Fri·Jul 14, 2023Friday·July 14, 2023

1. 01*

   Gambini-Pullin Electrodynamics as a scenario for Cherenkov radiation in QED vacuum

   Patricio Gaete🇨🇱 · J. A. Helayël-Neto🇧🇷

   We examine the electromagnetic radiation produced by a moving charge in the QED vacuum that behaves as a dispersive medium characterized by a geometrical structure (discreteness/granularity) that emerges from loop quantum gravity. It is shown that the radiation is driven by the refractive vacuum the charged particle travels through reproducing the profile of the Cherenkov effect.

   hep-phhep-thPLB(2023)·3 citations
2. 02*

   Dark baryon from pure Yang-Mills theory and its GW signature from cosmic strings

   Masaki Yamada🇯🇵 · Kazuya Yonekura🇯🇵

   We point out that SO($2N$) pure Yang-Mills theory provides a candidate for dark matter (DM) without the explicit need to impose any additional symmetry. The DM candidate is a particular type of glueball, which we refer to as a baryonic glueball, that is naturally stable and produced by a novel production mechanism for a moderately large $N$. In this case, the intercommutation probability of cosmic strings (or macroscopic color flux tubes) is quite low, which offers characteristic gravitational wave signals to test our model. In particular, our model can simultaneously account for both abundance of DM and the recently reported gravitational wave signals detected in pulsar timing array experiments, including NANOGrav.

   hep-phastro-ph.COastro-ph.HEgr-qc+1JHEP(2023)·44 citations
3. 03*

   Transformation of transverse momentum distributions from Parton Branching to Collins-Soper-Sterman framework

   Armando Bermudez Martinez🇨🇭

   Two main frameworks for defining transverse momentum dependent (TMD) parton densities are the Collins-Soper-Sterman (CSS) formalism, and the Parton Branching (PB) approach. While PB-TMDs have an explicit dependence on a single scale which is used to evolve PB-TMDs in momentum space, TMDs defined in CSS formalism present a double-scale evolution in renormalization and rapidity scales, via a pair of coupled evolution equations. In this letter I leverage the Collins-Soper kernel determined from simulated Drell Yan transverse momentum spectra using PB-TMDs, and provide, for the first time, the transformation of TMD parton distributions from the PB framework to the CSS formalism. The evolved PB-TMDs in $b$-space are compared to the recently released, unpolarized TMD distribution ART23.

   hep-phPLB(2023)·8 citations
4. 04*

   Renormalization Group Evolution with Scalar Leptoquarks

   Sumit Banik🇨🇭 · Andreas Crivellin🇨🇭

   Leptoquarks are theoretically well-motivated and have received increasing attention in recent years as they can explain several hints for physics beyond the Standard Model. In this article, we calculate the renormalisation group evolution of models with scalar leptoquarks. We compute the anomalous dimensions for all couplings (gauge, Yukawa, Higgs and leptoquarks interactions) of the most general Lagrangian at the two-loop level and the corresponding threshold corrections at one-loop. The most relevant analytic results are presented in the Appendix, while the notebook containing the full expressions can be downloaded at https://github.com/SumitBanikGit/SLQ-RG. In our phenomenological analysis, we consider some exemplary cases with focus on gauge and Yukawa coupling unification.

   hep-phJHEP(2023)·4 citations
5. 05*

   Collins-type Energy-Energy Correlators and Nucleon Structure

   Zhong-Bo Kang🇺🇸 · Kyle Lee🇺🇸 · Ding Yu Shao🇨🇳 · Fanyi Zhao🇺🇸

   We generalize the conventional Energy-Energy Correlator (EEC) to include the azimuthal angle dependence, so to define azimuthal angle dependent EEC observables. We study this new EEC observable in $e^{+}{e}^{-}$ and semi-inclusive deep inelastic scattering (SIDIS). In the back-to-back region, we find that the azimuthal angle dependent EEC is sensitive to both the unpolarized EEC jet function and a Collins-type EEC jet function. While the unpolarized EEC jet function is related to the unpolarized transverse momentum dependent (TMD) fragmentation function, the Collins-type EEC jet function is connected with the Collins fragmentation function. We further demonstrate how the new observables allow us to access to the 3D structure of nucleons, especially the spin-dependent ones.

   hep-phhep-ex10 citations
6. 06*

   Post-decay quantum entanglement in top pair production

   J. A. Aguilar-Saavedra🇪🇸

   Top pairs produced at the Large Hadron Collider exhibit quantum entanglement of their spins near threshold and for boosted, central $t\bar{t}$ pairs. The entanglement is maintained between the decay products, in particular between the top quark and the $W^{-}$ boson from the anti-quark (or vice-versa, between $\bar{t}$ and $W^{+}$) in certain kinematical regions. Therefore, $t\bar{t}$ production provides a rare opportunity to verify the spin entanglement between a fermion and a boson. The $tW$ entanglement can be probed at the $7\sigma$ level near threshold with Run 2 data, and at the $5\sigma$ level in the boosted region with the foreseen Run 3 luminosity. In addition, the entanglement between the two $W$ bosons can be probed at the $4\sigma$ level at the LHC Run 3.

   hep-phhep-exPRD(2023)·69 citations
7. 07*

   Spey: smooth inference for reinterpretation studies

   Jack Y. Araz🇬🇧

   Statistical models serve as the cornerstone for hypothesis testing in empirical studies. This paper introduces a new cross-platform Python-based package designed to utilise different likelihood prescriptions via a flexible plug-in system. This framework empowers users to propose, examine, and publish new likelihood prescriptions without developing software infrastructure, ultimately unifying and generalising different ways of constructing likelihoods and employing them for hypothesis testing within a unified platform. We propose a new simplified likelihood prescription, surpassing previous approximation accuracies by incorporating asymmetric uncertainties. Moreover, our package facilitates the integration of various likelihood combination routines, thereby broadening the scope of independent studies through a meta-analysis. By remaining agnostic to the source of the likelihood prescription and the signal hypothesis generator, our platform allows for the seamless implementation of packages with different likelihood prescriptions, fostering compatibility and interoperability.

   hep-phhep-exphysics.data-anstat.MESciPost Phys.(2024)·28 citations
8. 08*

   Hard parton dispersion in the quark-gluon plasma, non-perturbatively

   Jacopo Ghiglieri🇫🇷 · Guy D. Moore🇩🇪 · Philipp Schicho🇩🇪 · Niels Schlusser🇨🇭 · Eamonn Weitz🇫🇷

   The in-medium dispersion of hard partons, encoded in their so-called asymptotic mass, receives large non-perturbative contributions from classical gluons, i.e. soft gluons with large occupation numbers. Here, we discuss how the analytical properties of thermal amplitudes allow for a non-perturbative determination of the infrared classical contribution through lattice determinations in the dimensionally-reduced effective theory of hot QCD, EQCD. We show how these lattice determinations need to be complemented by perturbative two-loop matching calculations between EQCD and QCD, so that the unphysical (classical) ultraviolet behavior of EQCD is replaced by its proper quantum QCD counterpart. We show how lattice and perturbative EQCD are in good agreement in the UV and present an outlook on the two-loop quantum QCD contribution.

   hep-phhep-latnucl-thPoS(2024)·3 citations
9. 09*

   Searching for Exploding Black Holes

   Xavier Boluna🇺🇸 · Stefano Profumo🇺🇸 · Juliette Blé🇺🇸 · Dana Hennings🇺🇸

   The observation of the final stages of the evaporation of a light black hole, which Hawking referred to as ``black hole explosion", would offer critical insights on quantum gravity and high-energy physics phenomena. Here, we explore, review, and revisit the observational features and rates expected for nearby, light, evaporating black holes, and we assess and compare the expected sensitivity of a broad range of observatories. We then focus on the search for candidate black hole explosions in archival data from the Fermi Large Area Telescope and Gamma-ray Burst Monitor, and outline possible future observational campaigns

   ↳ astro-ph.HEastro-ph.COgr-qchep-phJCAP(2024)·24 citations
10. 10*

    Stability of Schwarzshild black holes in quadratic gravity with Weyl curvature domination

    Antonio De Felice🇯🇵 · Shinji Tsujikawa🇯🇵

    We study the linear stability of static and spherically symmetric (SSS) black holes (BHs) in the presence of a Weyl-squared curvature besides an Einstein-Hilbert term in the action. In this theory, there is always an exact Schwarzschild BH irrespective of the Weyl coupling constant $\alpha$, with the appearance of a non-Schwarzschild solution for a particular range of the coupling of order $|\alpha |\approx r_h^2$ (where $r_h$ is the horizon radius). On the SSS background, we show that the propagating degrees of freedom (DOFs) are three in the odd-parity sector and four in the even-parity sector. Since the number of total seven DOFs coincides with those on the Minkowski and isotropic cosmological backgrounds, the Weyl gravity does not pose a strong coupling problem associated with the vanishing kinetic term of dynamical perturbations. The odd-parity perturbations possess at least one ghost mode, but the propagation speeds of all three dynamical modes are luminal. In the even-parity sector, our analysis, based on the WKB approximation, shows that, besides the appearance of at least one ghost mode, the Schwarzschild solution is prone to both radial and angular Laplacian instabilities of several dynamical perturbations for the Weyl coupling in the range $|\alpha |\gg r_h^2$. For large radial and angular momentum modes, the time scales of such instabilities are much shorter than the horizon distance $r_h$ divided by the speed of light. In the coupling regime $|\alpha |\lesssim r_h^2$, the WKB approximation does not hold any longer, and a different analysis should be performed if one wants to state the stability of both the Schwarzschild and non-Schwarzschild BH solutions in this range of model parameters.

    ↳ gr-qcastro-ph.COhep-phhep-thJCAP(2023)·6 citations
11. 11*

    ${\Omega }^{-}$ production as a probe of equation of state of dense matter near the QCD phase transition in relativistic heavy-ion collisions

    Zhi-Min Wu🇨🇳 · Gao-Chan Yong🇨🇳

    The production of doubly strange hyperon ${\Xi }^{-}$ and trebly strange hyperon ${\Omega }^{-}$ in relativistic Au+Au collisions at $\sqrt{s_{NN}}$ = 4.2 GeV is explored based on a relativistic transport model that is interweaved with hadronic mean-field potentials for heavy-ion collisions. Upon comparison, it appears that relative to the double strangeness observable ${\Xi }^{-}$, the yield and collective flows of the triple strange ${\Omega }^{-}$ exhibit a higher sensitivity to the equation of state (EoS) of dense matter. This characteristic makes the ${\Omega }^{-}$ an essential observable for studying the properties of densely formed matter in relativistic heavy-ion collisions.

    ↳ nucl-thhep-phnucl-exPRC(2024)·1 citation
12. 12*

    Studies on $\tau$ decays at Belle II

    Laura Zani🇮🇹

    Tau leptons are powerful tools to probe physics beyond the Standard Model (SM). The Belle II experiment is installed at the SuperKEKB asymmetric energy electron-positron collider and aims at collecting the world's largest sample of tau pair events $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}$. Direct searches for new invisible mediators, charged lepton flavor violation in $\tau$ decays, and tests of the SM via precision measurements of $\tau$ lepton properties and couplings are reported in the following article. The results presented here are based on the data collected by Belle II during 2019-2021.

    ↳ hep-exhep-phJINST(2023)·2 citations
13. 13*

    The study of hadronic rescattering on $K^{\ast 0}$ resonance yield in baryon-rich QCD matter

    Aswini Kumar Sahoo🇮🇳 · Subhash Singha🇨🇳 · Md. Nasim🇮🇳

    The effect of hadronic rescattering on $K^{\ast 0}$ resonance yield can be studied by measuring $K^{\ast 0}/K$ ratio as a function of centrality or multiplicity. This study investigates how the size of the system and the chemical composition (meson-meson versus meson-baryon interaction) of the matter formed in heavy-ion collisions impact the process of hadronic rescattering. It is shown that existing calculation of $K^{\ast 0}/K$ ratio, which considers the interaction of $K^{\ast 0}$ and $K$ mesons with only light mesons in the hadronic medium (neglecting interactions with baryons), fails to explain the measured $K^{\ast 0}/K$ ratio at RHIC BES energies. To understand the multiplicity dependence of the $K^{\ast 0}/K$ ratio at RHIC BES and SPS energies ($\sqrt{s_{NN}}$ $<$ 20 GeV), the Ultra Relativistic Quantum Molecular Dynamics (UrQMD) model is employed. UrQMD calculations suggest that for a given multiplicity, $K^{\ast 0}/K$ is more suppressed in Au+Au collision at $\sqrt{s_{NN}}$ =7.7 GeV, compared to that in $\sqrt{s_{NN}}$ =200 GeV. This is possibly because of formation different type of QCD medium at 200 GeV and 7.7 GeV, and change in interaction cross-section between hadrons with change in particle type and energy.

    ↳ nucl-thhep-phnucl-exJ.Phys.G(2025)·12 citations
14. 14*

    Chiral magnetovortical instability

    Shuai Wang🇨🇳 · Xu-Guang Huang🇨🇳

    We demonstrate that in a chiral plasma subject to an external magnetic field, the chiral vortical effect can induce a new type of magnetohydrodynamic instability which we refer to as the {\it chiral magnetovortical instability}. This instability arises from the mutual evolution of the magnetic and vortical fields. It can cause a rapid amplification of the magnetic fields by transferring the chirality of the constituent particles to the cross helicity of the plasma.

    ↳ nucl-thastro-ph.HEhep-phphysics.flu-dyn+1PRD(2024)·11 citations
15. 15*

    A cosmic microwave background search for fine-structure constant evolution

    Hurum Maksora Tohfa🇺🇸 · Jack Crump🇺🇸 · Ethan Baker🇺🇸 · Luke Hart🇬🇧 · Daniel Grin🇺🇸 · Madeline Brosius🇺🇸 · Jens Chluba🇬🇧

    In some extensions of the standard model of particle physics, the values of the fundamental coupling constants vary in space and time. Some observations of quasars hint at time and spatial variation of the fine structure constant $\alpha$. Here, the Bekenstein-Sandvik-Barrow-Magueijo (BSBM) model (which posits the existence of a scalar field driving evolution in the fundamental electric charge $e$) is tested against quasar and Planck satellite cosmic microwave background (CMB) data. In this model, variations in $e$ are coupled to the matter density through a factor ${\zeta }_{\mathrm{m}}/\omega$, which is related to electromagnetic contributions to nucleon masses, and {the energy} scale of new physics. Simulations conducted here do not support claims that the electrostatic contribution to ${\zeta }_m$ is completely shielded. Other common approximations used in BSBM field evolution are found to be adequate. Principal components of the CMB data with respect to variations in $\alpha$ are used to obtain constraints of ${\zeta }_{\mathrm{m}}/\omega \lesssim 9.3\times 10^{-9}$ for a massless field. A forecast anticipating the promise of the Simons Observatory (SO) CMB experiment shows that SO will be sensitive to values of ${\zeta }_{\mathrm{m}}/\omega \ge 2.2\times 10^{-9}$.

    ↳ astro-ph.COgr-qchep-phPRD(2024)·14 citations
16. 16*

    Nature of the $N^{\ast }$ and $\Delta$ resonances via coupled-channel dynamics

    Yu-Fei Wang🇩🇪 · Ulf-G. Meißner🇩🇪 · Deborah Rönchen🇩🇪 · Chao-Wei Shen🇩🇪

    This work aims at determining the composition of certain $N^{\ast }$ and $\Delta$ resonances, i.e. whether they are compact states formed directly by quarks and gluons, or hadronic molecules generated from the meson-baryon interaction. The information of the resonance poles is provided by a comprehensive coupled-channel approach, the Jülich-Bonn model. $13$ states that are significant in this approach are studied. Two criteria for each state are adopted in this paper, the comparison thereof roughly indicates the model uncertainties. It is found that the conclusions for $8$ resonances are relatively certain: $N(1535){\frac{1}{2}}^{-}$, $N(1440){\frac{1}{2}}^{+}$, $N(1710){\frac{1}{2}}^{+}$, and $N(1520){\frac{3}{2}}^{-}$ tend to be composite; whereas $N(1650){\frac{1}{2}}^{-}$, $N(1900){\frac{3}{2}}^{+}$, $N(1680){\frac{5}{2}}^{+}$, and $\Delta (1600){\frac{3}{2}}^{+}$ tend to be compact.

    ↳ nucl-thhep-phPRC(2024)·21 citations
17. 17*

    PC-Droid: Faster diffusion and improved quality for particle cloud generation

    Matthew Leigh🇨🇭 · Debajyoti Sengupta🇨🇭 · John Andrew Raine🇨🇭 · Guillaume Quétant🇨🇭 · Tobias Golling🇨🇭

    Building on the success of PC-JeDi we introduce PC-Droid, a substantially improved diffusion model for the generation of jet particle clouds. By leveraging a new diffusion formulation, studying more recent integration solvers, and training on all jet types simultaneously, we are able to achieve state-of-the-art performance for all types of jets across all evaluation metrics. We study the trade-off between generation speed and quality by comparing two attention based architectures, as well as the potential of consistency distillation to reduce the number of diffusion steps. Both the faster architecture and consistency models demonstrate performance surpassing many competing models, with generation time up to two orders of magnitude faster than PC-JeDi and three orders of magnitude faster than Delphes.

    ↳ hep-excs.LGhep-phPRD(2024)·45 citations
18. 18*

    Extended-Path Intensity Correlation: Microarcsecond Astrometry with an Arcsecond Field of View

    Marios Galanis🇨🇦 · Ken Van Tilburg🇺🇸 · Masha Baryakhtar🇺🇸 · Neal Weiner🇺🇸

    We develop in detail a recently proposed optical-path modification of astronomical intensity interferometers. Extended-Path Intensity Correlation (EPIC) introduces a tunable path extension, enabling differential astrometry of multiple compact sources such as stars and quasars at separations of up to a few arcseconds. Combined with other recent technological advances in spectroscopy and fast single-photon detection, a ground-based intensity interferometer array can achieve microarcsecond resolution and even better light-centroiding accuracy on bright sources of magnitude $m\lesssim 15$. We lay out the theory and technical requirements of EPIC, and discuss the scientific potential. Promising applications include astrometric lensing of stars and quasar images, binary-orbit characterization, exoplanet detection, Galactic acceleration measurements and calibration of the cosmic distance ladder. The introduction of the path extension thus significantly increases the scope of intensity interferometry while reaching unprecedented levels of relative astrometric precision.

    ↳ astro-ph.IMastro-ph.COastro-ph.SRhep-ph+1PRD(2025)·7 citations
19. 19*

    Illuminating early-stage dynamics of heavy-ion collisions through photons at RHIC BES energies

    Chun Shen🇺🇸 · Abel Noble🇨🇦 · Jean-François Paquet🇺🇸 · Björn Schenke🇺🇸 · Charles Gale🇨🇦

    Heavy-ion collisions at $\sqrt{s_{\mathrm{NN}}}\sim 10$ GeV probe the QCD phase diagram at large baryon densities. Because the longitudinal Lorentz contraction is small at these collision energies, understanding the dynamics during the early phase of the collision is essential for the subsequent modeling of the system evolution and for constraining the QGP transport properties at finite baryon densities. Direct photons provide undistorted information on early-stage dynamics. We model relativistic heavy-ion collisions at RHIC Beam Energy Scan energies with a hybrid dynamical approach consisting of a 3D-Glauber initial state followed by viscous hydrodynamics and hadronic transport (MUSIC + UrQMD). The implemented thermal photon emission takes into account the enhancement from finite baryon chemical potentials. We show that direct photon spectra and their anisotropic flow coefficients have a strong sensitivity to the early stage of heavy-ion collisions. Thus, they provide constraints on QGP dynamics complementary to those obtained from hadronic observables.

    ↳ nucl-thhep-phnucl-exPoS(2024)·8 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.