, namely as a factor in the chiral transition. However, recent developments revealed an additional structure that made Anderson-like features central to the genesis of the entirely new thermal phase: the IR phase. I will explain these developments.

    ↳ hep-latcond-mat.dis-nnhep-phnucl-thPoS(2025)·3 citations
25. 25*

    Cross-Section Bootstrap: Unveiling the Froissart Amplitude

    Miguel Correia🇨🇦 · Alessandro Georgoudis🇬🇧 · Andrea L. Guerrieri🇨🇭

    We derive a universal bound on the integrated total scattering cross-section at \emph{finite} energies, expressed in terms of a single low-energy coefficient constrained by the non-perturbative S-matrix Bootstrap. At high energies, the bound is compared with proton-proton scattering data; at low energies, with numerical bootstrap results obtained by directly maximizing the cross-section. We conjecture that the amplitude saturating the cross-section at high energies lies at a strongly-coupled corner of the allowed space of low-energy parameters. This universal amplitude exhibits a rising total cross-section, a shrinking elastic differential cross-section with multiple diffractive minima, and a surprisingly rich spectrum of resonances aligning along Regge trajectories, including Pomeron-like and daughter trajectories, as well as unusual ``singular" trajectories in the forward limit which appear deeply interconnected with Froissart growth. Remarkably, the eikonal representation reveals that the scattering is localized within an annular region that slowly expands with energy, challenging the traditional ``disk" diffraction picture. Our results open the door to theoretical and phenomenological studies of \emph{soft} high-energy hadronic scattering via the S-matrix Bootstrap.

    ↳ hep-thhep-phnucl-th19 citations
26. 26*

    Discretely Evanescent Dark Energy

    Nemanja Kaloper🇺🇸

    We propose a new UV-complete dark energy model which is \underbar{\it neither} a cosmological constant nor a slowly rolling scalar field. Our dark energy is the flux of a top form in a hidden sector gauge theory similar to QCD. The top form controls the vacuum energy generated by dark sector CP violation. Its flux discharges by the nucleation of membranes that source it. The tension and charge of the membranes are set by the chiral symmetry breaking scale $\sim 10^{-3}eV$, and the dark energy is a transient. It decays on the order of the current age of the universe. The decays decrease dark energy discretely and randomly, instead of gradually like rolling scalars. Since the decay rate is close to the present Hubble scale, $\Gamma \text{ga}{H}_0^4$, in a time $\sim \mathcal{O}(1/H_0)$ the cosmic acceleration may even cease altogether.

    ↳ hep-thastro-ph.COgr-qchep-phJCAP(2025)·8 citations
27. 27*

    The Nonperturbative Hilbert Space of Quantum Gravity With One Boundary

    Vijay Balasubramanian🇺🇸 · Tom Yildirim🇬🇧

    We discuss a basis for the nonperturbative Hilbert space of quantum gravity with one asymptotic boundary. We use this basis to show that the Hilbert space for gravity with two disconnected boundaries factorizes into a product of two copies of the single boundary Hilbert space.

    ↳ hep-thhep-phJHEP(2026)·20 citations
28. 28*

    Uncalibrated Cosmic Standards as a Robust Test on Late-Time Cosmological Models

    Yihao Wang🇨🇳 · Weikang Lin🇨🇳

    We present an assumption-minimized framework for testing late-time cosmological models using Uncalibrated Cosmic Standards (UCS), including standard rulers and standard candles, without relying on absolute calibrations. The method exploits a tight, model-insensitive correlation between the sound horizons at recombination and the drag epoch. By avoiding dependence on pre-recombination physics and the amplitude of the Cosmic Microwave Background (CMB) power spectra, the UCS framework reduces potential early-Universe biases while retaining much of the constraining power of full analyses. Applying UCS to the recent dynamical dark energy (DE) study that reported deviations from $\Lambda$CDM, we find the constraints shift systematically toward the $\Lambda$CDM case. If this shift is physical, it may result from the omission of some pre-recombination physical processes that influence the scale dependence of the CMB spectra. We also observe a mild tension between uncalibrated standard rulers and candles, which can be largely mitigated by introducing a redshift-dependent magnitude bias in the supernova (SNe Ia) data. Our results highlight the importance of isolating post-recombination observables for testing late-time models in the era of precision cosmology, positioning UCS analysis as a robust framework for upcoming galaxy surveys.

    ↳ astro-ph.COhep-phApJ(2025)·8 citations
29. 29*

    Numerical evolution of self-gravitating halos of self-interacting dark matter

    Marc Kamionkowski🇺🇸 · Kris Sigurdson🇨🇦 · Oren Slone🇮🇱

    We discuss a modification of a recently developed numerical scheme for evolving spherically symmetric self-gravitating systems to include the effects of self-interacting dark matter. The approach is far more efficient than traditional N-body simulations and cross sections with different dependencies on velocity and scattering-angle are easily accommodated. To demonstrate, we provide results of a simulation, which runs quickly on a personal computer, that shows the expected initial flattening of the inner region of an NFW halo as well as the later gravothermal collapse instability that leads to a dense core at the galactic center. We note that this approach can also be used, with some augmentation, to simulate the dynamics in globular clusters by modeling gravitational hard scattering as a self-interaction.

    ↳ astro-ph.COastro-ph.GAhep-phhep-thPRL(2026)·11 citations

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