Fri·Apr 12, 2024Friday·April 12, 2024

1. 01*

   Determination of $K_S^0$ Fragmentation Functions including BESIII Measurements and using Neural Networks

   Maryam Soleymaninia🇮🇷 · Hadi Hashamipour🇮🇷 · Maral Salajegheh🇩🇪 · Hamzeh Khanpour🇮🇷 · Hubert Spiesberger🇩🇪 · Ulf-G. Meißner🇩🇪

   In this study, we revisit the extraction of parton-to-$K_S^0$ hadron fragmentation functions, named FF24-$K_S^0$, focusing on both next-to-leading-order and next-to-next-to-leading-order accuracy in perturbative QCD. Our approach involves the analysis of single inclusive electron-positron annihilation (SIA) data. The two key improvements are, on the one hand, the incorporation of the latest experimental data from the BESIII experiment and, on the other hand, the adoption of Neural Networks in the fitting procedure. To address experimental uncertainties, the Monte Carlo method is employed. Our investigation also explores the impact of hadron mass corrections on the description of SIA data, spanning a broad kinematic regime with a particular emphasis on the range of small $z$ values. The theory prediction for $K_S^0$ production at both NLO and NNLO accuracy exhibits good agreement with experimental data within their respective uncertainties.

   hep-phPRD(2024)·4 citations
2. 02*

   Neutral-current background induced by atmospheric neutrinos at large liquid-scintillator detectors: III. Comprehensive prediction for low energy neutrinos

   Jie Cheng🇨🇳 · Min Li🇨🇳 · Yu-Feng Li🇨🇳 · Gao-Song Li🇨🇳 · Hao-Qi Lu🇨🇳 · Liang-Jian Wen🇨🇳

   Atmospheric neutrinos play a vital role in generating irreducible backgrounds in liquid-scintillator (LS) detectors via their neutral-current (NC) interactions with ${}^{12}$C nuclei. These interactions may affect a wide range of research areas from the MeV to GeV energy range, such as the reactor and geo neutrinos, diffuse supernova neutrino background (DSNB), dark matter, and nucleon decay searches. In this work, we extend our preceding paper, by conducting a first-time systematic exploration of NC backgrounds as low as the MeV region of reactor and geo neutrinos. We utilize up-to-date neutrino generator models from GENIE and NuWro, a TALYS-based nuclear deexcitation package and a GEANT4-based detector simulation toolkit for our complete calculation. Our primary focus is to predict the NC background for experimental searches of inverse-beta-decay signals below the 100 MeV visible energy. In order to have deeper understanding of the characteristics of atmospheric neutrino NC interactions in LS, we investigate the model dependence of NC background predictions by using various data-driven models, including the initial neutrino-nucleon interactions, nuclear ground-state structure, final-state interactions, nuclear deexcitation processes, and secondary interactions of final-state particles.

   hep-phhep-exnucl-thEPJC(2025)·5 citations
3. 03*

   Bayesian Inference with Gaussian Processes for the Determination of Parton Distribution Functions

   Alessandro Candido🇨🇭 · Luigi Del Debbio🇬🇧 · Tommaso Giani🇳🇱 · Giacomo Petrillo🇮🇹

   We discuss a Bayesian methodology for the solution of the inverse problem underlying the determination of parton distribution functions (PDFs). In our approach, Gaussian Processes (GPs) are used to model the PDF prior, while Bayes theorem is used in order to determine the posterior distribution of the PDFs given a set of data. We discuss the general formalism, the Bayesian inference at the level of both parameters and hyperparameters, and the simplifications which occur when the observable entering the analysis is linear in the PDF. We benchmark the new methodology in two simple examples for the determination of a single PDF flavor from a set of Deep Inelastic Scattering (DIS) data and from a set of equal-time correlators computed using lattice QCD. We discuss our results, showing how the proposed methodology allows for a well-defined statistical interpretation of the different sources of errors entering the PDF uncertainty, and how results can be validated a posteriori.

   hep-phhep-latEPJC(2024)·34 citations
4. 04*

   CP Violation in $B\to K{\ell }^{+}{\ell }^{-}$ Decays: New Opportunities in the High-Precision Era

   Robert Fleischer🇳🇱 · Eleftheria Malami🇳🇱 · Anders Rehult🇳🇱 · K. Keri Vos🇳🇱

   Experimental data on rare $B$-meson decays indicate deviations from Standard Model predictions. In studies of these decays, possible new sources of CP violation are often neglected. We discuss CP violation in the rare $B$-meson decays $B\to K{\ell }^{+}{\ell }^{-}(\ell =\mu ,e)$ and point to two phenomena that arise when new sources of CP violation are included. First, the Wilson coefficients $C_{9\ell }$ and $C_{10\ell }$ become complex, and we show how we can extract their values from measurements of direct and mixing-induced CP asymmetries. Second, new sources of CP violation can generate nontrivial lepton flavour universality violation. Such a violation is usually measured through ratios like $R_K$ and $R_{K^{\ast }}$, but we show that measuring only these ratios leaves a large parameter space unexplored. These results bring exciting opportunities to reveal New Physics effects in the high-precision era.

   hep-phPoS(2024)·1 citation
5. 05*

   Dilaton Forbidden Dark Matter

   Thomas Appelquist🇺🇸 · James Ingoldby🇬🇧 · Maurizio Piai🇬🇧

   Dilaton effective field theory (dEFT) describes the long distance behavior of certain confining, near-conformal gauge theories that have been studied via lattice computation. Pseudo-Nambu-Goldstone bosons (pNGBs), emerging from the breaking of approximate, continuous, internal symmetries, are coupled to an additional scalar particle, the dilaton, arising from the spontaneous breaking of approximate scale invariance. This effective theory has been employed to study possible extensions of the standard model. In this paper, we propose a complementary role for dEFT, as a description of the dark matter of the universe, with the pNGBs identified as the dark-matter particles. We show that this theory provides a natural implementation of the "forbidden" dark matter mechanism, and we identify regions of parameter space for which the thermal history of dEFT yields the measured dark matter relic density.

   hep-phhep-latPRD(2024)·22 citations
6. 06*

   Structure-dependent QED in $B^{-}\to {\ell }^{-}\bar{\nu }(\gamma )$

   Matthew Rowe🇬🇧 · Roman Zwicky🇬🇧

   Based on explicitly gauge invariant interpolating operators we compute complete next-leading order QED-corrections for leptonic decays. These are sizeable since the helicity-suppression in V-A interactions allows for structure-dependent collinear logs. We have explicitly checked that these logs are absent for helicity-unsuppressed Yukawa-type transitions. Based on $B\to \gamma$ form factors we present the rates for $B^{-}\to ({\mu }^{-},{\tau }^{-})\bar{\nu }(\gamma )$ in differential and integrated form as a function of the photon energy cut-off $E_{\gamma }^{\text{cut}}$. The effect of the virtual structure-dependent corrections are approximately $+5\%$ and $+3\%$ for the $\mu$- and $\tau$-channel respectively. The structure dependence of the real radiation exceeds that of the virtual one for $E_{\gamma }^{\text{cut}}{|}_{\mu }>0.18(3)$ GeV and is subdominant for the tau channel even when fully inclusive.

   hep-phhep-exhep-latJHEP(2024)·7 citations
7. 07*

   Krylov complexity and gluon cascades in the high energy limit

   Pawel Caputa🇵🇱 · Krzysztof Kutak🇵🇱

   We point out an interesting connection between the mathematical framework of the Krylov basis, which is used to quantify quantum complexity, and the entanglement entropy in high-energy QCD. In particular, we observe that the cascade equation of the dipole model is equivalent to the $SL(2,R)$ Schrodinger equation in the Krylov basis. Consequently, the Krylov complexity corresponds to the average distribution of partons and the Krylov entropy is the counterpart the entanglement entropy computations of \cite{Kharzeev:2017qzs}. Our work not only brings new tools for exploring quantum information and complexity in QCD, but also gives hope for experimental tests of some of the recent, physical probes of quantum complexity.

   hep-phhep-thPRD(2024)·27 citations
8. 08*

   Productions of $X(3872)$/$Z_c(3900)$ and $X_2(4013)$/$Z_c(4020)$ in $Y(4220)$ and $Y(4360)$ decays

   Ming-Zhu Liu🇨🇳 · Xi-Zhe Ling🇨🇳 · Li-Sheng Geng🇨🇳

   The two excited vector charmonium states $Y(4220)$ and $Y(4360)$ are difficult to be understood as pure $c\bar{c}$ charmonium states. Since they are located close to the mass thresholds of $\bar{D}{D}_1$ and ${\bar{D}}^{\ast }{D}_1$, they can be viewed as $\bar{D}{D}_1$ and ${\bar{D}}^{\ast }{D}_1$ molecules. Furthermore, recent studies indicated that the exotic states $X(3872)$/$Z_c(3900)$ and $X_2(4013)$/$Z_c(4020)$ are the isoscalar/isovector $\bar{D}{D}^{\ast }$ and isoscalar/isovector ${\bar{D}}^{\ast }{D}^{\ast }$ molecules, respectively. In this work, in the molecular picture, we employ the triangle diagram mechanism to study the productions of $Z_c(3900)$ and $X(3872)$ in the pionic and radiative decays of $Y(4220)$, as well as their heavy-quark spin symmetry (HQSS) partners, i.e., the productions of $Z_c(4020)$ and $X_2(4013)$ in the pionic and radiative decays of $Y(4360)$. Using the effective Lagrangian approach, we obtain the ratios of the branching fractions $\mathcal{B}[Y(4360)\to Z_c(4020)\pi ]/\mathcal{B}[Y(4220)\to Z_c(3900)\pi ]=1.2$ and $\mathcal{B}[Y(4360)\to X_2(4013)\gamma ]/\mathcal{B}[Y(4220)\to X(3872)\gamma ]=0.5$, almost independent of model parameters, which indicate that the productions of $X_2(4013)$ and $Z_c(4020)$ in the radiative and pionic decays of $Y(4360)$ are likely to be measured in the future. The experimental studies of the predicted decay modes will help verify the molecular nature of $X(3872)$, $Z_c(3900)$, and $Y(4220)$. We hope the present work can stimulate experimental and further theoretical studies on these decay modes.

   hep-phPRD(2024)·17 citations
9. 09*

   Leptonic and semileptonic decays of mesons in the Domain model of QCD vacuum

   Vladimir Voronin🇷🇺

   The leptonic and semileptonic decays of mesons are investigated within the Domain model of QCD vacuum and hadronization. The Domain Model is the mean-field approach based on the statistical ensemble of almost everywhere homogeneous Abelian (anti-)self-dual gluon fields which reproduces main features of low-energy QCD and allows to deduce a nonlocal effective meson action. Using this meson action, the leptonic decay constants, form factors and branching ratios of semileptonic decays are evaluated simultaneously with masses of mesons. The results are compared to experimental data or other approaches.

   hep-phPRD(2024)·2 citations
10. 10*

    Parton-shower effects in polarized deep inelastic scattering

    Ignacio Borsa🇩🇪 · Barbara Jäger🇩🇪

    We present a Monte-Carlo program for the simulation of polarized deep inelastic scattering at next-to-leading order in QCD matched to parton shower programs building on an existing implementation of the unpolarized case in the POWHEG BOX package. We discuss extensions of the POWHEG BOX framework necessary to account for polarized initial states and validate the code by detailed comparisons to existing fixed-order results. We then use the new tool to make predictions for the upcoming Electron Ion Collider. We find that parton-shower effects do have an impact on experimentally accessible distributions and improve the agreement with the next-to-next-to-leading order results.

    hep-phJHEP(2024)·14 citations
11. 11*

    Self-Interacting Dark Sectors in Supernovae Can Behave as a Relativistic Fluid

    Damiano F. G. Fiorillo🇩🇰 · Edoardo Vitagliano🇮🇹

    We revisit supernova (SN) bounds on a hidden sector consisting of millicharged particles $\chi$ and a massless dark photon. Unless the self-coupling is fine-tuned to be small, rather than exiting the SN core as a gas, the particles form a relativistic fluid and subsequent dark QED fireball, streaming out against the drag due to the interaction with matter. Novel bounds due to excessive energy deposition in the mantle of low-energy SNe can be obtained. The cooling bounds from SN 1987A are unexpectedly not affected in the free-streaming regime. The inclusion of $\chi \bar{\chi }\to \mathrm{SM}$ substantially modifies the constraints in the trapping regime, which can only be treated hydrodynamically. Our results can be adapted to generic sub-GeV self-interacting dark sectors.

    hep-phastro-ph.COastro-ph.HEPRL(2024)·57 citations
12. 12*

    Baryon junction effects on charmonium production in pp and pPb collisions

    R. Terra🇧🇷

    In this work we study the effects of the proton and $Pb$ internal structure on charmonium production at high multiplicities. To do this, we assume that the nucleon has an Y shape, which means that the effective quarks (quarks + antiquarks + gluons) are in the extremities of the Y, connected by gluon lines. Since the quarks are in the periphery and the gluons are in the center, as $pp$ collisions go from peripheral to more central and then to ultra-central collisions, the interactions change from quark-quark to gluon-gluon. The enhanced growth of $J/\psi$ occurs because $\sigma (g+g\to c+\bar{c})\gg \sigma (q+\bar{q}\to c+\bar{c})$. In the $p-Pb$ collisions the enhancement is caused by the high concentration of partons in the center of the nuclei. These effects can explain the growth seen in the data and give support to the Y picture of the proton.

    hep-phnucl-th1 citation
13. 13*

    Flavor asymmetry from the non-perturbative nucleon sea

    Yihan Duan🇨🇳 · Siqi Xu🇨🇳 · Shan Cheng🇨🇳 · Xingbo Zhao🇨🇳 · Yang Li🇨🇳 · James P. Vary🇺🇸

    We demonstrate, in the context of a scalar version of the chiral effective field theory, that the multi-sea quark contribution to the nucleon is significant and highly non-trivial in sharp contrast to the prediction of perturbation theory. The non-perturbative calculation is performed in the Fock sector dependent renormalization scheme on the light front, in which the non-perturbative renormalization is incorporated. The calculation suggests that a fully non-perturbative calculation of the chiral EFT is needed to obtain a robust result to be compared with the recent experimental measurement of flavor asymmetry in the proton.

    hep-phnucl-thPRC(2024)·4 citations
14. 14*

    Improved analysis of double $J/\psi$ production in $Z$-boson decay

    Guang-Yu Wang🇨🇳 · Xing-Gang Wu🇨🇳 · Xu-Chang Zheng🇨🇳 · Jiang Yan🇨🇳 · Jia-Wei Zhang🇨🇳

    In this paper, we present an improved calculation for the decay rate of the rare $Z$-boson decay into $J/\psi +J/\psi$. This decay is dominated by the photon fragmentation mechanism, i.e., the transition $Z\to J/\psi +{\gamma }^{\ast }$ followed by the fragmentation ${\gamma }^{\ast }\to J/\psi$. In our calculation, the amplitude of ${\gamma }^{\ast }\to J/\psi$ is extracted from the measured value of $\Gamma (J/\psi \to e^{+}{e}^{-})$, and the amplitude of $Z\to J/\psi +{\gamma }^{\ast }$ is calculate through the light-cone approach. The higher-order QCD and relativistic corrections in the amplitude of ${\gamma }^{\ast }\to J/\psi$ and the large logarithms of $m_{{}_Z}^2/m_c^2$ that appear in the amplitude of $Z\to J/\psi +{\gamma }^{\ast }$ are resummed in our calculation. Besides, the non-fragmentation amplitude is calculated based on the NRQCD factorization, and the next-to-leading order QCD and relativistic corrections are included. The obtained branching fraction for this $Z$ decay channel is $8.66_{-0.69}^{+1.48}\times 10^{-11}$.

    hep-phEPJC(2024)·2 citations
15. 15*

    Trials Factor for Semi-Supervised NN Classifiers in Searches for Narrow Resonances at the LHC

    Benjamin Lieberman🇿🇦 · Salah-Eddine Dahbi🇿🇦 · Andreas Crivellin🇨🇭 · Finn Stevenson🇿🇦 · Nidhi Tripathi🇿🇦 · Mukesh Kumar🇿🇦 · Bruce Mellado🇿🇦

    To mitigate the model dependencies of searches for new narrow resonances at the Large Hadron Collider (LHC), semi-supervised Neural Networks (NNs) can be used. Unlike fully supervised classifiers these models introduce an additional look-elsewhere effect in the process of optimising thresholds on the response distribution. We perform a frequentist study to quantify this effect, in the form of a trials factor. As an example, we consider simulated $Z\gamma$ data to perform narrow resonance searches using semi-supervised NN classifiers. The results from this analysis provide substantiation that the look-elsewhere effect induced by the semi-supervised NN is under control.

    hep-phSciPost Phys.Core(2024)·1 citation
16. 16*

    Approaches to photon absorption in a Lorentz invariance violation scenario

    J. M. Carmona🇪🇸 · J. L. Cortés🇪🇸 · F. Rescic🇪🇸 · M. A. Reyes🇪🇸 · T. Terzić🇭🇷 · F. I. Vrban🇸🇮

    Very high-energy astrophysical gamma rays suffer a suppression of their flux along their propagation due to their interaction, through the $\gamma \gamma \to e^{+}{e}^{-}$ pair-production process, with the soft photon backgrounds present in the Universe. We examine the Universe's transparency to gamma rays within a Lorentz Invariance Violation (LIV) framework, focusing on photon subluminal quadratic corrections driven by a high-energy scale. Based on an explicit calculation, we provide a new expression for the cross section that overcomes the limitations of previous approaches and refines existing constraints for the LIV scale, while we introduce a new approximation that may be useful in LIV scenarios beyond effective field theory. These improvements appear essential for setting constraints on LIV effects with future observations at ultra-high energies, where previous approximations may fall short.

    hep-phastro-ph.HEgr-qcPRD(2024)·10 citations
17. 17*

    On the addition of a large scalar multiplet to the Standard Model

    Darius Jurčiukonis🇱🇹 · Luís Lavoura🇵🇹

    We consider the addition of a single $SU(2)$ multiplet of complex scalar fields to the Standard Model (SM). We explicitly consider the various possible values of the weak isospin $J$ of that multiplet, up to and including $J=7/2$. We allow the multiplet to have arbitrary weak hypercharge. The scalar fields of the multiplet are assumed to have no vacuum expectation value; the mass differences among the components of the multiplet originate in its coupling, present in the scalar potential (SP), to the Higgs doublet of the SM. We derive exact bounded-from-below and unitarity conditions on the SP, thereby constraining those mass differences. We compare those constraints to the ones that may be derived from the oblique parameters.

    hep-phPTEP(2024)·6 citations
18. 18*

    Novel first-order phase transition and critical points in SU(3) Yang-Mills theory with spatial compactification

    Daisuke Fujii🇯🇵 · Akihiro Iwanaka🇯🇵 · Masakiyo Kitazawa🇯🇵 · Daiki Suenaga🇯🇵

    We investigate the thermodynamics and phase structure of $SU(3)$ Yang-Mills theory on ${\mathbb{T}}^2\times {\mathbb{R}}^2$ in Euclidean spacetime in an effective-model approach. The model incorporates two Polyakov loops along two compactified directions as dynamical variables, and is constructed to reproduce thermodynamics on ${\mathbb{T}}^2\times {\mathbb{R}}^2$ measured on the lattice. The model analysis indicates the existence of a novel first-order phase transition on ${\mathbb{T}}^2\times {\mathbb{R}}^2$ in the deconfined phase, which terminates at critical points that should belong to the two-dimensional $Z_2$ universality class. We argue that the interplay of the Polyakov loops induced by their cross term in the Polyakov-loop potential is responsible for the manifestation of the first-order transition.

    hep-phhep-lathep-thPRD(2024)·5 citations
19. 19*

    Quantum computation in fermionic thermal field theories

    Wenyang Qian🇪🇸 · Bin Wu🇪🇸

    Thermal properties of quantum fields at finite temperature are crucial to understanding strongly interacting matter and recent development in quantum computing has provided an alternative and promising avenue of study. In this work, we study thermal field theories involving only fermions using quantum algorithms. We first delve into the presentations of fermion fields via qubits on digital quantum computers alongside the quantum algorithms such as quantum imaginary time evolutions employed to evaluate thermal properties of generic quantum field theories. Specifically, we show numerical results such as the thermal distribution and the energy density of thermal field theories for Majorana fermions in 1+1 dimensions using quantum simulators. In addition to free field theory, we also study the effects of interactions resulting from coupling with a spatially homogeneous Majorana field. In both cases, we show analytically that thermal properties of the system can be described using phase-space distributions, and the quantum simulation results agree with analytical and semiclassical expectations. Our work is an important step to understand thermal fixed points, preparing for quantum simulation of thermalization in real time.

    hep-phhep-lathep-thnucl-th+1JHEP(2024)·11 citations
20. 20*

    Finite modular symmetries and the strong CP problem

    J. T. Penedo🇮🇹 · S. T. Petcov🇮🇹

    Recently, it was shown that modular symmetry may solve the strong CP problem without axions, by producing a vanishing QCD angle while generating a large quark CP violation phase. We extend this framework to finite modular groups, systematically identifying the allowed mass textures. We find quark fields must furnish 1D representations and scan the minimal model landscape.

    hep-phhep-thJHEP(2024)·31 citations
21. 21*

    Quantum tops at circular lepton colliders

    Fabio Maltoni🇧🇪 · Claudio Severi🇬🇧 · Simone Tentori🇧🇪 · Eleni Vryonidou🇬🇧

    We study the quantum properties of top quark pairs in lepton colliders with unpolarised beams, including spin correlations, entanglement, and violation of Bell inequalities. We present analytical results in the SM and in the SMEFT and discuss several practical aspects, like the choice of quantization axes and $t\bar{t}$ threshold effects. We also note a correspondence between parity symmetry and entanglement. We find that quantum observables exhibit a rich phenomenology in the SM, and can also provide additional leverage in detecting new physics residing at higher scales.

    hep-phJHEP(2024)·70 citations
22. 22*

    Finite-temperature renormalization of Standard Model coupled with gravity, and its implications for cosmology

    I. Y. Park🇺🇸

    Finite-temperature one-loop renormalization of the Standard Model, coupled with dynamic metric, is conducted in this study. The entire analysis is coherently carried out by using the refined background field method, applied in the spirit of the Coleman-Weinberg technique. The general form of the propagator, introduced in our previous work to facilitate Feynman diagram computation in a general curved background, proves useful in the presence of time-dependent temperature. Its utilization allows for the renormalization analysis of a FLRW background to essentially reduce to that of a constant finite-T flat spacetime. For infrared physics, the actual curved background should be considered. The implications of our findings for cosmology, particularly the cosmological constant problem and Hubble tension, are discussed.

    ↳ hep-thastro-ph.COgr-qchep-phAnnals Phys.(2025)·5 citations
23. 23*

    Quasinormal modes-shadow correspondence for rotating regular black holes

    Davide Pedrotti🇮🇹 · Sunny Vagnozzi🇮🇹

    Eikonal quasinormal modes (QNMs) of black holes (BHs) and parameters of null geodesics, ultimately tied to the appearance of BHs to external observers, are known to be related, and the eikonal QNM-BH shadow radii correspondence has been extensively studied for spherically symmetric BHs. The extension to rotating BHs is non-trivial, and has been worked out only for equatorial ($m=\pm \ell$) QNMs, or for general modes but limited to the Kerr metric. We extend the QNM-shadow radius correspondence to more general rotating space-times, and argue that the requirements for it to hold amount to conditions on the separability of the Hamilton-Jacobi equation for null geodesics and the Klein-Gordon equation. Metrics obtained by the Newman-Janis algorithm enjoy these conditions, provided certain mathematical requirements are imposed on the line element. We explicitly verify the correspondence for the rotating Bardeen and Hayward regular BHs, both of which satisfy the separability requirements. Our findings show that the QNM-shadow radius correspondence holds for a wide range of axisymmetric space-times beyond Kerr. This paves the way to potential strong-field multi-messenger tests of fundamental physics by hearing (via gravitational wave spectroscopy) and seeing (via VLBI imaging) BHs, although substantial improvements relative to the current observational sensitivity are required to make this possible.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRD(2024)·91 citations
24. 24*

    ${\mathbb{Z}}_3$ lattice gauge theory as a toy model for dense QCD

    Yoshimasa Hidaka🇯🇵 · Yuya Tanizaki🇯🇵 · Arata Yamamoto🇯🇵

    We propose the $(3+1)$-dimensional ${\mathbb{Z}}_3$ lattice gauge theory coupled with the 2-flavor Wilson-Dirac fermion as a toy model for studying quantum chromodynamics (QCD) at nonzero density. We study its phase diagram in the space of the lattice gauge couplings $g^2$ and the quark chemical potentials $\mu$ and discuss the similarity and difference compared with anticipated behaviors of actual QCD. This model also provides a testing ground for various algorithms of the numerical Hamiltonian formalism as its Hilbert space is finite-dimensional in a finite box.

    ↳ hep-lathep-phhep-thPRD(2024)·3 citations
25. 25*

    Symmetric top molecule YbOCH${}_3$ in the fundamental $\mathcal{P}$, $\mathcal{T}$-violation searches

    Anna Zakharova🇷🇺

    The symmetric top molecule YbOCH${}_3$ is studied for its potential to $\mathcal{P}$, $\mathcal{T}$-violation searches. The influence of the rotations and vibrations of the YbOCH${}_3$ on such violating effects as the electron electric dipole moment (eEDM) and the scalar-pseudoscalar electron-nucleon interaction (Ne-SPS) is studied using the coupled channels method. The corresponding sensitivity parameters $E_{\mathrm{eff}}$ and $E_{\mathrm{s}}$ are computed.

    ↳ quant-phhep-phphysics.atom-phphysics.chem-phChem.Phys.Lett.(2024)·3 citations
26. 26*

    Eikonal gravitational-wave lensing in Einstein-aether theory

    Julius Streibert🇩🇪 · Hector O. Silva🇩🇪 · Miguel Zumalacárregui🇩🇪

    Einstein-aether theory provides a model to test the validity of local Lorentz invariance in gravitational interactions. The speed of gravitational waves as measured from the binary neutron star event GW170817 sets stringent limits on Einstein-aether theory, but only on a combination of the theory's free parameters. For this reason, a significant part of the theory's parameter space remains unconstrained by observations. Motivated by this, we explore the propagation of gravitational waves in Einstein-aether theory over an inhomogeneous background (i.e., gravitational wave lensing) as a potential mechanism to break the degeneracies between the theory's free parameters, and hence enable new constraints on the theory to be obtained. We reduce our analysis to gravitational waves that pass far from the lens' center and short wavelength signals, both compared to the lens' gravitational radius (eikonal limit). By applying these approximations and bringing the field equations into the form of the so-called kinetic matrix and applying a formalism known as the propagation eigenstate framework, we find that the speed of gravitational waves is modified by inhomogeneities in the aether field. However, the modification is common to both gravitational polarizations and vanishes in the limit in which gravitational waves propagate with luminal speed. This lens-dependent gravitational wave speed contrasts with the lens-induced birefringence observed in other theories beyond general relativity, like Horndeski's theory. While the potential to improve tests based on gravitational-wave speed is limited, our formalism sets the basis to fully describe signal propagation over inhomogeneous spacetimes in Einstein-aether theory and other extensions of general relativity.

    ↳ gr-qcastro-ph.COastro-ph.HEhep-ph+1PRD(2025)·8 citations
27. 27*

    Efficiency of dynamos from an autonomous generation of chiral asymmetry

    Jennifer Schober🇨🇭 · Igor Rogachevskii🇮🇱 · Axel Brandenburg🇸🇪

    At high energies, the dynamics of a plasma with charged fermions can be described in terms of chiral magnetohydrodynamics. Using direct numerical simulations, we demonstrate that chiral magnetic waves (CMWs) can produce a chiral asymmetry ${\mu }_5={\mu }_{\mathrm{L}}-{\mu }_{\mathrm{R}}$ from a spatially fluctuating (inhomogeneous) chemical potential $\mu ={\mu }_{\mathrm{L}}+{\mu }_{\mathrm{R}}$, where ${\mu }_{\mathrm{L}}$ and ${\mu }_{\mathrm{R}}$ are the chemical potentials of left- and right-handed electrically charged fermions, respectively. If the frequency of the CMW is less than or comparable to the characteristic growth rate of the chiral dynamo instability, the magnetic field can be amplified on small spatial scales. The growth rate of this small-scale chiral dynamo instability is determined by the spatial maximum value of ${\mu }_5$ fluctuations. Therefore, the magnetic field amplification occurs during periods when ${\mu }_5$ reaches temporal maxima during the CMW. If the small-scale chiral dynamo instability leads to a magnetic field strength that exceeds a critical value, which depends on the resistivity and the initial value of $\mu$, magnetically dominated turbulence is produced. Turbulence gives rise to a large-scale dynamo instability, which we find to be caused by the magnetic alpha effect. Our results have consequences for the dynamics of certain high-energy plasmas, such as the early Universe.

    ↳ physics.plasm-phastro-ph.COhep-phPRD(2024)·5 citations
28. 28*

    Distributions and Collision Rates of ALP Stars in the Milky Way

    Dennis Maseizik🇩🇪 · Günter Sigl🇩🇪

    We apply current analytical knowledge on the characteristic mass and linear evolution of miniclusters down to redshift $z=0$ to the hypothetical minicluster distribution of the Milky Way. Using the mass-radius relation and a core-halo relation for stable soliton solutions composed of axion-like particles (ALPs), we connect the galactic minicluster mass distribution to that of their ALP star cores. We consider different temperature evolutions of the ALP field with masses in the range $10^{-12}\mathrm{eV}\le m_a\le 10^{-3}$eV and infer the abundance and properties of QCD axion- and ALP stars in our galaxy. We re-evaluate detection prospects for collisions of neutron stars with both ALP stars and miniclusters as well as relativistic ALP bursts, so-called Bosenovae. Our analysis shows that the collision rates between miniclusters and neutron stars can become as large as $\sim 10^5$yr${}^{-1}$ galaxy${}^{-1}$, but that the fraction of encounters that can lead to resonance between ALP mass and magnetosphere plasma frequency is generally well below $\sim 1$yr${}^{-1}$ galaxy${}^{-1}$, depending on the ALP model. We confirm previous results that merger rates of ALP stars are extremely small $<10^{-12}$yr${}^{-1}$ galaxy${}^{-1}$, while their host miniclusters can merge much more frequently, up to $\sim 10^3$yr${}^{-1}$ galaxy${}^{-1}$ for the QCD axion. We find that Bosenovae and parametric resonance are much more likely to lead to observable signatures than neutron star encounters. We also suggest that a combination of accretion and parametric resonance can lead to observable radio lines for a wide range of ALP masses $m_a$ and photon-couplings $g_{a\gamma \gamma }$.

    ↳ astro-ph.COhep-phPRD(2024)·23 citations
29. 29*

    Astrophysics and Nuclear Physics Informed Interactions in Dense Matter: Inclusion of PSR J0437-4715

    Tuhin Malik🇵🇹 · Veronica Dexheimer🇺🇸 · Constança Providência🇵🇹

    We investigate how vector-isoscalar and vector-isovector interactions can be determined within the density regime of neutron stars (NSs), while fulfilling nuclear and astrophysics constrains. We make use of the Chiral Mean Field (CMF) model, a SU(3) nonlinear realization of the sigma model within the mean-field approximation, for the first time within a Bayesian analysis framework. We show that neutron-matter $\chi$EFT constraints at low density are only satisfied if the vector-isovector mixed interaction term is included, e.g., a ${\omega }^2{\rho }^2$ term. We also show the behavior of the model with respect to the conformal limit. We demonstrate that the CMF model is able to predict a value for the parameter $d_c$ related to the trace anomaly and its derivative takes values below 0.2 above four times saturation density within a hadronic version of the model that does not include hyperons or a phase transition to deconfined matter. We compare these effects with results from other (non-chiral) Relativistic Mean Field models to assess how different approaches to incorporating the same physical constraints affect predictions of NS properties and dense matter equations of state. We also include data from the gravitation wave event GW230529 detected by the LIGO-Virgo-Kagra collaboration and the most recent radius measurement of PSR J0437-4715 from the NASA NICER mission. Our analysis reveals that this new NICER measurement leads to an average reduction of approximately $\sim 0.1$ km radius in the posterior of the NS mass-radius relationship.

    ↳ nucl-thastro-ph.HEgr-qchep-phPRD(2024)·31 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.