PaperPanorama

HEP Phenomenology·hep-ph

Thu·May 9, 2024

28 papers15 primary·13 cross-listed·reconstructed*

  1. 01*

    Folded Context Condensation in Path Integral Formalism for Infinite Context Transformers

    Won-Gi Paeng🇰🇷 · Daesuk Kwon🇰🇷 · Kyungwon Jeong🇰🇷 · Honggyo Suh🇰🇷

    In this work, we present a generalized formulation of the Transformer algorithm by reinterpreting its core mechanisms within the framework of Path Integral formalism. In this perspective, the attention mechanism is recast as a process that integrates all possible transition paths leading to future token states, with temporal evolution governed by the Feed-Forward Network. By systematically mapping each component of the Transformer to its counterpart in the Path Integral formulation, we obtain a more compact and efficient representation, in which the contextual information of a sequence is condensed into memory-like segments. These segments are recurrently processed across Transformer layers, enabling more effective long-term information retention. We validate the effectiveness of this approach through the Passkey retrieval task and a summarization task, demonstrating that the proposed method preserves historical information while exhibiting memory usage that scales linearly with sequence length. This contrasts with the non-linear memory growth typically observed in standard attention mechanisms. We expect that this quantum-inspired generalization of the Transformer architecture will open new avenues for enhancing both the efficiency and expressiveness of future Transformer models.

    hep-phcs.AIcs.CLcs.LG+1IEEE Access(2025)·0 citations
  2. 02*

    Mysterious anomalies in Earth's atmosphere and strongly interacting Dark Matter

    Ariel Zhitnitsky🇨🇦 · Marios Maroudas🇩🇪

    It has been recently argued in \cite{Bertolucci:2016xjm, Zioutas:2020ndf, Zioutas:2023ybw} that numerous enigmatic observations remain challenging to explain within the framework of conventional physics. These anomalies include unexpected correlations between temperature variations in the stratosphere, the total electron content of the Earth's atmosphere, and earthquake activity on one hand, and the positions of planets on the other. Decades of collected data provide statistically significant evidence for these observed correlations. The work in \cite{Bertolucci:2016xjm, Zioutas:2020ndf, Zioutas:2023ybw} suggests that these correlations arise from strongly interacting ``streaming invisible matter'' which gets gravitationally focused by the solar system bodies including the Earth's inner mass distribution. Here, we propose that some of these, as well as other anomalies, may be explained by rare yet energetic events involving the so-called axion quark nuggets (AQNs) impacting the Earth. In other words, we identify the ``streaming invisible matter'' conjectured in \cite{Bertolucci:2016xjm, Zioutas:2020ndf, Zioutas:2023ybw} with AQNs, offering a concrete microscopic mechanism to elucidate the observed correlations. It is important to note that the AQN model was originally developed to address the observed similarity between the dark matter and visible matter densities in the Universe \cite{Zhitnitsky:2002qa, Zhitnitsky:2021iwg}, i.e., and not explain the anomalies discussed here. Nonetheless, we support our proposal by demonstrating that the intensity and spectral characteristics of AQN-induced events are consistent with the aforementioned puzzling observations.

    hep-phastro-ph.EPphysics.ao-phSymmetry(2025)·13 citations
  3. 03*

    Axi-Higgs portal Dark Matter via Wess-Zumino mechanism

    Akshay Anilkumar🇮🇳 · Mathew Thomas Arun🇮🇳 · Arjun S. Nair🇮🇳

    We study the axion portal between the visible and the dark sector, where the dark matter is charged under an abelian extension of the Standard Model. In general, such models are anomalous and are rendered gauge invariant by a Stückelberg axion through Wess-Zumino/Green-Schwarz mechanism. Scenarios such as this naturally exist in TeV scale string theory completions of Standard Model. This axion mixes with other Goldstone bosons in the model to give a physical axi-Higgs which becomes massive upon breaking the anomalous gauge group. Such axi-Higgs fields charged under the anomalous symmetry act as mediators for the dark matter annihilation to Standard Model particles and can lead to an efficient freeze-out mechanism. Here, we show that the Stückelberg axion, and the resultant axi-Higgs, with its appropriate shift symmetry cancels the quantum anomalies and also generates the observed relic density for the dark matter. Moreover, we show that the relevant parameter space in our model, where photon production dominates, is safe from {\it Fermi}LAT, Cherenkov Telescope Array, and H.E.S.S. indirect detection experiments.

    hep-phhep-exJCAP(2025)·3 citations
  4. 04*

    Onset of scaling violation in pion and kaon elastic electromagnetic form factors

    Zhao-Qian Yao🇮🇹 · Daniele Binosi🇮🇹 · Craig D. Roberts🇨🇳

    Using a symmetry-preserving truncation of the quantum field equations describing hadron properties, parameter-free predictions are delivered for pion and kaon elastic electromagnetic form factors, , thereby unifying them with kindred results for nucleon elastic electromagnetic form factors. Regarding positive-charge states, the analysis stresses that the presence of scaling violations in QCD entails that should exhibit a single maximum on . Locating such a maximum is both necessary and sufficient to establish the existence of scaling violations. The study predicts that, for charged , mesons, the maximum lies in the neighbourhood GeV. Foreseeable experiments will test these predictions and, providing their reach meets expectations, potentially also provide details on the momentum dependence of meson form factor scaling violation.

    hep-phhep-exhep-latnucl-ex+1PLB(2024)·25 citations
  5. 05*

    Amplitude analysis of decays in a quasi-two-body QCD factorization approach

    J.-P. Dedonder🇫🇷 · R. Kamiński🇵🇱 · L. Leśniak🇵🇱 · B. Loiseau🇫🇷 · P. Żenczykowski🇵🇱

    The decay amplitude is derived within a quasi-two-body QCD factorization framework in terms of kaon form factors and to two-kaon-transition functions. The final state kaon-kaon interactions in the , , and waves are taken into account. The unitarity constraints are satisfied for the two kaons in scalar states. It is shown that with few terms of the full decay amplitude one may reach a fair agreement with the total branching fraction and Dalitz-plot projections published in 2010 by the Belle Collaboration and in 2012 by the Collaboration. With 13 free parameters, our model fits the corresponding 422 data with a of 583.6 which leads to a per degree of freedom equal to 1.43. The dominant branching fraction arises from the mode with 83.0 of the total branching. The next important mode is dominated by plus small and modes with 18.3 of the total. Then follows the mode with 6.2. Adding the other smaller modes, the total percentage sum is 107.7 which indicates a small interference contribution. In most regions of the Dalitz plot, our model gives rather small asymmetry, but in some parts its values can be large and positive or negative. Its predicted total value is equal to -0.11. The calculated time dependent -asymmetry parameters agree, within errors, with those obtained by the analysis. Our model amplitude can be the basis for a parametrization in experimental Dalitz plot analyses of LHCb and Belle II Collaborations.

    hep-phnucl-thPRD(2024)·1 citation
  6. 06*

    Revisiting general dark matter-bound-electron interactions

    Jin-Han Liang🇨🇳 · Yi Liao🇨🇳 · Xiao-Dong Ma🇨🇳 · Hao-Lin Wang🇨🇳

    In this Letter we revisit general dark matter (DM)-bound-electron interactions studied previously in the influential work [R. Catena {\it et al.,} Atomic responses to general dark matter-electron interactions, Phys. Rev. Res. 2, 033195 (2020)] For the most general DM-electron nonrelativistic or relativistic interactions for DM with spin up to 1, we find the average ionization matrix element squared can be organized into three terms, each of which is a product of a DM response function () and a linear combination () of the four atomic response functions () given in that work, . Furthermore, we find a crucial minus sign was missed for the calculation of in that work, which has significant phenomenological consequences when explaining experimental bounds on specific DM scenarios. Due to the corrected sign, there can be significant cancellations between the and terms, so that are dominated by the usual response function in some cases. Many DM scenarios involving DM or electron axial-vector current can yield and thus are potentially affected by the sign. As an example, we show that the recent XENON1T constraint on the fermionic DM anapole moment is weakened by a factor of 2 or so. We also present a complete list of NR operators for spin-1 DM and compute their contributions to the DM response functions.

    hep-phPRD(2024)·16 citations
  7. 07*

    Probing axion-like particles with RF cavities separated by thin barrier

    Dmitry Salnikov🇷🇺 · Petr Satunin🇷🇺 · D. V. Kirpichnikov🇷🇺

    We address the Light-Shining-Through-a-thin-Wall (LSthinW) laboratory setup to estimate the sensitivity of axion-like particle (ALP) detection using two radio-frequency (RF) cavities immersed in a static magnetic field. We analytically evaluate the asymptotic sensitivity in the off-shell regime for the lowest electromagnetic pump modes. We show that a sufficiently thin wall separating can lead to the improved sensitivity of the pure laboratory probes of ALP in the mass range .

    hep-phPLB(2026)·1 citation
  8. 08*

    Constraining the core radius and density jumps inside Earth using atmospheric neutrino oscillations

    Anuj Kumar Upadhyay🇮🇳 · Anil Kumar🇮🇳 · Sanjib Kumar Agarwalla🇮🇳 · Amol Dighe🇮🇳

    Atmospheric neutrinos probe the interior of Earth using weak interactions, and provide information complementary to that of gravitational and seismic measurements. While passing through Earth, multi-GeV neutrinos encounter matter effects due to the coherent forward scattering with ambient electrons, which alter the neutrino oscillation probabilities. These matter effects depend upon the density distribution of electrons inside Earth, and hence, can be used to determine the internal structure of Earth. In this work, we employ a five-layered model of Earth where the layer densities and radii are modified, keeping the mass and moment of inertia of Earth unchanged and respecting the hydrostatic equilibrium condition. We use the proposed INO-ICAL detector as an example of an atmospheric neutrino experiment that can distinguish between neutrinos and antineutrinos efficiently in the multi-GeV energy range. Our analyses demonstrate that such an experiment can simultaneously constrain density jumps inside Earth and locate the core-mantle boundary. The charge identification (CID) capability of the ICAL detector would play a crucial role in obtaining these correlated constraints. An ICAL-like detector without CID capability would also be able to perform this task, albeit with a reduced sensitivity.

    hep-phhep-exphysics.ins-detJHEP(2026)·12 citations
  9. 09*

    Neutrino Oscillations as a Gravitational Wave Detector?

    Dominik Hellmann🇩🇪 · Sara Krieg🇩🇪 · Heinrich Päs🇩🇪 · Mustafa Tabet🇩🇪

    Gravitational waves (GWs) can alter the neutrino propagation distance and thus affect neutrino oscillations. This can result in a complete disappearance of the oscillatory behavior that competes with other sources of neutrino decoherence. We develop a set of criteria that determines under which conditions neutrino oscillations are sensitive to this effect. We find that current or near future neutrino oscillation experiments are not sufficiently sensitive to coherent GW signals but may probe the stochastic gravitational wave background if the energy resolution improves drastically by several orders of magnitude.

    hep-phJCAP(2025)·2 citations
  10. 10*

    Fully Charmed Tetraquark States in Color Structure via QCD Sum Rules

    Chun-Meng Tang🇨🇳 · Chun-Gui Duan🇨🇳 · Liang Tang

    Stimulated by the recent experimental results on the fully-charm tetraquark states, we systematically calculate the mass spectra of the fully-charm tetraquark states in color configuration via QCD sum rules. By constructing nine type currents with quantum numbers and , we perform analytic calculation up to dimension six in the Operator Product Expansion (OPE). We find the fully-charm tetraquark states with lie around 6.48 6.62 GeV while the fully-charm tetraquark states with are about 6.85 7.02 GeV. Notably, the mass predictions for the tetraquarks, specifically those with , align with the broad structure identified by LHCb. Moreover, the masses of fully-charm tetraquarks with and are anticipated to match closely with the mass of X(6900), considering the margin of error. Such findings hint at the presence of some components within the di- structures observed by LHCb. The predictions for tetraquark states with may be accessible in the future BelleII, Super-B, PANDA, and LHCb experiments.

    hep-phEPJC(2024)·27 citations
  11. 11*

    Electroweak Multiplets as Dark Matter candidates: A brief review

    Paolo Panci🇮🇹

    I provide a thorough review of the theoretical and experimental status of ElectroWeak multiplets as Dark Matter candidates, serving as the prototype of Weakly Interacting Massive Particles (WIMPs) Dark Matter. Specifically, the examination includes both real SU(2) representations with zero hypercharge and complex ones with . For the first time, all calculable thermal masses for scalar and fermionic WIMPs are computed, incorporating significant non-perturbative non-relativistic effects such as Sommerfeld enhancement and the formation of WIMP bound states. WIMP masses of few hundred TeV are shown to be compatible both with -wave unitarity of the annihilation cross-section, and perturbativity. Additionally, a strategy is outlined for probing these scenarios in the next generation of experiments.

    hep-phastro-ph.COPoS(2024)·6 citations
  12. 12*

    Longitudinal spin polarization in a thermal model with dissipative corrections

    Soham Banerjee🇮🇳 · Samapan Bhadury🇵🇱 · Wojciech Florkowski🇵🇱 · Amaresh Jaiswal🇮🇳 · Radoslaw Ryblewski🇵🇱

    In this work, we address the problem of longitudinal spin polarization of the hyperons produced in relativistic heavy-ion collisions. We combine a relativistic kinetic-theory framework that includes spin degrees of freedom treated in a classical way with the freeze-out parametrization used in previous investigations. The use of the kinetic theory allows us to incorporate dissipative corrections (due to the thermal shear and gradients of thermal vorticity) into the Pauli-Lubanski vector that determines spin polarization and can be directly compared with the experimental data. As in earlier similar studies, it turns out that a successful description of data can only be achieved with additional assumptions -- in our case, they involve the use of projected thermal vorticity and a suitably adjusted time for spin relaxation (). From our analysis, we find that fm/, which is comparable with other estimates.

    hep-phhep-thnucl-thPRC(2025)·24 citations
  13. 13*

    The Ghent Hybrid Model in NuWro: a new neutrino single-pion production model in the GeV regime

    Qiyu Yan🇨🇳 · Kajetan Niewczas🇧🇪 · Alexis Nikolakopoulos🇺🇸 · Raúl González-Jiménez🇪🇸 · Natalie Jachowicz🇧🇪 · Xianguo Lu🇬🇧 · Jan Sobczyk🇵🇱 · Yangheng Zheng🇨🇳

    Neutrino-induced single-pion production constitutes an essential interaction channel in modern neutrino oscillation experiments, with its products building up a significant fraction of the observable hadronic final states. Frameworks of oscillation analyses strongly rely on Monte Carlo neutrino event generators, which provide theoretical predictions of neutrino interactions on nuclear targets. Thus, it is crucial to integrate state-of-the-art single-pion production models with Monte Carlo simulations to prepare for the upcoming systematics-dominated landscape of neutrino measurements. In this work, we present the implementation of the Ghent Hybrid model for neutrino-induced single-pion production in the NuWro Monte Carlo event generator. The interaction dynamics includes coherently-added contributions from nucleon resonances and a non-resonant background, merged into the pythia branching predictions in the deep-inelastic regime, as instrumented by NuWro. This neutrino-nucleon interaction model is fully incorporated into the nuclear framework of the generator, allowing it to account for the influence of both initial- and final-state nuclear medium effects. We compare the predictions of this integrated implementation with recent pion production data from accelerator-based neutrino experiments. The results of the novel model show improved agreement of the generator predictions with the data and point to the significance of the refined treatment of the description of pion-production processes beyond the region.

    hep-phhep-exnucl-thJHEP(2024)·22 citations
  14. 14*

    Renormalization-Group Improved Resummation of Super-Leading Logarithms

    Philipp Böer🇩🇪 · Patrick Hager🇩🇪 · Matthias Neubert🇺🇸 · Michel Stillger🇩🇪 · Xiaofeng Xu🇩🇪

    A new strategy is presented for systematically treating super-leading logarithmic contributions including higher-order Glauber exchanges for non-global LHC observables in renormalization-group (RG) improved perturbation theory. This represents an important improvement over previous approaches, as it allows for the consistent inclusion of the scale dependence of the strong coupling, thereby providing more reliable estimates of the scale uncertainties in theoretical predictions. The key idea is to rearrange the relevant RG evolution operator in such a way that all double-logarithmic corrections are exponentiated from the outset. This forms the starting point for the first resummation of super-leading logarithms at leading order in RG-improved perturbation theory for arbitrary scattering processes. Moreover, the asymptotic scaling of subleading logarithmic corrections from higher-order Glauber exchanges is determined, demonstrating their parametric suppression.

    hep-phJHEP(2024)·21 citations
  15. 15*

    Optimal Celestial Bodies for Dark Matter Detection

    Rebecca K. Leane🇺🇸 · Joshua Tong🇺🇸

    A wide variety of celestial bodies have been considered as dark matter detectors. Which stands the best chance of delivering the discovery of dark matter? Which is the most powerful dark matter detector? We investigate a range of objects, including the Sun, Earth, Jupiter, Brown Dwarfs, White Dwarfs, Neutron Stars, Stellar populations, and Exoplanets. We quantify how different objects are optimal dark matter detectors in different regimes by deconstructing some of the in-built assumptions in these search sensitivities, including observation potential and particle model assumptions. We find new constraints and future sensitivities across a range of dark matter annihilation final states. We quantify mediator properties leading to detectable celestial-body energy injection or Standard Model fluxes, and show how different objects can be expected to deliver corroborating signals. We discuss different search strategies, their opportunities and limitations, and the interplay of regimes where different celestial objects are optimal dark matter detectors. Deconstructing the assumptions of these searches leads us to point out a new search using the Galactic center stellar population that can provide greater sensitivity to the dark matter-nucleon scattering cross section than the Sun, despite being significantly further away in our Galaxy.

    hep-phastro-ph.EPastro-ph.HEhep-exJCAP(2024)·28 citations
  16. 16*

    Momentum non-conservation in a scalar quantum field theory with a planar interface

    Daniel G. Velázquez🇲🇽 · R. Martínez von Dossow🇲🇽 · Luis F. Urrutia🇲🇽

    Motivated by the recent interest aroused by non-dynamical axionic electrodynamics in the context of topological insulators and Weyl semimetals, we discuss a simple model of the magnetoelectric effect in terms of a -scalar field that interacts through a delta-like potential located at a planar interface. Thus, in the bulk regions the field is constructed by standard free waves with the absence of evanescent components. These waves have to be combined into linear superposition to account for the boundary conditions at the interface in order to yield the corresponding normal modes. Our aim is twofold: first we quantize the -scalar field using the normal modes in the canonical approach and then we look for applications emphasizing the effect of momentum non-conservation due to the presence of the interface. To this end we calculate the decay of a standard scalar particle into two -scalar particles showing the opening of new decay channels. As a second application we deal with the two body scattering of standard charged scalar particles mediated by a -scalar particle, focusing on the momentum non-conserving contribution of the scattering amplitude . We define a generalization of the usual cross section in order to quantify the emergence of these events. We also study the allowed kinematical region for momentum non-conservation as well as the position of the poles of the amplitude . Finally, the ratio of the magnitudes between and the momentum conserving amplitude is discussed in the appropriate region of momentum space.

    hep-thhep-phEur.Phys.J.Plus(2024)·0 citations
  17. 17*

    Nonradial instabilities in anisotropic neutron stars

    Shu Yan Lau🇺🇸 · Siddarth Ajith🇺🇸 · Victor Guedes🇺🇸 · Kent Yagi🇺🇸

    Non-radial oscillation modes of a neutron star possess valuable information about its internal structure and nuclear physics. Starting from the quadrupolar order, such modes under general relativity are known as quasi-normal modes since they dissipate energy through gravitational radiation and their frequencies are complex. The stability of these modes is governed by the sign of the imaginary part of the frequency, which determines whether the mode would decay or grow over time. In this Letter, we develop a fully consistent framework in general relativity to study quasi-normal modes of neutron stars with anisotropic pressure, whose motivation includes strong internal magnetic fields and non-vanishing shear or viscosity. We employ parametrized models for the anisotropy and solve the perturbed Einstein field equations numerically. We find that, unlike the case for isotropic neutron stars, the imaginary parts of some of the pressure (-)modes flip signs as the degree of anisotropy deviates from zero, depicting a transition from stable modes to unstable modes. This finding indicates that some anisotropic neutron star models are unstable, potentially restricting the form of sustained anisotropy.

    gr-qcastro-ph.HEhep-phPRD(2024)·13 citations
  18. 18*

    Effect of dark matter interaction on hybrid star in the light of the recent astrophysical observations

    Suman Pal🇮🇳 · Gargi Chaudhuri🇮🇳

    We have explored the effect of dark matter interaction on hybrid star (HS) in the light of recent astrophysical observational constraints. The presence of dark matter is assumed to be there in both the hadron as well as the quark sector. The dark matter particle interacts with both hadron and quark matter through the exchange of a scalar as well as a vector meson. The equation of state (EOS) of the hadron part is computed using the NL3 version of the relativistic mean field(RMF) model, whereas the quark part is taken care of using the well-known MIT Bag model with the vector interaction. We investigate the effect of the dark matter density and the mass of the dark matter particle on various observables like mass, radius, tidal deformability of the dark matter admixed hybrid star(DMAHS). In this study, we have noted an intriguing aspect that is the speed of sound in the DMAHS is insensitive to both the mass as well as the density of dark matter. We also observe a striking similarity in the variation of transition mass and its corresponding radius, as well as the maximum mass of neutron stars, with dark matter density and mass. We employ observational constraints from neutron stars to narrow down the allowed range of the parameters of dark matter.

    nucl-thhep-phJCAP(2024)·13 citations
  19. 19*

    Sedimentary rocks from Mediterranean drought in the Messinian age as a probe of the past cosmic ray flux

    Lorenzo Caccianiga🇮🇹 · Claudio Galelli🇫🇷 · Lorenzo Apollonio🇮🇹 · Federico Maria Mariani🇮🇹 · Paolo Magnani🇮🇹 · Alessandro Veutro🇮🇹

    We propose the use of natural minerals as detectors to study the past flux of cosmic rays. This novel application of the \textit{paleo-detector} technique requires a specific approach as it needs samples that have been exposed to secondary cosmic rays for a well defined period of time. We suggest here the use of the evaporites formed during the desiccation of the Mediterranean sea Myr ago. These minerals have been created and exposed to the air or under a shallow water basin for kyr before being quickly submerged again by a km-scale overburden of water. We show that, by looking at the damages left in the minerals by muons in cosmic ray showers, we could detect differences in the primary cosmic ray flux during that period, as the ones expected from nearby supernova explosions, below the percent-level. We show also that little to no background from radioactive contamination and other astroparticles is expected for this kind of analysis.

    astro-ph.HEhep-phphysics.geo-phPRD(2024)·7 citations
  20. 20*

    ATLAS searches for additional scalars and exotic Higgs boson decays with the LHC Run 2 dataset

    ATLAS Collaboration

    This report reviews the published results of searches for possible additional scalar particles and exotic decays of the Higgs boson performed by the ATLAS Collaboration using up to 140 fb of 13 TeV proton-proton collision data collected during Run 2 of the Large Hadron Collider. Key results are examined, and observed excesses, while never statistically compelling, are noted. Constraints are placed on parameters of several models which extend the Standard Model, for example by adding one or more singlet or doublet fields, or offering exotic Higgs boson decay channels. Summaries of new searches as well as extensions of previous searches are discussed. These new results have a wider reach or attain stronger exclusion limits. New experimental techniques that were developed for these searches are highlighted. Search channels which have not yet been examined are also listed, as these provide insight into possible future areas of exploration.

    hep-exhep-phPhys.Rept.(2025)·57 citations
  21. 21*

    Bounds on the charge of the graviton using gravitational wave observations

    Sreejith Nair🇮🇳 · Aditya Vijaykumar🇨🇦 · Sudipta Sarkar🇮🇳

    If the graviton possesses a non-zero charge , gravitational waves (GW) originating from astrophysical sources would experience an additional time delay due to intergalactic magnetic fields. This would result in a modification of the phase evolution of the observed GW signal similar to the effect induced by a massive graviton. As a result, we can reinterpret the most recent upper limits on the graviton's mass as constraints on the joint mass-charge parameter space, finding where represents the charge of an electron. Additionally, we illustrate that a charged graviton would introduce a constant phase difference in the gravitational waves detected by two spatially separated GW detectors due to the Aharonov-Bohm effect. Using the non-observation of such a phase difference for the GW event GW190814, we establish a mass-independent constraint . To the best of our knowledge, our results constitute the first-ever bounds on the charge of the graviton. We also discuss various caveats involved in our measurements and prospects for strengthening these bounds with future GW observations.

    gr-qcastro-ph.HEhep-phhep-thJCAP(2024)·7 citations
  22. 22*

    Mass function of stellar black holes as revealed by the LIGO-Virgo-KAGRA observations

    Xiao-Fei Dong🇨🇳 · Yong-Feng Huang🇨🇳 · Zhi-Bin Zhang🇨🇳 · Xiu-Juan Li🇨🇳 · Ze-Cheng Zou🇨🇳 · Chen-Ran Hu🇨🇳 · Chen Deng🇨🇳 · Yang Liu🇨🇳

    Ninety gravitational wave events have been detected by the LIGO-Virgo-KAGRA network and are released in the Gravitational-Wave Transient Catalog. Among these events, 83 cases are definitely binary black hole mergers since the masses of all the objects involved significantly exceed the upper limit of neutron stars. The black holes in these merger events naturally form two interesting samples, a pre-merger sample that includes all the black holes before the mergers and a post-merger sample that consists of the black holes generated during the merging processes. The former represents black holes that once existed in the Universe, while the latter represents newly born black holes. Here we present a statistical analysis on these two samples. The non-parametric statistic method is adopted to correct for the observational selection effect. The Lynden-Bell's method is further applied to derive the mass distribution and density function of black holes. It is found that the mass distribution can be expressed as a broken power-law function. More interestingly, the power-law index in the high mass region is comparable for the two samples. The number density of black holes is found to depend on redshift as -- based on the two samples. Implications of these findings on the origin of black holes are discussed.

    gr-qcastro-ph.HEhep-phApJ(2024)·3 citations
  23. 23*

    Dark photon constraints from CMB temperature anisotropies

    Andres Aramburo-Garcia🇳🇱 · Kyrylo Bondarenko🇸🇪 · Alexey Boyarsky🇳🇱 · Pavlo Kashko🇧🇪 · Josef Pradler🇦🇹 · Anastasia Sokolenko🇺🇸 · Roi Kugel🇳🇱 · Matthieu Schaller🇳🇱 · Joop Schaye🇳🇱

    The resonant conversion, within the inter-galactic medium, of regular photons into dark photons amplifies the anisotropy observed in the CMB, thereby imposing stringent constraints on the existence of light dark photons. In this study, we investigate the impact of light dark photons, with masses in the range on the power spectrum of temperature anisotropies within the cosmic microwave background (CMB) radiation utilizing the state-of-the-art large-volume FLAMINGO cosmological simulations. Our results show that using full Planck data, one can expect the existing constraints on the dark photon mixing parameter in this mass range to improve by an order of magnitude.

    astro-ph.COhep-phJCAP(2024)·13 citations
  24. 24*

    Asymmetric Symmetry Breaking: Unequal Probabilities of Vacuum Selection

    Tian-Chi Ma🇨🇳 · Han-Qing Shi🇨🇳 · Hai-Qing Zhang🇨🇳

    Spontaneous symmetry breaking is a fundamental notion in modern physics, ranging from high energy to condensed matter. However, the usual spontaneous symmetry breaking only considers the equal probability to select the vacua. In this work, we conceive a model to realize the unequal probability of the symmetry breaking, leading to an unbalanced number of ground states. Specifically, we study the probabilities of a scalar field to roll down from the top of a potential, where the top is only continuous. As the whole system is subject to random perturbations, we find that the probability for the field to roll down to the left or right side depends the square root of the second derivative of the potential at the top. We solve this problem theoretically by using the Fokker-Planck equations in stochastic process and verify our findings numerically. This study may potentially be a new mechanism to explain the origins of asymmetries in the Universe.

    hep-thcond-mat.supr-congr-qchep-ph2 citations
  25. 25*

    Neutrinos and gamma rays from beta decays in an active galactic nucleus NGC 1068 jet

    Koichiro Yasuda🇺🇸 · Nobuyuki Sakai🇯🇵 · Yoshiyuki Inoue🇯🇵 · Alexander Kusenko🇺🇸

    We show that TeV neutrinos and high-energy gamma rays detected from the nearby active galaxy NGC 1068 can simultaneously be explained in a model based on the beta decays of neutrons produced in the photodisintegration of 4He nuclei on ultraviolet photons in the jet. The photodisintegration of nuclei occurs at energies above several PeV, which explains the 1-100 TeV energies of the observed neutrinos. The TeV gamma-ray flux accompanying the beta decays is expected to be much lower than the neutrino flux, which agrees with the observations of NGC 1068 showing a gamma-ray deficit as compared to the expectations from proton-photon interactions. Furthermore, the synchrotron and inverse Compton gamma-ray flux associated with protons' Bethe-Heitler pair production and the photopion processes in the jet can be consistent with the observed gamma-ray flux at GeV energies for a plausible range of magnetic fields of jets. This scenario, combining beta decay and Bethe-Heitler, can be applied to other jet Seyfert galaxies such as NGC 4151. Future measurements of the neutrino flavor ratio can help confirm the beta-decay origin of the observed neutrinos.

    astro-ph.HEhep-phPRL(2025)·17 citations
  26. 26*

    Fermi-Dirac Integrals in Degenerate Regimes: A Novel Asymptotic Expansion

    Jeremiah Birrell🇺🇸 · Martin Formanek🇨🇿 · Andrew Steinmetz🇺🇸 · Cheng Tao Yang🇺🇸 · Johann Rafelski🇺🇸

    We characterize in a novel manner the physical properties of the low temperature Fermi gas in the degenerate domain as a function of temperature and chemical potential. For the first time we obtain low temperature results in the domain where several fermions are found within a de Broglie spatial cell. In this regime, the usual high degeneracy Sommerfeld expansion fails. The other known semi-classical Boltzmann domain applies when fewer than one particle is found in the de Broglie cell. We also improve on the understanding of the Sommerfeld expansion in the regime where the chemical potential is close to the mass and also in the high temperature regime. In these calculcations we use a novel characterization of the Fermi distribution allowing the separation of the finite and zero temperature phenomena. The relative errors of the three approximate methods (Boltzmann limit, Sommerfeld expansion, and the new domain of several particles in the de Broglie cell) are quantified.

    cond-mat.quant-gasastro-ph.COhep-phnucl-thInt.J.Theor.Phys.(2024)·3 citations
  27. 27*

    Swampland Conjectures Constraints on Dark Energy from a Highly Curved Field Space

    Guillaume Payeur🇨🇦 · Evan McDonough🇨🇦 · Robert Brandenberger🇨🇦

    We study the interplay of the trans-Planckian censorship conjecture (TCC) and the swampland distance conjecture (SDC) in the context of multifield dark energy in a curved field space. In this scenario, the phase of accelerated expansion is realized as non-geodesic motion in a highly-curved field space, reminiscent of models developed in the context of inflation. The model features a stable attractor solution with near constant equation of state , and predicts that the current era of accelerated expansion is eternal. The latter implies an eventual conflict with the TCC, which holds that the duration of any epoch of cosmic acceleration is bounded by the requirement that the large-scale observable universe is blind to Planck-scale early universe physics. This tension can be resolved by an interplay with the distance conjecture: for suitable parameter values, the apparent violation of the TCC occurs well after the fields have traversed a Planckian distance. The SDC then predicts a breakdown of the effective field theory (EFT) before the TCC can be violated. We derive the constraints on the model arising from the SDC+TCC and the de Sitter conjecture. We demonstrate that the model can be consistent with both swampland conjectures and observational data from Planck 2018 and the Dark Energy Spectroscopic Instrument.

    hep-thastro-ph.COgr-qchep-phPRD(2024)·14 citations
  28. 28*

    Impact of a plasma on the relaxation of black holes

    Enrico Cannizzaro🇮🇹 · Thomas F.M. Spieksma🇩🇰 · Vitor Cardoso🇩🇰 · Taishi Ikeda🇩🇰

    Our universe is permeated with interstellar plasma, which prevents propagation of low-frequency electromagnetic waves. Here, we show that two dramatic consequences arise out of such suppression; (i) if plasma permeates the light ring of a black hole, electromagnetic modes are screened entirely from the gravitational-wave signal, changing the black hole spectroscopy paradigm; (ii) if a near vacuum cavity is formed close to a charged black hole, as expected for near equal-mass mergers, ringdown "echoes" are excited. The amplitude of such echoes decays slowly and could thus serve as a silver bullet for plasmas near charged black holes.

    gr-qcastro-ph.HEhep-phPRD(2024)·19 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.