Tue·Nov 21, 2023Tuesday·November 21, 2023

1. 01*

   New $\mu$ Forces From ${\nu }_{\mu }$ Sources

   Cari Cesarotti🇺🇸 · Yonatan Kahn🇺🇸 · Gordan Krnjaic🇺🇸 · Duncan Rocha🇺🇸 · Joshua Spitz🇺🇸

   Accelerator-based experiments reliant on charged pion and kaon decays to produce muon-neutrino beams also deliver an associated powerful flux of muons. Therefore, these experiments can additionally be sensitive to light new particles that preferentially couple to muons and decay to visible final states on macroscopic length scales. Such particles are produced through rare 3-body meson decays in the decay pipe or via muon scattering in the beam dump, and decay in a downstream detector. To demonstrate the potential of this search strategy, we recast existing MiniBooNE and MicroBooNE studies of neutral pion production in neutrino-induced neutral-current scattering (${\nu }_{\mu }N\to {\nu }_{\mu }N{\pi }^0,{\pi }^0\to \gamma \gamma$) to place new leading limits on light ($<2m_{\mu }$) muon-philic scalar particles that decay to diphotons through loops of virtual muons. Our results exclude scalars of mass between 10 and 60 MeV in which this scenario resolves the muon $g-2$ anomaly. We also make projections for the sensitivity of SBND to these models and provide a road map for future neutrino experiments to perform dedicated searches for muon-philic forces.

   hep-phhep-exPRD(2024)·11 citations
2. 02*

   When sound wave meets the neutrino anomaly

   Jae Jun Kim🇺🇸

   We propose that the sound wave coming to the inner side of Miniboone detector could be one of the sources for our having the neutrino anomaly in the experiment. We start with presenting a rough estimate for the size of the energy associated with the sound wave coming into the detector, the size of the loss of energy associate with the save wave as it travels down to the target medium due to their gravitationally interacting with the sound wave in a classical sense. After that, we describe that the neutrino anomaly could be due to the sound wave interacting with the detector material under the pressure due to the presence of the mineral oil and their producing phonon-induced electrons via a process such as the thermionic emission, which may lead more events to be identified as electron-like events in the experiment. We also address that the sound wave may scatter with the electrons produced from the electron-photon shower.

   hep-phhep-exphysics.ins-det0 citations
3. 03*

   HL-LHC sensitivity to higgsinos from natural SUSY with gravitino LSP

   Jian-Peng Dai🇨🇳 · Song Li🇨🇳 · Jin-Min Yang🇨🇳 · Yang Zhang🇨🇳 · Pengxuan Zhu🇨🇳 · Rui Zhu🇨🇳

   In the realm of natural supersymmetric models, higgsinos are typically the lightest electroweakinos. In gauge-mediated supersymmetry breaking models, the lightest higgsino-dominated particles decay into a $Z$-boson or a Higgs boson ($h$), along with an ultra-light gravitino ($\tilde{G}$) serving as the lightest supersymmetric particle (LSP). This scenario suggests a significant non-resonant $hh$ production. Basing on the recent global fitting results of the $\tilde{G}$-EWMSSM (MSSM with light electroweakinos and an eV-scale gravitino as the LSP) performed by the \textsf{GAMBIT} collaboration, which support a higgsino dominated electroweakino as light as 140 GeV, we develop two simplified models to evaluate their detection potential at the high-luminosity LHC (HL-LHC) with $\sqrt{s}=14\mathrm{TeV}$ and an integrated luminosity of $3000{\mathrm{fb}}^{-1}$. The first model examines the processes where heavier higgsino-dominated states decay into soft $W/Z$ bosons, while the second focuses on direct decays of all three higgsino-dominated electroweakinos into $W/Z/h$ plus a $\tilde{G}$. Our study, incorporating both models and their distinct decay channels, utilizes detailed Monte Carlo simulations for signals and standard model backgrounds. We find that the HL-LHC can probe higgsinos up to 575 GeV, potentially discovering or excluding the natural SUSY scenario in the context of a gravitino LSP. Further, we reinterpret this discovery potential using the GAMBIT global fit samples, and find that the entire parameter space of $|\mu |\le 500\mathrm{GeV}$ with an electroweak fine-tuning measure (${\Delta }_{\mathrm{EW}}$) under 100 in $\tilde{G}$-EWMSSM is accessible at the HL-LHC.

   hep-phEPJC(2024)·4 citations
4. 04*

   Comparison of CMS measurements with predictions at NLO applying the Parton Branching Method and PYTHIA

   Fernando Guzman · Si Hyun Jeon · Hannes Jung🇩🇪 · Danyer Perez Adan · Sara Taheri Monfared🇩🇪 · Fateme Almaksusi · Daniel Belmonte Perez · Dorukhan Boncukcu · Aleksandr Boger · Emmanuel Botero Osorio · Isadora Bozza Galvão · Juan Esteban Ospina Holguin and 22 other authors

   In August 2023, more than 30 students joined the Special Remote DESY summer-school to work on projects of importance for LHC experiments. In a dedicated initiative, analyses that had not been incorporated into the RIVET package were implemented and verified. Here, a brief description of the accomplished work is given, and a comparison of the measurements with predictions obtained from matched standard parton shower Monte Carlo event generators as well as with those obtained from Parton-Branching TMDs with corresponding parton showers are presented.

   hep-ph0 citations
5. 05*

   Bottomonia production in Modified NRQCD

   Sudhansu S. Biswal🇮🇳 · Monalisa Mohanty🇮🇳 · K. Sridhar🇮🇳

   Motivated by the success of Modified Non-Relativistic Quantum Chromodynamics (Modified NRQCD) in explaining data from experiments at the Large Hadron Collider (LHC) for charmonia, we now turn to the study of bottomonium production at the LHC. Modified NRQCD does very well in explaining ${\rm Y}$ data from the LHC. But this is true also of NRQCD which explains the ${\rm Y}$ data equally well. Where the two models differ substantially is in their predictions for ${\eta }_b$ production. As was the case with ${\eta }_c$, the measurement of ${\eta }_b$ production at the LHC will be another decisive test of Modified NRQCD.

   hep-phhep-exJ.Subatomic Part.Cosmol.(2025)·5 citations
6. 06*

   Analysis of the $Z_b(10650)$ state based on electromagnetic properties

   U. Özdem🇹🇷

   In this study, the magnetic and quadrupole moments of the $Z_b(10650)$ state are determined using the compact diquark-antidiquark interpolating current through the QCD light-cone sum rule. The values that are obtained as a result of the analysis are as follows: ${\mu }_{Z_b}=2.35_{-0.33}^{+0.34}{\mu }_N$ and ${\mathcal{D}}_{Z_b}=(1.82_{-0.31}^{+0.35})\times 10^{-2}\text{mbox}{fm}^2$. Examining the results obtained, it can be seen that the magnetic moments are large enough to be measured experimentally, while the quadrupole moment is obtained as a small but non-zero value, corresponding to a prolate charge distribution. The magnetic moment is the leading-order response of a bound system to a weak external magnetic field. It therefore provides an excellent platform to probe the internal structures of hadrons governed by the quark-gluon dynamics of QCD.

   hep-phhep-exhep-latEPJC(2024)·9 citations
7. 07*

   Open charm production cross section from combined LHC experiments in $pp$ collisions at $\sqrt{s}=5.02$ TeV

   Christian Bierlich🇸🇪 · Jeremy Wilkinson🇩🇪 · Jiayin Sun🇮🇹 · Giulia Manca🇮🇹 · Raphael Granier de Cassagnac🇫🇷 · Jacek Otwinowski🇵🇱

   Open charm production in proton-proton collisions represents an important tool to investigate some of the most fundamental aspects of Quantum Chromodynamics, from the partonic mechanisms of heavy-quark production to the process of heavy-quark hadronisation. Over the last decade, the measurement of the production cross sections of charm mesons and baryons in proton-proton (pp) collisions was at the centre of a wide experimental effort at the Large Hadron Collider. Thanks to the complementarity of the different experiments, the production of charm hadrons was measured over a wide transverse momentum region and in different rapidity ranges. In this paper, the measurements of the charm hadrons $D^0$, $D^{\ast }$, $D^{+}$, $D_s^{+}$, ${\Lambda }_c^{+}$ and ${\Xi }_c^0$ performed by the ALICE, CMS and LHCb collaborations in pp collisions at the centre-of-mass energy $\sqrt{s}=5.02\mathrm{TeV}$ are combined to determine the total charm-quark production cross section ${\sigma }_{c\overline{c}}$ in a novel data-driven approach. The resulting total $c\overline{c}$ cross section is \begin{equation*} \begin{aligned} \sigma_\mathrm{c\overline{c}} (\mathrm{pp},5.02\,\mathrm{TeV}) ={} & 8340.9 \pm 217.8\mathrm{ (stat.) } {}^{+367.1}_{-367.2} \mathrm{ (syst.) } {}^{+362.5}_{-457.5} \mathrm{ (extr.) } + 679.9 (\Omega_\mathrm{c})~\mu\mathrm{b}. \end{aligned} \end{equation*} The measured charm-hadron distributions and corresponding cross sections are compared with the most recent theoretical calculations.

   hep-phEur.Phys.J.Plus(2024)·16 citations
8. 08*

   Universal Symmetry and its Soft Breaking in Renormalizable Supersymmetric Field Theory

   Ernest Ma🇺🇸

   It is pointed out that every renormalizable supersymmetric field theory has a symmetry which is hidden in plain sight, but is usually broken by soft terms which obey supersymmetry. On the other hand, the terms which break supersymmetry softly may or may not break this symmetry. Implications for the minimal supersymmetric standard model (MSSM) are discussed.

   hep-phhep-th1 citation
9. 09*

   Rapidity and Energy Dependences of Temperatures and Volume Extracted from Identified Charged Hadron Spectra in Proton-Proton Collisions at a Super Proton Synchrotron (SPS)

   Pei-Pin Yang🇨🇳 · Fu-Hu Liu🇨🇳 · Khusniddin K. Olimov🇺🇿

   The standard (Bose-Einstein/Fermi-Dirac or Maxwell-Boltzmann) distribution from the relativistic ideal gas model is used to study the transverse momentum ($p_T$) spectra of identified charged hadrons (${\pi }^{-}$, ${\pi }^{+}$, $K^{-}$, $K^{+}$, $\bar{p}$, and $p$) with different rapidities produced in inelastic proton-proton ($pp$) collisions at the Super Proton Synchrotron (SPS). The experimental data measured by the NA61/SHINE Collaboration at the center-of-mass (c.m.) energies $\sqrt{s}=6.3$, 7.7, 8.8, 12.3, and 17.3 GeV are fitted well by the distribution. It is shown that the effective temperature ($T_{eff}$ or $T$), kinetic freeze-out temperature ($T_0$), and initial temperature ($T_i$) decrease with the increase in rapidity and increase with the increase in c.m. energy. The kinetic freeze-out volume ($V$) extracted from the ${\pi }^{-}$, ${\pi }^{+}$, $K^{-}$, $K^{+}$, and $\bar{p}$ spectra decreases with the rapidity and increase with the c.m. energy. The opposite tendency of $V$, extracted from the $p$ spectra, is observed to be increasing with the rapidity and decreasing with the c.m. energy due to the effect of leading protons.

   hep-phhep-exnucl-exnucl-thEntropy(2023)·7 citations
10. 10*

    Hadronic Vacuum Polarization Contribution to ${\mathbf{g}}_{\mathbf{\mu }}-2$ as a function of the external lepton mass

    David Greynat🇫🇷 · Eduardo de Rafael🇫🇷

    The hadronic vacuum polarization contribution to the anomalous magnetic moment of a lepton is considered as a function of the lepton mass. We show how the analyticity properties of this function allow for its full reconstruction when it is only known in a restricted mass region. Assuming that LQCD could evaluate it in an optimal mass region we show, within the framework of a phenomenological model, how to reconstruct the function elsewhere, in particular at the muon mass value.

    hep-phhep-lathep-th1 citation
11. 11*

    Phenomenological Implications of $\mathbf{\Delta }(54)$ Flavor Symmetry with Triple Inverse Seesaw

    Hrishi Bora · Ng. K. Francis

    We present an extension of the $\Delta (54)$ flavor symmetry model by incorporating two Standard Model Higgs fields. We generated the neutrino mass matrices with the Triple Inverse Seesaw mechanism. Our numerical analysis reveals deviations from tribimaximal neutrino mixing resulting in a nonzero reactor angle (${\theta }_{13}$). The atmospheric oscillation parameter (${\theta }_{23}$) occupies the upper octant. The model predicts Normal Hierarchy (NH) for neutrino masses. The best-fit value is obtained with minimum ${\chi }^2$ analysis. The prediction of the modified model on CP-violating parameters, effective Majorana mass, and Neutrinoless double beta decay phenomenological investigations are found to be in congruous with the current neutrino oscillation data.

    hep-phInt.J.Mod.Phys.A(2024)·1 citation
12. 12*

    Quantum entanglement of ions for light dark matter detection

    Asuka Ito🇯🇵 · Ryuichiro Kitano🇯🇵 · Wakutaka Nakano🇯🇵 · Ryoto Takai🇯🇵

    A detection scheme is explored for light dark matter, such as axion dark matter or dark photon dark matter, using a Paul ion trap system. We first demonstrate that a qubit, constructed from the ground and first excited states of vibrational modes of ions in a Paul trap, can serve as an effective sensor for weak electric fields due to its resonant excitation. As a consequence, a Paul ion trap allows us to search for weak electric fields induced by light dark matter with masses around the neV range. Furthermore, we illustrate that an entangled qubit system involving $N$ ions can enhance the excitation rate by a factor of $N^2$. The sensitivities of the Paul ion trap system to axion-photon coupling and gauge kinetic mixing can reach previously unexplored parameter space.

    hep-phastro-ph.COhep-exquant-phJHEP(2024)·25 citations
13. 13*

    Axion dark matter (theory & experiment)

    Andreas Ringwald🇩🇪

    We review the motivation for the axion as a solution of the strong CP puzzle and as a candidate for cold dark matter. Then we discuss benchmark axion models and present their predictions concerning axion couplings to the Standard Model and axion dark matter abundance. Finally, we give an overview on the discovery potential of current and planned axion experiments, reaching from axion dark matter direct detection, over searches for solar axions, to direct production and detection of axions in the laboratory.

    hep-phPoS(2024)·4 citations
14. 14*

    Flipped SU(5): unification, proton decay, fermion masses and gravitational waves

    Stephen F. King🇬🇧 · George K. Leontaris🇬🇷 · Ye-Ling Zhou🇨🇳

    We study supersymmetric (SUSY) flipped $SU(5)\times U(1)$ unification, focussing on its predictions for proton decay, fermion masses and gravitational waves. We performed a two-loop renormalisation group analysis and showed that the SUSY flipped $SU(5)$ model predicts a high GUT scale $M_{\mathrm{GUT}}>10^{16}$ GeV. We also investigated the restrictions on the $M_{B-L}$ scale which is associated with the $U(1{)}_{\chi }$ breaking scale. We found that the $M_{B-L}$ scale can vary in a broad region with negligible or little effect on the value of $M_{\mathrm{GUT}}$. Proton decay in this model is induced by dimension-6 operators only. The dimension-5 operator induced by SUSY contribution is suppressed due to the missing partner mechanism. We found that the partial decay width $p\to {\pi }^0{e}^{+}$ is high suppressed, being at least one order of magnitude lower than the future Hyper-K sensitivity. We also studied fermion (including neutrino) masses and mixings which can also influence proton decay. We presented two scenarios of flavour textures to check the consistency of the results with fermion masses and mixing. The $B-L$ gauge breaking leads to the generation of cosmic strings. The $B-L$ scale here is not constrained by gauge coupling unification. If this scale is very close that of GUT breaking, strings can be unstable due to the decay to monopole-antimonople pair. Such metastable strings can be used to explain the NANOGrav signals of stochastic gravitational wave background, which may be interpreted here as resulting from the decay of metastable cosmic strings.

    hep-phJHEP(2024)·27 citations
15. 15*

    Neutrino Oscillations in Finite Time Path Out-of-Equilibrium Thermal Field Theory

    Ivan Dadić🇭🇷 · Dubravko Klabučar🇭🇷

    We demonstrate that the Finite-Time-Path Field Theory is an adequate tool for calculating neutrino oscillations. We apply this theory using a mass-mixing Lagrangian which involves the correct Dirac spin and chirality structure and a Pontecorvo-Maki-Nakagawa-Sakata (PMNS)-like mixing matrix. The model is exactly solvable. The Dyson-Schwinger equations transform propagators of the input free (massless) flavor neutrinos into a linear combination of oscillating (massive) neutrinos. The results are consistent with the predictions of the PMNS matrix while allowing for extrapolation to early times.

    hep-phSymmetry(2023)·2 citations
16. 16*

    Far-from-equilibrium attractors with Full Relativistic Boltzmann approach in boost-invariant and non-boost-invariant systems

    Vincenzo Nugara (1 and 2)🇮🇹 · Salvatore Plumari (1 and 2)🇮🇹 · Lucia Oliva (1 and 3)🇮🇹 · Vincenzo Greco (1 and 2) ((1) Department of Physics and Astronomy, University of Catania, Via S. Sofia 64, I-95125 Catania, (2) INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, I-95123 Catania, Italy, (3) INFN Sezione di Catania, Via S. Sofia 64, I-95123 Catania, Italy)🇮🇹

    We study the universal behavior associated with a Relativistic Boltzmann Transport (RBT) approach with the full collision integral in 0+1D conformal systems. We show that all momentum moments of the distribution function exhibit universal behavior. Furthermore, the RBT approach allows to calculate the full distribution function, showing that an attractor behavior is present in both the longitudinal and transverse momentum dependence. We compare our results to the far-from-equilibrium attractors determined with other approaches, such as kinetic theory in Relaxation Time Approximation (RTA) and relativistic hydrodynamic theories, both in their viscous (DNMR) an anisotropic (aHydro) formulations, finding a very similar evolution, but an even faster thermalization in RBT for higher order moments. For the first time, we extended this analysis also to study the attractor behavior under a temperature-dependent viscosity $\eta /s(T)$, accounting also for the rapid increase toward the hadronic phase. We find that a partial breaking of the scaling behavior with respect to $\tau /{\tau }_{eq}$ emerges only at $T\approx T_c$ generating a transient deviation from attractors; interestingly this in realistic finite systems may occur around the freeze-out dynamics. Finally, we investigate for the first time results beyond the boost-invariant picture, finding that also in such a case the system evolves toward the universal attractor. In particular, we present the forward and pull-back attractors at different space-time rapidities including rapidity regions where initially the distribution function is even vanishing.

    hep-phnucl-thEPJC(2024)·17 citations
17. 17*

    Inclusive Semileptonic $b\to c\ell \bar{\nu }$ Decays to Order $1/m_b^5$

    Thomas Mannel🇩🇪 · Ilija S. Milutin🇩🇪 · K. Keri Vos🇳🇱

    Inclusive semileptonic $B\to X_c\ell \bar{\nu }$ decays can be described in the Heavy Quark Expansion (HQE) and allow for a precision determination of the CKM element $|V_{cb}|$. We calculate the terms of $1/m_b^5$ and derive a ``trace formula'' which allows for the computation of the decay rate and kinematic moments of the spectrum up to this order in the HQE. We focus specifically on the reparametrization invariant (RPI) dilepton invariant mass $q^2$ moments of the spectrum, which depend on a reduced set of HQE parameters. At this order, ``intrinsic charm'' (IC) contributions proportional to $1/(m_b^3{m}_c^2)$ enter, which are numerically expected to be sizeable. Using the ``lowest-lying state saturation ansatz'' (LLSA), we estimate the size of these contributions. Within this approximation, we observe a partial cancellation between the IC and the ``genuine'' $1/m_b^5$ contributions, resulting in a small overall contribution.

    hep-phJHEP(2024)·20 citations
18. 18*

    Electron $g-2$ Foreshadowing Discoveries at FCC-ee

    Hooman Davoudiasl🇺🇸 · Pier Paolo Giardino🇪🇸

    A future $e^{+}{e}^{-}$ circular collider (FCC-ee) may provide a unique probe of the electron Yukawa coupling through Higgs boson production on resonance. Motivated by this exciting possibility, we examine a simple model which can result in $\mathcal{O}(10)$ modifications of the Higgs coupling to electrons. The model can also lead to deviations in the electron anomalous magnetic moment, $g_e-2$, which at present shows a $+2.2\sigma$ or $-3.7\sigma$ deviation, implied by differing precision determinations of the electromagnetic fine structure constant. The electron $g_e-2$ can be a forerunner for FCC-ee discoveries which, as we elucidate, may not be accessible to the high-luminosity LHC measurements. A simple extension of our model can also account for the current deviation in the muon $g_{\mu }-2$.

    hep-phhep-exPRD(2024)·12 citations
19. 19*

    Dense-matter equation of state at zero & finite temperature

    Alexander Clevinger🇺🇸 · Veronica Dexheimer🇺🇸 · Jeffrey Peterson🇺🇸

    At high density, matter is expected to undergo a phase transition to deconfined quark matter. Although the density at which it happens and the strength of the transition are still largely unknown, we can model it to be in agreement with known experimental data and reliable theoretical results. We discuss how deconfinement in dense matter can be affected by both by temperature and by strong magnetic fields within the CMF model. To explore different dependencies in our approach, we also explore how deconfinement can be affected by the assumption of different degrees of freedom, different vector coupling terms, and different deconfining potentials, all at zero temperature. Both zero-net-strangeness and isospin-symmetric heavy-ion collision matter and beta-equilibrated charge-neutral matter in neutron stars are discussed.

    ↳ nucl-thastro-ph.HEastro-ph.SRhep-phEPJ Web Conf.(2024)·0 citations
20. 20*

    La Physique Théorique des Hautes Energies en France

    Jean Iliopoulos🇫🇷

    The year 2023 marks three anniversaries: the 150th anniversary of the French Physical Society, the 100th anniversary since the publication of Louis de Broglie's articles (the first fundamental articles of Quantum Mechanics) and the 50th anniversary of the Standard Model, the theory which describes in a unified framework the strong, the electromagnetic and the weak interactions among elementary particles. This note is an attempt to present the situation of theoretical physics in France during these years and highlight the french contributions in this world effort. We shall see that, although these contributions have been important, french theorists rarely played the leading roles. At the end I will try to draw some conclusions from these findings.

    ↳ physics.hist-phhep-phhep-th0 citations
21. 21*

    Towards consistent nuclear interactions from chiral Lagrangians I: The path-integral approach

    Hermann Krebs🇩🇪 · Evgeny Epelbaum🇩🇪

    Low-energy nuclear interactions have been extensively studied in the framework of chiral effective field theory. The corresponding potentials have been worked out using dimensional regularization to evaluate ultraviolet divergent loop integrals. An additional cutoff is then introduced in the nuclear Schrödinger equation to calculate observables. Recently, we have shown that such a mixture of two regularization schemes violates chiral symmetry when applied beyond the two-nucleon system and/or to processes involving external probes. To solve this issue, three- and four-nucleon forces as well as exchange current operators need to be re-derived using symmetry-preserving cutoff regularization. While it is possible to introduce a symmetry-preserving cutoff already in the effective chiral Lagrangian, the appearance of high-order time derivatives of the pion field, caused by the regulator, makes the standard Hamiltonian-based methods not well suited for the calculation of nuclear potentials. Here, we propose a new approach to derive nuclear interactions using the path integral method with no reliance on the canonical quantization. To this aim, the interaction part of the action is brought to an instantaneous form via suitably chosen nonlocal field redefinitions. Loop contributions to the nuclear potentials are then generated through the functional determinant, induced by the field redefinitions. We discuss in detail the application of these ideas to the case of a regularized Yukawa-type model of pion-nucleon interactions. Our new method allows to perform a systematic quantum mechanical reduction within the quantum field theory framework and opens the way for deriving consistently regularized nuclear forces and current operators from the effective chiral Lagrangian.

    ↳ nucl-thhep-phhep-thPRC(2024)·26 citations
22. 22*

    Probing Low-Luminosity Gamma-Ray Emission from SNR G296.5+10.0 and CCO 1E 1207.4-5209 with CTAO

    Luana N. Padilha🇧🇷 · Rubens Jr. Costa🇧🇷 · Rita C. dos Anjos🇧🇷 · Jaziel G. Coelho🇧🇷

    The acceleration mechanisms of cosmic rays (CR) in supernova remnants (SNRs) and their associated compact central objects (CCOs) remain an open question in high-energy astrophysics. In this study, we perform a modeling of CR transport and gamma-ray emission from SNR G296.5+10.0 and its CCO 1E 1207.4-5209, using the latest public release of the GALPROP code (v57) and focusing, in particular, on the contribution from the CCO. Our simulations predict the contribution of CR from this source to the Galactic flux, accounting for energy losses and particle interaction processes. We find that, under time-evolving scenarios, the environment around SNR G296.5+10.0 and 1E 1207.4-5209 is suitable for CR acceleration and gamma-ray production. The analysis distinguishes between gamma rays produced by hadronic interactions in SNR G296.5+10.0 and by leptonic processes in CCO 1E 1207.4-5209, revealing that each mechanism dominates in different energy bands. We show that the Cherenkov Telescope Array Observatory (CTAO) can detect this emission with a significance of 5{\sigma} after 50 h of exposure, providing the first constraints on particle acceleration in this unique CCO-SNR system. These findings suggest that CCOs may be efficient electron accelerators, even in the absence of pulsar wind nebulae, and emphasize the critical role of next-generation observatories such as CTAO in unraveling CR acceleration processes in low-luminosity SNR-CCO systems.

    ↳ astro-ph.HEastro-ph.SRhep-phhep-thEPJC(2026)·0 citations
23. 23*

    PAIReD jet: A multi-pronged resonance tagging strategy across all Lorentz boosts

    Spandan Mondal🇺🇸 · Gaetano Barone🇺🇸 · Alexander Schmidt🇩🇪

    We propose a new approach of jet-based event reconstruction that aims to optimally exploit correlations between the products of a hadronic multi-pronged decay across all Lorentz boost regimes. The new approach utilizes clustered small-radius jets as seeds to define unconventional jets, referred to as PAIReD jets. The constituents of these jets are subsequently used as inputs to machine learning-based algorithms to identify the flavor content of the jet. We demonstrate that this approach achieves higher efficiencies in the reconstruction of signal events containing heavy-flavor jets compared to other event reconstruction strategies at all Lorentz boost regimes. Classifiers trained on PAIReD jets also have significantly better background rejections compared to those based on traditional event reconstruction approaches using small-radius jets at low Lorentz boost regimes. The combined effect of a higher signal reconstruction efficiency and better classification performance results in a two to four times stronger rejection of light-flavor jets compared to conventional strategies at low Lorentz-boosts, and rejection rates similar to classifiers based on large-radius multi-pronged jets at high Lorentz-boost regimes.

    ↳ hep-exhep-phJHEP(2024)·5 citations
24. 24*

    Accretion of the relativistic Vlasov gas onto a Kerr black hole

    Ping Li · Yong-Qiang Liu · Xiang-Hua Zhai🇨🇳

    We study the accretion of relativistic Vlasov gas onto a Kerr black hole, regarding the particles as distributed throughout all the space, other than just in the equatorial plane. We solve the relativistic Liouville equation in the full $3+1$ dimensional framework of Kerr geometry. For the flow that is stationary and axial symmetric, we prove that the distribution function is independent of the conjugate coordinates. For an explicit distribution that can approximate to Maxwell-Jüttner distribution, we further calculate the particle current density, the stress energy momentum tensor and the unit accretion rates of mass, energy and angular momentum. The analytic results at large distance are shown to be consistent with the limits of the numerical ones computed at finite distance. Especially, we show that the unit mass accretion rate agrees with the Schwarzschild result in the case of low temperature limit. Furthermore, we find from the numerical results that the three unit accretion rates vary with the angle in Kerr metric and the accretion of Vlasov gas would slow down the Kerr black hole. The closer to the equator, the faster it slows down the black hole.

    ↳ gr-qcastro-ph.HEhep-phPRD(2023)·13 citations
25. 25*

    New limits on the local Lorentz invariance violation of gravity in the Standard-Model Extension with pulsars

    Yiming Dong🇨🇳 · Ziming Wang🇨🇳 · Lijing Shao🇨🇳

    Lorentz Violation (LV) is posited as a possible relic effect of quantum gravity at low energy scales. The Standard-Model Extension provides an effective field-theoretic framework for examining possible deviations attributed to LV. With their high observational accuracy, pulsars serve as ideal laboratories for probing LV. In the presence of LV, both the spin precession of solitary pulsars and orbital dynamics of binary pulsars would undergo modifications. Observations of pulse profiles and times of arrival (TOAs) of pulses allow for an in-depth investigation of these effects, leading to the establishment of strict limits on LV coefficients. We revisit the project of limiting local LV with updated pulsar observations. We employ a new parameter estimation method and utilize state-of-the-art pulsar timing observation data and get new limits on 8 linear combinations of LV coefficients based on 25 tests from 12 different systems. Compared to previous limits from pulsars, precision has improved by a factor of two to three. Additionally, we explore prospects for further improvements from pulsars. Simulation results indicate that more observations of spin precession in solitary millisecond pulsars could significantly enhance the accuracy of spatial LV coefficients, potentially by three to four orders of magnitude. As observational data accumulate, pulsars are anticipated to increasingly contribute to the tests of LV.

    ↳ astro-ph.HEgr-qchep-phPRD(2024)·10 citations
26. 26*

    Vortices, topology and time

    Altay Etkin🇬🇧 · João Magueijo🇬🇧 · Farbod-Sayyed Rassouli🇬🇧

    We relate physical time with the topology of magnetic field vortices. We base ourselves on a formulation of unimodular gravity where the cosmological constant $\Lambda$ appears as the canonical dual to a variable which on-shell becomes four-volume time. If the theory is restricted to a topological axionic form (viz. a parity-odd product of an electric and a magnetic field), such a time variable becomes the spatial integral of the Chern-Simons density. The latter equates to helicity, so that unimodular time is transmuted into the linking number of the vortices of the topological magnetic field, times their flux. With the added {\it postulate} that this flux is a universal constant, the flow of time can thus be interpreted as the progressive weaving of further links between magnetic field vortices, each link providing a quantum of time with value related to the fixed flux. Non-abelian extensions, and targetting parameters other than $\Lambda$ are briefly examined, exposing different types of vortices and a possible role for inter-linking leading to new phenomenology.

    ↳ hep-thgr-qchep-phPLB(2024)·4 citations
27. 27*

    Rapidity scan approach for net-baryon cumulants with a statistical thermal model

    Jianing Li🇨🇳 · Lipei Du🇨🇦 · Shuzhe Shi🇨🇳

    Utilizing rapidity-dependent measurements to map the QCD phase diagram provides a complementary approach to traditional beam-energy-dependent measurements around midrapidity. The changing nature of thermodynamic properties of QCD matter along the beam axis in heavy-ion collisions at low collision energies both motivates and poses challenges for this method. In this study, we derive the analytical cumulant-generating function for subsystems within distinct rapidity windows, while accounting for global net-baryon charge conservation of the full system. Rapidity-dependent net-baryon cumulants are then calculated for a system exhibiting inhomogeneity along the beam axis, and their sensitivity to finite acceptances through changing rapidity bin widths is explored. We highlight the nontrivial behaviors exhibited by these cumulants, underscoring their importance in establishing a noncritical baseline for interpreting net-proton cumulants in the search for the QCD critical point. Finally, we discuss the implications of the rapidity scan for mapping the QCD phase diagram within the current context.

    ↳ nucl-thhep-phnucl-exPRC(2024)·7 citations
28. 28*

    Dark Matter Subhalo Evaporation by Coulomb-like Interaction with Galactic Gas

    Yugen Lin🇨🇳 · Yu Gao🇨🇳

    Coulomb-like interactions typically has a cross section scales with velocity dependence as $\sigma ={\sigma }_0{v}^{-4}$. The momentum transfer rate between a slightly charged dark matter and ionized particles increases significantly at low velocity, and it produces prominent evaporation effects on small-sized dark matter overdensities. We show that when subhalos encounter the hot gases near the Milky Way's disc, their survival can place stringent limits on Coulomb-like scattering strength. For $M<10^5{M}_{\odot }$ subhalos to survive a kilo-parsec distance from the galactic center, with a dark matter mass in the sub-GeV range, the evaporation limit becomes one order of magnitude stronger than the limits from current cosmic microwave background and baryon acoustic oscillation data. We also interpret our bounds into the electron-recoil direct detection cross section, and show that the evaporation effect can lead to a stronger constraint on Coulomb-like interaction for sub-MeV dark matter in comparison with direct detection experiments.

    ↳ astro-ph.COhep-phCPC(2026)·5 citations
29. 29*

    Shakhov-type extension of the relaxation time approximation in relativistic kinetic theory and second-order fluid dynamics

    Victor E. Ambruş🇷🇴 · Etele Molnár🇵🇱

    We present a relativistic Shakhov-type generalization of the Anderson-Witting relaxation time model for the Boltzmann collision integral to modify the ratio of momentum diffusivity to thermal diffusivity. This is achieved by modifying the path on which the single particle distribution function $f_{\mathbf{k}}$ approaches local equilibrium $f_{0\mathbf{k}}$ by constructing an intermediate Shakhov-type distribution $f_{\mathrm{S}\mathbf{k}}$ similar to the 14-moment approximation of Israel and Stewart. We illustrate the effectiveness of this model in case of the Bjorken expansion of an ideal gas of massive particles and the damping of longitudinal waves through an ultrarelativistic ideal gas.

    ↳ nucl-thhep-phphysics.flu-dynPLB(2024)·4 citations
30. 30*

    Tidal Love numbers of Axion stars

    Jun-Ru Chen🇨🇳 · Shi-Xian Sun · Long-Xing Huang🇨🇳 · Yong-Qiang Wang🇨🇳

    We investigate the tidal deformability of spherically symmetric axion stars on the stable branches, including the Newtonian and relativistic branches. The results suggest that on the stable branch, the electric Love numbers of axion star are positive, while the magnetic Love numbers are negative. On the Newtonian stable branch, the electric tidal Love numbers are much larger than the magnetic ones, while on the relativistic stable branch, they are slightly larger. Furthermore, the relativistic stable branch has much smaller tidal Love numbers than the Newtonian stable branch, indicating weaker deformability of axion stars on the relativistic stable branch. This could be attributed to the fact that on the relativistic branch, axion stars are more compact, resulting hardly distorted by tidal forces.

    ↳ gr-qchep-phhep-thPRD(2024)·10 citations
31. 31*

    Phonon dynamics for light dark matter detection

    Martí Raya-Moreno🇪🇸 · Bradley J. Kavanagh🇪🇸 · Lourdes Fàbrega🇪🇸 · Riccardo Rurali🇪🇸

    The search for low-mass dark matter (DM) goes in parallel with the identification of new detection channels and the development of suitable detectors. Detection of the resulting small energy depositions is challenging: it requires extremely high sensitivity, only achievable by cryogenic thermal detectors, which might be put to the limit. Understanding the processes which can limit performances of these detectors can be thus crucial for evaluating the feasibility of the proposed new detection schemes and to design the detectors and tune their performance. In this paper we focus on a promising detection scheme, the excitation of single optical phonons in polar materials, to evaluate one of the possible limiting factors of cryogenic thermal detectors, i.e. the phonon dynamics in the target/absorber. We present a detailed theoretical analysis, within an entirely ab initio scheme, of the downconversion and propagation processes undergone by optical phonons, created by the interaction of a low-mass DM particle in an Al2O3 target, until they reach the interface with a phonon Al collector. After a preliminary methodological survey that reveals the limitations of any Relaxation Time Approximation based method, we developed a 3D beyond-RTA phonon Monte Carlo that allowed us to introduce the spatial dimension of the device and address questions about impact of target size and scattering position. We analyse also the effect of the phonon energy and wavevector and show that isotopes can, perhaps counterintuitively, result in a larger heat flux by providing transport channels of higher velocities, thus favoring detection. Our results suggest that, though challenging, the direct detection of light DM via athermal phonon generation appears feasible, and that the phonon downconversion followed by quasi-ballistic propagation does not appear to be a major bottleneck in terms of reducing the signal.

    ↳ cond-mat.mtrl-scihep-phPRD(2024)·6 citations
32. 32*

    Neutrino fast flavor oscillations with moments: linear stability analysis and application to neutron star mergers

    Julien Froustey🇺🇸 · Sherwood Richers🇺🇸 · Evan Grohs🇺🇸 · Samuel Flynn🇺🇸 · Francois Foucart🇺🇸 · James P. Kneller🇺🇸 · Gail C. McLaughlin🇺🇸

    Providing an accurate modeling of neutrino physics in dense astrophysical environments such as binary neutron star mergers presents a challenge for hydrodynamic simulations. Nevertheless, understanding how flavor transformation can occur and affect the dynamics, the mass ejection, and the nucleosynthesis will need to be achieved in the future. Computationally expensive, large-scale simulations frequently evolve the first classical angular moments of the neutrino distributions. By promoting these quantities to matrices in flavor space, we develop a linear stability analysis of fast flavor oscillations using only the first two "quantum" moments, which notably requires generalizing the classical closure relations that appropriately truncate the hierarchy of moment equations in order to treat quantum flavor coherence. After showing the efficiency of this method on a well-understood test situation, we perform a systematic search of the occurrence of fast flavor instabilities in a neutron star merger simulation. We discuss the successes and shortcomings of moment linear stability analysis, as this framework provides a time-efficient way to design and study better closure prescriptions in the future.

    ↳ astro-ph.HEhep-phPRD(2024)·46 citations
33. 33*

    A gamma-ray study of galactic PeVatron candidates LHAASO J1825-1326 and LHAASO J1839-0545

    Rubens Jr. Costa🇧🇷 · Débora B. Götz🇧🇷 · Rita C. Anjos🇧🇷 · Luiz. A. Stuani Pereira🇧🇷 · Alexandre J. T. S. Mello🇧🇷

    Recent studies by LHAASO have shown the presence of high-luminosity PeVatrons in our Galaxy. We examine two notable sources, each consisting of two pulsars, detected by LHAASO. We study gamma and cosmic-ray emissions from the surroundings of these pulsars. We used the Gammapy software to perform gamma-ray measurements from these sources in anticipation of future analyses to be carried out with the CTAO, which is now under development. Furthermore, the particle propagation throughout the Galaxy was simulated using the GALPROP software, accounting for emission from energy losses due to spin-down. As a result, we present the particle spectra generated during this propagation phase along with the corresponding gamma-ray emission. The findings suggest that CTAO may have the capability to detect these sources and show that the data can be explained by gamma rays coming from a leptonic model.

    ↳ astro-ph.HEastro-ph.SRhep-phhep-thJCAP(2024)·8 citations
34. 34*

    Gravitational wave populations and cosmology with neural posterior estimation

    Konstantin Leyde🇫🇷 · Stephen R. Green🇬🇧 · Alexandre Toubiana🇩🇪 · Jonathan Gair🇩🇪

    We apply neural posterior estimation for fast-and-accurate hierarchical Bayesian inference of gravitational wave populations. We use a normalizing flow to estimate directly the population hyper-parameters from a collection of individual source observations. This approach provides complete freedom in event representation, automatic inclusion of selection effects, and (in contrast to likelihood estimation) without the need for stochastic samplers to obtain posterior samples. Since the number of events may be unknown when the network is trained, we split into sub-population analyses that we later recombine; this allows for fast sequential analyses as additional events are observed. We demonstrate our method on a toy problem of dark siren cosmology, and show that inference takes just a few minutes and scales to $\sim 600$ events before performance degrades. We argue that neural posterior estimation therefore represents a promising avenue for population inference with large numbers of events.

    ↳ gr-qcastro-ph.COhep-phPRD(2024)·51 citations
35. 35*

    Exact Schwinger Proper Time Renormalisation

    Steven Abel🇬🇧 · Lucien Heurtier🇬🇧

    We derive an exact version of the Schwinger Proper Time Renormalisation Group flow equation from first principles from the complete path integral, without using any perturbative expansion. We study the advantages of this flow equation as compared to the canonical Exact Renormalisation Group flow equation, which uses a regulator in momentum space. We use our flow equation to recover the convexity of the effective scalar potential in the IR limit and apply it to the study of false-vacuum decay.

    ↳ hep-thhep-phJHEP(2025)·11 citations
36. 36*

    2023 Update of ${\epsilon }_K$ with lattice QCD inputs

    Seungyeob Jwa🇰🇷 · Jeehun Kim🇰🇷 · Sunghee Kim🇰🇷 · Sunkyu Lee🇰🇷 · Weonjong Lee · Jaehoon Leem🇰🇷 · Jeonghwan Pak🇰🇷 · Sungwoo Park🇺🇸

    We report recent progress on ${\epsilon }_K$ evaluated directly from the standard model (SM) with lattice QCD inputs such as ${\hat{B}}_K$, $|V_{cb}|$, $|V_{us}|$, $|V_{ud}|$, ${\xi }_0$, ${\xi }_2$, ${\xi }_{\text{LD}}$, $f_K$, and $m_c$. We find that the standard model with exclusive $|V_{cb}|$ and lattice QCD inputs describes only 66\% of the experimental value of $|{\epsilon }_K|$ and does not explain its remaining 34\%, which corresponds to a strong tension in $|{\epsilon }_K|$ at the $4.9\sigma \sim 3.9\sigma$ level between the SM theory and experiment. We also find that this tension disappears when we use the inclusive value of $|V_{cb}|$ obtained using the heavy quark expansion based on the QCD sum rule approach.

    ↳ hep-lathep-phPoS(2024)·7 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.