Mon·Jul 17, 2023Monday·July 17, 2023

1. 01*

   ${\tau }_{B_s}/{\tau }_{B_d}$ and $\Delta {\Gamma }_s$ confront new physics in $b\to s\tau \tau$

   Marzia Bordone🇨🇭 · Mario Fernández Navarro🇬🇧

   Several new physics scenarios that address anomalies in $B$-physics predict an enhancement of $b\to s\tau \tau$ with respect to its Standard Model prediction. Such scenarios necessarily imply modifications of the lifetime ratio ${\tau }_{B_s}/{\tau }_{B_d}$ and the lifetime difference $\Delta {\Gamma }_s$. In this work, we explore indirect bounds provided by these observables over new physics scenarios. We also estimate future projections, showing that future experimental and theoretical improvements on both ${\tau }_{B_s}/{\tau }_{B_d}$ and $\Delta {\Gamma }_s$ have the potential to provide bounds competitive with those directly extracted from $b\to s\tau \tau$ transitions. After performing a model-independent analysis, we apply our results to the particular case of leptoquark mediators proposed to address the $R_{D^{(\ast )}}$ anomalies.

   hep-phhep-exEPJC(2023)·10 citations
2. 02*

   PRyMordial: The First Three Minutes, Within and Beyond the Standard Model

   Anne-Katherine Burns🇺🇸 · Tim M.P. Tait🇺🇸 · Mauro Valli🇮🇹

   In this work we present PRyMordial: A package dedicated to efficient computations of observables in the Early Universe with the focus on the cosmological era of Big Bang Nucleosynthesis (BBN). The code offers fast and precise evaluation of BBN light-element abundances together with the effective number of relativistic degrees of freedom, including non-instantaneous decoupling effects. PRyMordial is suitable for state-of-the-art analyses in the Standard Model as well as for general investigations into New Physics active during BBN. After reviewing the physics implemented in PRyMordial, we provide a short guide on how to use the code for applications in the Standard Model and beyond. The package is written in Python, but more advanced users can optionally take advantage of the open-source community for Julia. PRyMordial is publicly available on GitHub.

   hep-phastro-ph.COnucl-thEPJC(2024)·85 citations
3. 03*

   A Monte Carlo study of multiplicity fluctuations in proton-proton collisions at $\sqrt{s}=$~7~TeV

   Valeria Zelina Reyna Ortiz🇵🇱 · Maciej Rybczynski🇵🇱 · Zbigniew Wlodarczyk🇵🇱

   With large volumes of data available at LHC, it has possible to study the multiplicity distributions. It is interesting as well to check how well event generators can describes the properties and the behavior of multi-particle production processes. In this paper, we analyse the oscillatory behavior of modified combinants in proton-proton collisions at centre of mass energy of 7 TeV.

   hep-phPRD(2023)·2 citations
4. 04*

   Probing new physics with polarized $\tau$ and ${\Lambda }_c$ in quasielastic ${\nu }_{\tau }+n\to {\tau }^{-}+{\Lambda }_c$ scattering process

   Ya-Ru Kong🇨🇳 · Li-Fen Lai🇨🇳 · Xin-Qiang Li🇨🇳 · Xin-Shuai Yan🇨🇳 · Ya-Dong Yang🇨🇳 · Dong-Hui Zheng🇨🇳

   The absence of semitauonic decays of charmed hadrons makes the decay processes mediated by the quark-level $c\to d{\tau }^{+}{\nu }_{\tau }$ transition inadequate for probing a generic new physics (NP) with all kinds of Dirac structures. To fill in this gap, we consider in this paper the quasielastic neutrino scattering process ${\nu }_{\tau }+n\to {\tau }^{-}+{\Lambda }_c$, and propose searching for NP through the polarizations of the $\tau$ lepton and the ${\Lambda }_c$ baryon. In the framework of a general low-energy effective Lagrangian, we perform a comprehensive analysis of the (differential) cross sections and polarization vectors of the process both within the Standard Model and in various NP scenarios, and scrutinize possible NP signals. We also explore the influence on our findings due to the uncertainties and the different parametrizations of the ${\Lambda }_c\to N$ transition form factors, and show that they have become one of the major challenges to further constrain possible NP through the quasielastic scattering process.

   hep-phPRD(2023)·5 citations
5. 05*

   Analysis of the higher twist GTMD $F_{31}$ for proton in the light-front quark-diquark model

   Shubham Sharma🇮🇳 · Harleen Dahiya🇮🇳

   In the light-front quark-diquark model (LFQDM), the higher twist generalized transverse momentum dependent distribution (GTMD) $F_{31}(x,{\mathbf{p}}_{\perp },{\mathbf{\Delta }}_{\perp })$ for the proton has been analyzed. We have derived the GTMD overlap equation by the analysis of GTMD correlator, employing the light-front wave functions in both the scalar and vector diquark situations. With the relevant 2-D and 3-D figures, the behavior of GTMD $F_{31}(x,{\mathbf{p}}_{\perp },{\mathbf{\Delta }}_{\perp })$ with variations in its variables has been illustrated. Further, on applying the transverse momentum dependent distribution (TMD) limit on GTMD $F_{31}(x,{\mathbf{p}}_{\perp },{\mathbf{\Delta }}_{\perp })$, the expression of TMD $f_3(x,{\mathbf{p}}_{\perp })$ has been obtained.

   hep-ph2 citations
6. 06*

   GENEVA Monte Carlo: status and new developments

   Giulia Marinelli🇮🇹

   We review GENEVA Monte Carlo framework, that combines three theoretical tools used for QCD precise predictions into a single structure. In this talk we highlight its main features, discussing some new improvements involving both colour singlet productions, as well as for the production of final states with heavy coloured partons and jets.

   hep-ph0 citations
7. 07*

   Charm-Meson $t$-channel Singularities in an Expanding Hadron Gas

   Eric Braaten🇺🇸 · Roberto Bruschini🇺🇸 · Li-Ping He🇩🇪 · Kevin Ingles🇺🇸 · Jun Jiang🇨🇳

   We study the time evolution of the numbers of charm mesons after the kinetic freezeout of the expanding hadron gas produced by the hadronization of the quark-gluon plasma from a central heavy-ion collision. The $\pi D$ reaction rates have contributions from a $D^{\ast }$ resonance in the $s$ channel. The $\pi D^{\ast }$ reaction rates are enhanced by $t$-channel singularities from an intermediate $D$. The contributions to reaction rates from $D^{\ast }$ resonances and $D$-meson $t$-channel singularities are sensitive to thermal mass shifts and thermal widths. In the expanding hadron gas, the $t$-channel singularities are regularized by the thermal $D$ widths. After kinetic freezeout, the thermal $D$ widths are dominated by coherent pion forward scattering. The contributions to $\pi D^{\ast }$ reaction rates from $t$-channel singularities are inversely proportional to the pion number density, which decreases to 0 as the hadron gas expands. The $t$-channel singularities produce small but significant changes in charm-meson ratios from those predicted using the known $D^{\ast }$-decay branching fractions.

   hep-phPRD(2023)·6 citations
8. 08*

   Low-Scale Leptogenesis with Low-Energy Dirac CP-Violation

   Alessandro Granelli🇮🇹 · Silvia Pascoli🇮🇹 · Serguey T. Petcov🇮🇹

   We study the freeze-in scenario of leptogenesis via oscillations within the type-I seesaw model with two quasi-degenerate heavy Majorana neutrinos $N_{1,2}$ having masses $M_2>M_1\sim (0.1-100)\text{GeV}$, $(M_2-M_1)/M_1\ll 1$, focusing on the role of the CP-violation provided by the Dirac phase $\delta$ of the Pontecorvo-Maki-Nakagawa-Sakata lepton mixing matrix. We find that viable leptogenesis can be due solely to CP-violating values of $\delta$ and that the $N_{1,2}$ total mixing squared ${\Theta }^2={\sum }_{\alpha }{\Theta }_{\alpha }^2$ needed is within the reach of future experiments, ${\Theta }_{\alpha }$ parameterising the coupling to the charged lepton $\alpha =e,\mu ,\tau$. Furthermore, the required parameter space differs from that associated with additional Casas-Ibarra sources of CP-violation. Future determination of $\delta$, ${\Theta }^2$ and/or the ratios ${\Theta }_{\tau }^2:{\Theta }_{\mu }^2:{\Theta }_e^2$ would provide a critical test of the considered scenario.

   hep-phPRD(2023)·14 citations
9. 09*

   NNLL Resummation for Projected Three-Point Energy Correlator

   Wen Chen🇨🇳 · Jun Gao🇺🇸 · Yibei Li🇨🇳 · Zhen Xu🇨🇳 · Xiaoyuan Zhang🇺🇸 · Hua Xing Zhu🇨🇳

   The projected energy correlator measures the energy deposited in multiple detectors as a function of the largest angular distance $x_L=(1-\cos {\chi }_L)/2$ between detectors. The collinear limit $x_L\to 0$ of the projected energy correlator is particularly interesting for understanding the jet-substructures, while the large logarithms of $x_L$ could potentially spoil the perturbation theory and must be resummed. As a necessary ingredient for its resummation at next-to-next-to-leading logarithmic (NNLL) accuracy, we calculate the two-loop jet functions for the projected three-point energy correlator (E3C), using direct integration method and the parameter space Integration-by-Part (IBP) method. We then present the NNLL resummation for $e^{+}{e}^{-}$ annihilation and an approximate NNLL resummation for $pp\to jj$ process, where the two-loop hard constant is estimated in the latter case. The convergence is improved and the hadronization effect in the collinear limit is suppressed when considering the ratio of E3C distribution to two-point energy-energy correlator (EEC). Our results show potential in precision determination of strong coupling constant using energy correlators from both $e^{+}{e}^{-}$ data and $pp$ data.

   hep-phhep-exJHEP(2024)·67 citations
10. 10*

    Fits to measurements of rare heavy flavour decays

    Ben Allanach (University of Cambridge)🇬🇧

    This write-up is intended to form part of the proceedings for Lepton-Photon 2023. We review the decays $b\to c\ell {\bar{\nu }}_{\ell }$ (where $\ell \in \{e,\mu ,\tau \}$) as well as $b\to s{\mu }^{+}{\mu }^{-}$ and $b\to s{e}^{+}{e}^{-}$, giving the current state-of-the-art in terms of measurements. We review fits to such data of new physics weak effective field theory operators, before closing with interpretations in terms of simplified TeV-scale field theories.

    hep-ph4 citations
11. 11*

    Primordial non-Gaussianity as a probe of seesaw and leptogenesis

    Chee Sheng Fong🇧🇷 · Anish Ghoshal🇵🇱 · Abhishek Naskar🇮🇳 · Moinul Hossain Rahat🇬🇧 · Shaikh Saad🇨🇭

    We present the possibility that the seesaw mechanism and nonthermal leptogenesis can be {investigated} via primordial non-Gaussianities in the context of a majoron curvaton model. Originating as a massless Nambu-Goldstone boson from the spontaneous breaking of the global baryon ($B$) minus lepton ($L$) number symmetry at a scale $v_{B-L}$, majoron becomes massive when it couples to a new confining sector through anomaly. Acting as a curvaton, majoron produces the observed red-tilted curvature power spectrum without relying on any inflaton contribution, and its decay in the post-inflationary era gives rise to a nonthermal population of right-handed neutrinos that participate in leptogenesis. A distinctive feature of the mechanism is the generation of observable non-Gaussianity, {in the parameter space where the red-tilted power spectrum and sufficient baryon asymmetry are produced.} We {find} that the non-Gaussianity parameter $f_{\mathrm{NL}}\gtrsim \mathcal{O}(0.1)$ is produced for high-scale seesaw ($v_{B-L}$ at $\mathcal{O}(10^{14-17})$ GeV) and leptogenesis ($M_1\gtrsim \mathcal{O}(10^6)$ GeV) where the latter represents the lightest right-handed neutrino mass. While the current bounds on local non-Gaussianity excludes some part of parameter space, the rest can be fully probed by future experiments like CMB-S4, LSST, and 21 cm tomography.

    hep-phastro-ph.COhep-thJHEP(2023)·8 citations
12. 12*

    Parker Bounds on Monopoles with Arbitrary Charge from Galactic and Primordial Magnetic Fields

    Takeshi Kobayashi🇮🇹 · Daniele Perri🇮🇹

    We present a comprehensive study of Parker-type bounds on magnetic monopoles with arbitrary magnetic charge, including minicharged monopoles and magnetic black holes. We derive the bounds based on the survival of galactic magnetic fields, seed magnetic fields, as well as primordial magnetic fields. We find that monopoles with different magnetic charges are best constrained by different astrophysical systems: while monopoles with a Dirac charge are tightly constrained by seed galactic magnetic fields, minicharged monopoles are strongly constrained by primordial magnetic fields, and magnetic black holes by the density of dark matter. We also assess the viability of the various types of monopoles as dark matter, by studying whether they can cluster with galaxies hosting magnetic fields.

    hep-phastro-ph.COgr-qchep-thPRD(2023)·24 citations
13. 13*

    Dark matter detection using nuclear magnetization in magnet with hyperfine interaction

    So Chigusa🇺🇸 · Takeo Moroi🇯🇵 · Kazunori Nakayama🇯🇵 · Thanaporn Sichanugrist🇯🇵

    We consider the possibility to detect cosmic light dark matter (DM), i.e., axions and dark photons, of mass $\sim 10^{-6}$ eV and $\sim 10^{-4}$ eV, by magnetic excitation in a magnet with strong hyperfine interaction. In particular, we consider a canted anti-ferromagnet, MnCO${}_3$, as a concrete candidate material. With spin transfer between nuclear and electron spins allowed by the hyperfine interaction, nuclear spins become naturally highly polarized due to an effective (electron-spin-induced) magnetic field, and have long-range interactions with each other. The collective precession of nuclear spins, i.e., a nuclear magnon, can be generated by the DM field through the nucleon-DM interaction, while they are also sensitive to the electron-DM interaction through the electron-nuclear spin mixing. Compared with conventional nuclear-spin precession experiments, this system as a DM sensor is sensitive to higher frequency needing only a small static magnetic field applied. The system also has collective precession of electron spins, mixed with nuclear spins, as the additional channels that can be used for DM probes. We estimate the sensitivity under appropriate readout setups such as an inductive pick-up loop associated with an LC resonant circuit, or a photon cavity with a photon counting device. We show that this method covers an unexplored parameter region of light bosonic DM.

    hep-phcond-mat.mes-hallhep-exquant-phPRD(2023)·18 citations
14. 14*

    Laser-driven lepton polarization in the quantum radiation-dominated reflection regime

    Kai-Hong Zhuang🇨🇳 · Yue-Yue Chen🇨🇳 · Yan-Fei Li🇨🇳 · Karen Z. Hatsagortsyan🇩🇪 · Christoph H. Keitel🇩🇪

    Generation of ultrarelativistic polarized leptons during interaction of an ultrarelativistic electron beam with a counterpropagating ultraintense laser pulse is investigated in the quantum radiation-dominated domain. While the symmetry of the laser field tends to average the radiative polarization of leptons to zero, we demonstrate the feasibility of sizable radiative polarization through breaking the symmetry of the process in the reflection regime. After the reflection, the off-axis particles escape the tightly focused beam with polarization correlated to the emission angle, while the particles at the beam center are more likely to be captured in the laser field with unmatched polarization and kinetic motion. Meanwhile, polarization along the electric field emerges due to the spin rotation in the transverse plane via precession. In this way, the combined effects of radiative polarization, spin precession and the laser field focusing are shaping the angle-dependent polarization for outgoing leptons. Our spin-resolved Monte Carlo simulations demonstrate an angle-dependent polarization degree up to $\sim 20\%$ for both electrons and positrons, with a yield of one pair per seed electron. It provides a new approach for producing polarized high density electron and positron jets at ultraintense laser facilities.

    hep-phPRD(2023)·14 citations
15. 15*

    Emergent symmetries of relativistic fluid dynamics from local ergodicity

    Giorgio Torrieri🇧🇷

    We show that volume-preserving diffomorphisms and the chemical shift symmetry defining relativistic lagrangian ideal fluid dynamics can be derived as an emerging symmetry when ergodicity is assumed to apply locally in a way that is invariant under smooth spacetime foliations. This can be used as a way to derive the ideal hydrodynamic limit in a strongly coupled but strongly fluctuating medium. We comment on the connection with thermalization in small systems, the Eigenstate thermalization hypothesis and deviations from the ideal limit.

    ↳ hep-thgr-qchep-phnucl-thPRD(2024)·15 citations
16. 16*

    Reexamine the dark matter scenario accounting for the positron excess in a new cosmic ray propagation model

    Xing-Jian Lv🇨🇳 · Xiao-Jun Bi🇨🇳 · Kun Fang🇨🇳 · Peng-Fei Yin🇨🇳 · Meng-Jie Zhao🇨🇳

    The positron excess in cosmic rays has stimulated a lot of interests in the last decade. The dark matter origin of the extra positrons has attracted great attention. However, the $\gamma$-ray search set very stringent constraints on the dark matter annihilation/decay rate, which leads to great disfavor of the dark matter scenario. In the work, we incorporate the recent progress in cosmic rays propagation and reexamine the dark matter scenario accounting for the positron excess. Recent observations indicate that cosmic rays propagation in the Milky Way may be not uniform and diffusion in the Galactic disk should be slower than that in the halo. In the spatial-dependent propagation model, the positrons/electrons are more concentrated in the disk and lead to smaller dark matter annihilation/decay rate to account for the positron excess and also a smaller deficit in the background positron flux. Especially for the ${\mu }^{+}{\mu }^{-}$ channel the positron spectrum fit the AMS-02 latest data perfectly and the annihilation rate satisfies all the present constraints from $\gamma$-ray and CMB observations.

    ↳ astro-ph.HEhep-phPRD(2024)·2 citations
17. 17*

    Robust bounds on ALP dark matter from dwarf spheroidal galaxies in the optical MUSE-Faint survey

    Elisa Todarello🇮🇹 · Marco Regis🇮🇹 · Javier Reynoso-Cordova🇮🇹 · Marco Taoso🇮🇹 · Daniel Vaz🇵🇹 · Jarle Brinchmann🇵🇹 · Matthias Steinmetz🇩🇪 · Sebastiaan L. Zoutendijk🇳🇱

    Nearby dwarf spheroidal galaxies are ideal targets in the search for indirect dark matter (DM) signals. In this work, we analyze MUSE spectroscopic observations of a sample of five galaxies, composed of both classical and ultra-faint dwarf spheroidals. The goal is to search for radiative decays of axion-like particles (ALPs) in the mass range of 2.7-5.3 eV. After taking into account the uncertainties associated with the DM spatial distribution in the galaxies, we derive robust bounds on the effective ALP-two-photon coupling. They lie well below the QCD axion band and are significantly more constraining than limits from other probes, in the relevant mass range. We also test the possible presence of a positive signal, concluding that none of the channels selected for this analysis, i.e., not affected by large background contamination, is exhibiting such evidence.

    ↳ astro-ph.COhep-phJCAP(2024)·55 citations
18. 18*

    Prescaling relaxation to nonthermal attractors

    Michal P. Heller🇧🇪 · Aleksas Mazeliauskas🇩🇪 · Thimo Preis🇩🇪

    We study how isotropic and homogeneous far-from-equilibrium quantum systems relax to nonthermal attractors, which are of interest for cold atoms and nuclear collisions. We demonstrate that a first-order ordinary differential equation governs the self-similar approach to nonthermal attractors, i.e., the prescaling. We also show that certain natural scaling-breaking terms induce logarithmically slow corrections that prevent the scaling exponents from reaching the constant values during the system's lifetime. We propose that, analogously to hydrodynamic attractors, the appropriate mathematical structure to describe such dynamics is the transseries. We verify our analytic predictions with state-of-the-art 2PI simulations of the large-N vector model and QCD kinetic theory.

    ↳ hep-thcond-mat.quant-gashep-phnucl-thPRL(2024)·23 citations
19. 19*

    Searching for additional Higgs bosons at ATLAS

    Anna Kaczmarska🇵🇱

    Extending the Higgs sector by introducing additional scalar fields to account for the electroweak symmetry breaking, can provide solutions to some of the questions the Standard Model fails to answer. Introducing additional scalar fields leads to extra Higgs like particles, which can be either neutral or charged. These proceedings present some recent direct searches for additional Higgs bosons, using proton proton collision data at 13 TeV collected by the ATLAS experiment in Run 2 of the LHC.

    ↳ hep-exhep-ph0 citations
20. 20*

    FAST pulsar database: I. Polarization profiles of 682 pulsars

    P. F. Wang🇨🇳 · J. L. Han🇨🇳 · J. Xu🇨🇳 · C. Wang🇨🇳 · Y. Yan🇹🇭 · W. C. Jing · W. Q. Su · D. J. Zhou · T. Wang🇨🇳

    Pulsar polarization profiles are very basic database for understanding the emission processes in pulsar magnetosphere. After careful polarization calibration of the 19-beam L-band receiver and verification of beam-offset observation results, we obtain polarization profiles of 682 pulsars from observations by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) during the survey tests for the Galactic Plan Pulsar Snapshot (GPPS) survey and other normal FAST projects. Among them, polarization profiles of about 460 pulsars are observed for the first time. The profiles exhibit diverse features. Some pulsars have a polarization position angle curve with a good S-shaped swing, and some with orthogonal modes; some have components with highly linearly components or strong circularly polarized components; some have a very wide profile, coming from an aligned rotator, and some have an interpulse from a perpendicular rotator; some wide profiles are caused by interstellar scattering. We derive geometry parameters for 190 pulsars from the S-shaped position angle curves or with orthogonal modes. We find that the linear and circular polarization or the widths of pulse profiles have various frequency dependencies. Pulsars with large fraction of linear polarization are more likely to have a large Edot.

    ↳ astro-ph.HEhep-exhep-phRes.Astron.Astrophys.(2023)·55 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.