Mon·Jul 4, 2022Monday·July 4, 2022

1. 01*

   New benchmark scenarios of electroweak baryogenesis in aligned two Higgs double models

   Kazuki Enomoto🇯🇵 · Shinya Kanemura🇯🇵 · Yushi Mura🇯🇵

   We discuss electroweak baryogenesis in aligned two Higgs doublet models. It is known that in this model the severe constraint from the experimental results for the electron electric dipole moment can be avoided by destructive interference among CP-violating effects in the Higgs sector. In our previous work, we showed that the observed baryon number in the Universe can be explained without contradicting current available data in a specific scenario in the same model. We here first discuss details of the evaluation of baryon number based on the WKB method taking into account all order of the wall velocity. We then investigate parameter spaces which are allowed under the current available data from collider, flavor and electric dipole moment experiments simultaneously. We find several benchmark scenarios which can explain baryon asymmetry of the Universe. We also discuss how we can test these benchmark scenarios at future collider experiments, various flavor experiments and gravitational wave observations.

   hep-phJHEP(2022)·41 citations
2. 02*

   More Constraints on the Georgi-Machacek Model

   Zahra Bairi (U. Biskra, ENS-Kouba Algiers & U. Boumerdes)🇩🇿 · Amine Ahriche (U. Sharjah, ICTP Trieste & ENS-Kouba Algiers)🇮🇹

   In this work, we investigate the parameter space of the Georgi-Machacek (GM) model, where we consider many theoretical and experimental constraints such as the perturbativity, vacuum stability, unitarity, electroweak precision tests, the Higgs di-photon decay, the Higgs total decay width and the LHC measurements of the signal strengths of the SM-like Higgs boson $h$ in addition to the constraints from doubly charged Higgs bosons and Drell-Yan di-photon production and the indirect constraint from the $b\to s$ transition processes. We investigate also the possibility that the electroweak vacuum could be destabilized by unwanted wrong minima that may violate the CP and/or the electric charge symmetries. We found that about 40 \% of the parameter space that fulfills the above mentioned constraints; are excluded by these unwanted minima. In addition, we found that the negative searches for a heavy resonance could exclude a significant part of the viable parameter space; and future searches could exclude more regions in the parameter space.

   hep-phhep-exPRD(2023)·14 citations
3. 03*

   Optimal photon polarization toward the observation of the nonlinear Breit-Wheeler pair production

   Yunquan Gao🇨🇳 · Suo Tang🇨🇳

   We investigate the optimization of the photon polarization to increase the yield of the Breit-Wheeler pair production in arbitrarily polarized plane wave backgrounds. We show that the optimized photon polarization can improve the positron yield by more than $20\%$ compared to the unpolarized case, in the intensity regime of current laser-particle experiments. The seed photon's optimal polarization is resulting from the polarization coupling with the polarization of the laser pulse. The compact expressions of the coupling coefficients in both the perturbative and nonperturbative regime are given. Because of the evident difference in the coupling coefficients for the linear and circular polarization components, the seed photon's optimal polarization state in an elliptically polarized laser background, deviates considerably from the orthogonal state of the laser polarization.

   hep-phPRD(2022)·12 citations
4. 04*

   Direct and Indirect Methods of Vortex Identification in Continuum limit

   Sedigheh Deldar🇮🇷 · Zahra Asmaee🇮🇷

   Inspired by direct and indirect maximal center gauge methods which identify vortices in lattice calculations, and by using the connection formalism, we show that under some appropriate gauge transformations, vortices and chains appear in the continuum limit of QCD vacuum.

   hep-phRev.Mex.Fis.Suppl.(2022)·0 citations
5. 05*

   Anomaly-induced Chiral Mixing in Cold and Dense Matter

   Chihiro Sasaki🇵🇱

   We construct the spectral functions for light vector mesons at finite density and temperature in the presence of a novel mixing between parity partners, induced by baryon density via the Wess-Zumino-Witten action. As the main origin of in-medium broadening, a set of baryon resonances that strongly couple to the vector mesons and the modifications of kaons and anti-kaons due to the Kaplan-Nelson term are included. It is shown that the vector spectra, even with the broadening effects, exhibit sizable signatures of chiral symmetry restoration thanks to the chiral mixing depending on three-momenta carried by the vector mesons. Those spectral functions are used to calculate the integrated production rates of lepton pairs, and a proper binning in momenta and potential decrease in the vector-meson masses due to chiral symmetry restoration are discussed in quantifying the signatures.

   hep-phnucl-thPRD(2022)·9 citations
6. 06*

   The role of the $\omega (4S)$ and $\omega (3D)$ states in mediating the $e^{+}{e}^{-}\to \omega \eta$ and $\omega {\pi }^0{\pi }^0$ processes

   Qin-Song Zhou🇨🇳 · Jun-Zhang Wang🇨🇳 · Xiang Liu🇨🇳

   The $e^{+}{e}^{-}\to \omega \eta$ and $e^{+}{e}^{-}\to \omega {\pi }^0{\pi }^0$ processes are ideal platforms to search for higher $\omega$ states. Focusing on the observations of two enhancement structures around 2.2 GeV existing in $e^{+}{e}^{-}\to \omega \eta$ and $e^{+}{e}^{-}\to \omega {\pi }^0{\pi }^0$ at BESIII, we analyze how the $\omega (4S)$ and $\omega (3D)$ states play the role in the $e^{+}{e}^{-}\to \omega \eta$ and $e^{+}{e}^{-}\to \omega {\pi }^0{\pi }^0$ processes. The present study is supported by theoretical $\omega$ mesonic spectroscopy. For reproducing the data of the cross sections of $e^{+}{e}^{-}\to \omega \eta$ and $\omega {\pi }^0{\pi }^0$, the intermediate $\omega (4S)$ and $\omega (3D)$ should be introduced, which indicates that the enhancement structures around 2.2 GeV existing in $e^{+}{e}^{-}\to \omega \eta$ and $\omega {\pi }^0{\pi }^0$ contain the $\omega (4S)$ and $\omega (3D)$ signals. Nonetheless, in the process $e^{+}{e}^{-}\to \omega \eta$, the $\omega (4S)$ plays a dominant role, while the $\omega (4S)$ and $\omega (3D)$ have similar sizable contributions in the process of $e^{+}{e}^{-}\to \omega {\pi }^0{\pi }^0$, which leads to a difference in the line shape of enhancement structure in the cross sections under the interference effect. Thus, we find a solution to alleviate the puzzling difference of resonance parameter of two reported enhancement structures around 2.2 GeV existing in $e^{+}{e}^{-}\to \omega \eta$ and $e^{+}{e}^{-}\to \omega {\pi }^0{\pi }^0$ at BESIII. The present study provides valuable information to construct $\omega$ meson family, which can be accessible at future experiment like BESIII.

   hep-phhep-exPRD(2022)·12 citations
7. 07*

   Higgstory repeats itself

   Alessandro Strumia🇮🇹 · Nikolaos Tetradis🇬🇷

   We consider a scalar potential with two minima, one of which is arbitrarily deep, such as could be the case for the Higgs potential in the Standard Model. A recent calculation within the thin-wall approximation [arXiv:2205.10240] concludes that regions in which the scalar field takes values beyond the top of the potential barrier are forced by gravity to collapse, while they remain hidden behind a black hole horizon. We show that the thin-wall approximation is not applicable to this problem. We clarify the issue through numerical and analytical solutions to the field equations of the gravity-scalar system. We find that regions around the deeper minimum expand, and would thereby engulf the Universe in post-inflationary cosmology. We also show that black holes with Higgs hair are unstable. Even though the physics of the true vacuum is different, our final conclusion replicates the earlier `Higgstory' paper [arXiv:1505.04825].

   hep-phastro-ph.COgr-qchep-thJHEP(2022)·12 citations
8. 08*

   Electroweak renormalization based on gauge-invariant vacuum expectation values

   Stefan Dittmaier🇩🇪 · Heidi Rzehak🇩🇪

   We briefly review a recently proposed scheme for a gauge-invariant treatment of tadpole corrections in spontaneously broken gauge theories called Gauge-Invariant Vacuum expectation value Scheme (GIVS). The tadpole scheme matters in higher-order predictions of observables if not all free parameters are fixed by renormalization conditions based on S-matrix elements, such as in MSbar renormalization. In contrast to previously used tadpole schemes, the GIVS unifies the properties of gauge invariance and perturbative stability. The application of the GIVS to the Standard Model, for instance, leads to very moderate electroweak corrections in the conversion of on-shell-renormalized to MSbar-renormalized masses. Moreover, in models with extended Higgs sectors, the GIVS is less prone to perturbative instabilities in the MSbar renormalization of Higgs mixing angles than observed for the traditional gauge-independent tadpole treatment. We illustrate this by considering the next-to-leading-order (electroweak and QCD) corrections to the decay processes $h/H\to WW/ZZ\to 4$fermions of the CP-even neutral Higgs bosons h and H in a singlet Higgs extension of the Standard Model and in the Two-Higgs-Doublet Model.

   hep-phPoS(2022)·0 citations
9. 09*

   On Drell-Yan production of scalar leptoquarks coupling to heavy-quark flavours

   Ulrich Haisch🇩🇪 · Luc Schnell🇩🇪 · Stefan Schulte🇩🇪

   Given the hints of lepton-flavour non-universality in semi-leptonic $B$ decays, leptoquark (LQ) models with sizeable couplings to heavy-quark flavours are enjoying a renaissance. While such models are subject to stringent constraints from low-energy experiments also bounds from non-resonant dilepton searches at the Large Hadron Collider (LHC) turn out to be phenomenologically relevant. Based on the latest LHC dilepton analyses corresponding to an integrated luminosity of around $140{\mathrm{fb}}^{-1}$ of proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$, we present improved limits on the scalar LQ couplings that involve heavy-quark flavours and light or heavy dileptons. In particular, we show that effects beyond the leading order that are related to real QCD emissions are relevant in this context, since the inclusion of additional heavy-flavoured jets notably improves the exclusion limits that derive from the high-mass dilepton tails. The impact of electroweak corrections and interference effects between signal and background is also analysed. Within the POWHEG-BOX framework we provide a dedicated Monte Carlo code that allows for an on-the-fly signal event generation including all the LQ corrections considered in this article.

   hep-phhep-exJHEP(2022)·20 citations
10. 10*

    The Higgs boson Turns Ten

    Gavin P. Salam🇬🇧 · Lian-Tao Wang🇺🇸 · Giulia Zanderighi🇩🇪

    The discovery of the Higgs boson, ten years ago, was a milestone that opened the door to the study of a new sector of fundamental physical interactions. We review the role of the Higgs field in the Standard Model of particle physics and explain its impact on the world around us. We summarize the insights into Higgs physics revealed so far by ten years of work, discuss what remains to be determined, and outline potential connections of the Higgs sector with unsolved mysteries of particle physics.

    hep-phhep-exNature(2022)·36 citations
11. 11*

    Top-philic Dark Matter in a Hybrid KSVZ axion framework

    Anupam Ghosh🇮🇳 · Partha Konar🇮🇳 · Rishav Roshan🇰🇷

    We explore a two-component dark matter scenario in an extended Kim-Shifman-Vainshtein-Zakharov (KSVZ) axion framework. This hybrid setup incorporates an extra $SU(2{)}_L$ complex singlet scalar whose lightest component plays the role of one of the dark matter, while the QCD axion of the KSVZ model acts as a second dark matter candidate. In this work, we focus on accentuating the role of vector-like quark that naturally emerges in the KSVZ extension on the dark matter and collider phenomenology. Here, we demonstrate that the presence of this colored particle can significantly affect the allowed dark matter parameter space of the scalar dark matter by opening up additional co-annihilation as well as the direct detection channels. Moreover, the interaction between the color particle with the top quark and scalar dark matter provides a unique topology to generate a boosted-top pair with considerable missing transverse momentum at the LHC. Using jet substructure variables and multivariate analysis, here we show that one can already exclude a vast region of parameter space with 139 ${\text{fb}}^{-1}$ integrated luminosity at 14 TeV LHC.

    hep-phJHEP(2022)·23 citations
12. 12*

    Production of $P_c$ states in ${\Lambda }_b$ decays

    T.J. Burns🇬🇧 · E.S. Swanson🇺🇸

    We develop a model for the production of the Pc states observed at LHCb in Lambdab - Jpsi p K- decays. With fewer parameters than other approaches, we obtain excellent fits to the Jpsi-p invariant mass spectrum, capturing both the prominent peaks, and broader features over the full range of invariant mass. A distinguishing feature of our model is that whereas Pc(4312), Pc(4380), and Pc(4440) are resonances with Sigmac*-D* constituents, the nature of Pc(4457) is quite different, and can be understood either as a Sigmac-D* threshold cusp, a Lambdac(2595)-D enhancement due to the triangle singularity, or a Lambdac(2595)-D resonance. We propose experimental measurements that can discriminate among these possibilities. Unlike in other models, our production mechanism respects isospin symmetry and the empirical dominance of colour-enhanced processes in weak decays, and additionally gives a natural explanation for the overall shape of the data. Our model is consistent with experimental constraints from photoproduction and Lambdab - Lambdac-D(*)0 K- decays and it does not imply the existence of partner states whose apparent absence in experiments is unexplained in other models.

    hep-phPRD(2022)·30 citations
13. 13*

    Flavor hierarchies and B-anomalies from 5D

    Javier M. Lizana🇨🇭

    $B$-anomalies may suggest New Physics at the TeV scale breaking flavor universality. In particular, 4321 gauge models can successfully explain them in a consistent way. In this talk we explore how to UV complete the 4321 model in a 5D warped background to solve simultaneously the Higgs hierarchy problem too, finding interesting connections with the flavor puzzle. We present a model that addresses the $B$-anomalies, flavor hierarchies, and the Higgs hierarchy problem, where quarks and leptons are unified à la Pati-Salam in a non-universal way, and the Higgs appears as a pseudo-Nambu-Goldstone boson. These proceedings are based on arXiv:2203.01952.

    hep-ph0 citations
14. 14*

    An introduction to Thermal Field Theory and Some of its Application

    Munshi G. Mustafa🇮🇳

    In this article an introduction to the thermal field theory within imaginary time has been discussed in details. The imaginary time formalism has been introduced through both the operatorial and the functional integration method. The prescription to perform frequency sum for boson and fermion has been discussed. Green's function both in Minkowski time as well as in Euclidean time has been derived. The tadpole diagram in ${\varphi }^4$ theory and the self-energy in ${\varphi }^3$ theory have been computed. The basic features of general two point functions for both fermions and bosons in presence of a heat bath have been discussed. Then the free partition functions for scalar, fermion and gauge field, and interacting scalar field have been obtained. The quantum electrodynamics (QED) and gauge fixing have been discussed in details. The one-loop self-energy for electron and photon in QED have been obtained in hard thermal loop (HTL) approximation. The dispersion properties and collective excitations of both electron and photon in a thermal medium have been presented. The spectral representation of fermion and gauge boson propagators have been obtained. In HTL approximation, the generalisation of QED results of two point functions to quantum chromodynamics (QCD) have been outlined that mostly involve group theoretical factors. As an effective field theory approach the HTL resummation and the HTL perturbation theory have been introduced. The leading order, next-to-leading order and next-to-next-leading order free energy and pressure for deconfined QCD medium created in heavy-ion collisions have been computed within HTLpt. The general features of the deconfined QCD medium have also been outlined with non-perturbative effects like gluon condensate and Gribov-Zwanziger action. The dilepton production rates from quark-gluon plasma with these non-perturbative effects have been computed.

    hep-phhep-latnucl-thEur.Phys.J.ST(2023)·41 citations
15. 15*

    LIV in matter

    L. F. Urrutia🇲🇽

    We summarize recent work dealing with the characterization of effective actions giving the electromagnetic response of some topological materials, arising from their microscopic structure. The case of weakly tilted Weyl semimetals in the limit of zero temperature, but nonzero chemical potential, is presented as a subset of a specific choice of terms in the fermionic sector of the SME.

    hep-phcond-mat.mes-hall0 citations
16. 16*

    A Snowmass Whitepaper: Dark Matter Production at Intensity-Frontier Experiments

    G. Krnjaic🇺🇸 · N. Toro🇺🇸 · A. Berlin🇺🇸 · B. Batell🇺🇸 · N. Blinov🇨🇦 · L. Darme🇫🇷 · P. DeNiverville🇺🇸 · P. Harris🇺🇸 · C. Hearty🇨🇦 · M. Hostert🇨🇦 · K.J. Kelly🇨🇭 · D. McKeen🇨🇦 · S. Trojanowski🇵🇱 · Y.-D. Tsai🇺🇸

    Dark matter particles can be observably produced at intensity-frontier experiments, and opportunities in the next decade will explore important parameter space motivated by thermal DM models, the dark sector paradigm, and anomalies in data. This whitepaper describes the motivations, detection strategies, prospects and challenges for such searches, as well as synergies and complementarity both within RF6 and across HEP.

    hep-phastro-ph.COhep-ex65 citations
17. 17*

    Non-Standard Neutrino Spectra From Annihilating Neutralino Dark Matter

    Melissa van Beekveld🇬🇧 · Wim Beenakker🇳🇱 · Sascha Caron🇳🇱 · Jochem Kip🇳🇱 · Roberto Ruiz de Austri🇪🇸 · Zhongyi Zhang🇳🇱

    Neutrino telescope experiments are rapidly becoming more competitive in indirect detection searches for dark matter. Neutrino signals arising from dark matter annihilations are typically assumed to originate from the hadronisation and decay of Standard Model particles. Here we showcase a supersymmetric model, the BLSSMIS, that can simultaneously obey current experimental limits while still providing a potentially observable non-standard neutrino spectrum from dark matter annihilation.

    hep-phSciPost Phys.Core(2023)·2 citations
18. 18*

    Long live The NMSSM!

    Amit Adhikary🇵🇱 · Rahool Kumar Barman🇺🇸 · Biplob Bhattacherjee🇮🇳 · Amandip De🇮🇳 · Rohini M. Godbole🇮🇳 · Suchita Kulkarni🇦🇹

    We analyze the scenario within the Next to Minimal Supersymmetric Standard Model (NMSSM), where the lightest supersymmetric particle (LSP) is singlino-like neutralino. By systematically considering various possible admixtures in the electroweakino sector, we classify regions of parameter space where the next to lightest supersymmetric particle (NLSP) is a long-lived electroweakino while remaining consistent with constraints from flavor physics, dark matter direct detection, and collider data. We identify viable cascade decay modes featuring the long-lived NLSP for directly produced chargino-neutralino pairs, thus, leading to displaced vertex signatures at the high luminosity LHC (HL-LHC). We construct track based analysis in order to uncover such scenarios at the HL-LHC and analyze their discovery potential. We show that through such focused searches for the long-lived particles at the HL-LHC, one can probe regions of the electroweakino parameter space that are otherwise challenging.

    hep-phhep-exPRD(2023)·16 citations
19. 19*

    Equation of state in neutron stars and supernovae

    Kohsuke Sumiyoshi🇯🇵 · Toru Kojo🇯🇵 · Shun Furusawa🇯🇵

    Neutron stars and supernovae provide cosmic laboratories of highly compressed matter at supra nuclear saturation density which is beyond the reach of terrestrial experiments. The properties of dense matter is extracted by combining the knowledge of nuclear experiments and astrophysical observations via theoretical frameworks. A matter in neutron stars is neutron rich, and may further accommodate non-nucleonic degrees of freedom such as hyperons and quarks. The structure and composition of neutron stars are determined by equations of state of matter, which are the primary subject in this chapter. In case of supernovae, the time evolution includes several dynamical stages whose descriptions require equations of state at finite temperature and various lepton fractions. Equations of state also play essential roles in neutron star mergers which allow us to explore new conditions of matter not achievable in static neutron stars and supernovae. Several types of hadron-to-quark transitions, from first order transitions to crossover, are reviewed, and their characteristics are summarized.

    ↳ nucl-thastro-ph.HEhep-phpage 1-51, Handbook of Nuclear Physics, 2…·15 citations
20. 20*

    Revisiting diagonal tetrads: New Black Hole solutions in $f(T)$ gravity

    Adel Awad🇪🇬 · Alexey Golovnev🇪🇬 · María-José Guzmán🇪🇪 · Waleed El Hanafy🇪🇬

    We study various forms of diagonal tetrads that accommodate Black Hole solutions in $f(T)$ gravity with certain symmetries. As is well-known, vacuum spherically symmetric diagonal tetrads lead to rather boring cases of constant torsion scalars. We extend this statement to other possible horizon topologies, namely, spherical, hyperbolic and planar horizons. All such cases are forced to have constant torsion scalars to satisfy the anti-symmetric part of the field equations. We give a full classification of possible vacuum static solutions of this sort. Furthermore, we discuss addition of time-dependence in all the above cases. We also show that if all the components of a diagonal tetrad depend only on one coordinate, then the anti-symmetric part of the field equations is automatically satisfied. This result applies to the flat horizon case with Cartesian coordinates. For solutions with a planar symmetry (or a flat horizon), one can naturally use Cartesian coordinates on the horizon. In this case, we show that the presence of matter is required for existence of non-trivial solutions. This is a novel and very interesting feature of these constructions. We present two new exact solutions, the first is a magnetic Black Hole which is the magnetic dual of a known electrically charged Black Hole in literature. The second is a dyonic Black Hole with electric and magnetic charges. We present some features of these Black holes, namely, extremality conditions, mass, behavior of torsion and curvature scalars near the singularity.

    ↳ gr-qchep-phhep-thEPJC(2022)·23 citations
21. 21*

    Non-equilibrium charmonium regeneration in strongly coupled quark-gluon plasma

    Xiaojian Du🇩🇪 · Ralf Rapp🇺🇸

    The evaluation of quarkonium regeneration in ultrarelativistic heavy-ion collisions (URHICs) requires the knowledge of the heavy-quark phase space distributions in the expanding quark-gluon plasma (QGP) fireball. We employ a semi-classical charmonium transport approach where regeneration processes explicitly account for the time-dependent spectra of charm quarks via Langevin simulations of their diffusion. The inelastic charmonium rates and charm-quark transport coefficients are computed from the same charm-medium interaction. The latter is modeled by perturbative rates, augmented with a $K$-factor to represent nonperturbative interaction strength and interference effect. Using central 5.02~TeV Pb-Pb collisions as a test case we find that a good description of the measured $J/\psi$ yield and its transverse-momentum dependence can be achieved if a large $K\gtrsim 5$ is employed while smaller values lead to marked discrepancies. This is in line with open-charm phenomenology in URHICs, where nonperturbative interactions of similar strength are required. Our approach establishes a common transport framework for a microscopic description of open and hidden heavy-flavor (HF) observables that incorporates both nonperturbative and non-equilibrium effects, and thus enhances the mutual constraints from experiment on the extraction of transport properties of the QGP.

    ↳ nucl-thhep-phPLB(2022)·26 citations
22. 22*

    Velocity-dependent J-factors for Milky Way dwarf spheroidal analogues in cosmological simulations

    Keagan Blanchette🇨🇦 · Erin Piccirillo🇺🇸 · Nassim Bozorgnia🇨🇦 · Louis E. Strigari🇺🇸 · Azadeh Fattahi🇬🇧 · Carlos S. Frenk🇬🇧 · Julio F. Navarro🇨🇦 · Till Sawala🇫🇮

    We study the impact of the dark matter velocity distribution modelling on signals from velocity-dependent dark matter annihilation in Milky Way dwarf spheroidal galaxies. Using the high resolution APOSTLE simulations, we identify analogues corresponding to Milky Way dwarf spheroidal galaxies, and from these directly determine the dark matter pair-wise relative velocity distribution, and compare to best-fitting Maxwell-Boltzmann distribution models. For three velocity-dependent annihilation models, p-wave, d-wave, and the Sommerfeld model, we quantify the errors introduced when using the Maxwell-Boltzmann parameterization. We extract a simple power-law relation between the maximum circular velocity of the dwarf spheroidal analogue and the peak speed of the Maxwell-Boltzmann distribution. We show that this relation can be used to accurately calculate the dark matter relative velocity distribution, and find that it allows us to estimate the dark matter annihilation signal without the need to directly calculate the relative velocity distribution for each galaxy. The scatter in the J-factors calculated from the analogues dominates the uncertainty obtained when compared to the J-factor as determined from the observational data for each dwarf spheroidal, with the largest scatter from d-wave models and the smallest from Sommerfeld models.

    ↳ astro-ph.COastro-ph.GAhep-phJCAP(2023)·8 citations
23. 23*

    Search for Milli-Charged Particles from the Sun at IceCube

    Ye Xu🇨🇳

    It is assumed that heavy dark matter particles $\varphi$ with O(TeV) mass captured by the Sun may decay to relativistic light milli-charged particles (MCPs). These MCPs could be measured by the IceCube detector. The massless hidden photon model was taken for MCPs to interact with nuclei, so that the numbers and fluxes of expected MCPs and neutrinos may be evaluated at IceCube. Based on the assumption that no events are observed at IceCube in 6 years, the corresponding upper limits on MCP fluxes were calculated at 90\% C. L.. These results indicated that MCPs could be directly detected in the secondaries' energy range O(100GeV)-O(10TeV) at IceCube, when ${ϵ}^2\gtrsim 10^{-10}$. And a new region of 0.6 MeV < $m_{MCP}$ < 10 MeV and $6\times 10^{-6}$ < $ϵ$ $\lesssim$ $10^{-4}$ is ruled out in the $m_{MCP}$-$ϵ$ plane with 6 years of IceCube data.

    ↳ astro-ph.HEhep-phJHEP(2022)·4 citations
24. 24*

    Hidden-charm Hexaquarks from Lattice QCD

    Hang Liu🇨🇳 · Jinchen He🇨🇳 · Liuming Liu🇨🇳 · Peng Sun🇨🇳 · Wei Wang🇨🇳 · Yi-Bo Yang🇨🇳 · Qi-An Zhang🇨🇳

    We present a lattice QCD study of hidden-charm hexaquarks with quark content $usc\bar{d}\bar{s}\bar{c}$ based on four ensembles of gauge configurations generated by CLQCD Collaboration with pion mass in the range of 220-300MeV. Four operators with quantum numbers $0^{++},0^{-+},1^{++}$ and $1^{--}$ respectively are constructed to interpolate the hexaquarks. After validating the spectrum and the dispersion relation for ordinary hadrons, we calculate the masses of the hexaquarks and extrapolate the results to the physical pion mass and the continuum limit. We find that the masses of the four hexaquarks are all below the ${\Xi }_c{\bar{\Xi }}_c$ threshold, while the $0^{-+}$ hexaquark lies around the ${\eta }_c{K}^{+}{K}^{-}$ threshold. These results will be helpful for experimental searches in future and for a deep understanding of the nature of multiquark states.

    ↳ hep-lathep-exhep-phSCPMA(2024)·18 citations
25. 25*

    Quantum nucleation of topological solitons

    Minoru Eto🇯🇵 · Muneto Nitta🇯🇵

    The chiral soliton lattice is an array of topological solitons realized as ground states of QCD at finite density under strong magnetic fields or rapid rotation, and chiral magnets with an easy-plane anisotropy. In such cases, topological solitons have negative energy due to topological terms originating from the chiral magnetic or vortical effect and the Dzyaloshinskii-Moriya interaction, respectively. We study quantum nucleation of topological solitons in the vacuum through quantum tunneling in $2+1$ and $3+1$ dimensions, by using a complex ${\varphi }^4$ (or the axion) model with a topological term proportional to an external field, which is a simplification of low-energy theories of the above systems. In $2+1$ dimensions, a pair of a vortex and an anti-vortex is connected by a linear soliton, while in $3+1$ dimensions, a vortex is string-like, a soliton is wall-like, and a disk of a soliton wall is bounded by a string loop. Since the tension of solitons can be effectively negative due to the topological term, such a composite configuration of a finite size is created by quantum tunneling and subsequently grows rapidly. We estimate the nucleation probability analytically in the thin-defect approximation and fully calculate it numerically using the relaxation (gradient flow) method. The nucleation probability is maximized when the direction of the soliton is perpendicular to the external field. We find a good agreement between the thin-defect approximation and direct numerical simulation in $2+1$ dimensions if we read the vortex tension from the numerics, while we find a difference between them at short distances interpreted as a remnant energy in $3+1$ dimensions.

    ↳ hep-thcond-mat.mes-hallhep-phJHEP(2022)·28 citations
26. 26*

    Formation of Chiral Soliton Lattice

    Tetsutaro Higaki🇯🇵 · Kohei Kamada🇯🇵 · Kentaro Nishimura🇯🇵

    The Chiral Soliton Lattice (CSL) is a lattice structure composed of domain walls aligned in parallel at equal intervals, which is energetically stable in the presence of a background magnetic field and a finite (baryon) chemical potential due to the topological term originated from the chiral anomaly. We study its formation from the vacuum state, with describing the CSL as a layer of domain-wall disks surrounded by the vortex or string loop, based on the Nambu-Goto-type effective theory. We show that the domain wall nucleates via quantum tunneling when the magnetic field is strong enough. We evaluate its nucleation rate and determine the critical magnetic field strength with which the nucleation rate is no longer exponentially suppressed. We apply this analysis to the neutral pion in the two-flavor QCD as well as the axion-like particles (ALPs) with a finite (baryon) chemical potential under an external magnetic field. In the former case, even though the CSL state is more energetically stable than the vacuum state and the nucleation rate becomes larger for sufficiently strong magnetic field, it cannot be large enough so that the nucleation of the domain walls is not exponentially suppressed and promoted, without suffering from the tachyonic instability of the charged pion fluctuations. In the latter case, we confirm that the effective interaction of the ALPs generically includes the topological term required for the CSL state to be energetically favored. We show that the ALP CSL formation is promoted if the magnetic field strength and the chemical potential of the system is slightly larger than the scale of the axion decay constant.

    ↳ hep-thastro-ph.COcond-mat.mes-hallhep-ph+1PRD(2022)·29 citations
27. 27*

    Initial conditions for the scalaron dark matter

    Yuri Shtanov🇺🇦

    The scalaron of the metric $f(R)$ gravity can constitute dark matter if its mass is in the range $4\text{meV}\lesssim m\lesssim 1\text{MeV}$. We give an overview of such $f(R)$ gravity theory minimally coupled to the Standard Model. Similarly to other dark-matter models based on scalar fields, this model has the issue of initial conditions. Firstly, the initial conditions for the scalaron are to be tuned in order to produce the observed amount of dark matter. Secondly, the primordial spatial inhomogeneities in the field are to be sufficiently small because they generate entropy (or isocurvature) perturbations, which are constrained by observations. We consider these issues in the present paper. The initial conditions for the scalaron presumably emerge at the inflationary stage. We point out that the homogeneous part of the scalaron initial value is largely unpredictable because of quantum diffusion during inflation. Thus, to account for the observed amount of dark matter, one has to resort to anthropic considerations. Observational constraints on the primordial spatial inhomogeneity of the scalaron are translated into upper bounds on the energy scale of inflation, which happen to be low but not too restrictive.

    ↳ astro-ph.COgr-qchep-phJCAP(2022)·18 citations
28. 28*

    Gravitational Particle Production and the Validity of Effective Descriptions in Loop Quantum Cosmology

    Gustavo S. Vicente🇧🇷 · Rudnei O. Ramos🇧🇷 · Leila L. Graef🇧🇷

    The effective approach in Loop Quantum Cosmology (LQC) has provided means to obtain predictions for observable quantities in LQC models. While an effective dynamics in LQC has been extensively considered in different scenarios, a robust demonstration of the validity of effective descriptions for the perturbative level still requires further attention. The consistency of the description adopted in most approaches requires the assumption of a test field approximation, which is limited to the cases in which the backreaction of the particles gravitationally produced can be safely neglected. Within the framework of LQC, some of the main approaches to quantize the linear perturbations are the dressed metric, the hybrid approaches and the closed/deformed algebra approach. Here, we analyze the consistency of the test field assumption in these frameworks by computing the energy density stored in the particles gravitationally produced compared to the background energy density. This analysis ultimately provides us with a consistency test of the effective descriptions of LQC.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRD(2022)·8 citations
29. 29*

    Gravitational leptogenesis from metric perturbations

    Antonio L. Maroto🇪🇸 · Alfredo D. Miravet🇪🇸

    In this work we make the observation that the gravitational leptogenesis mechanism can be implemented without invoking new axial couplings in the inflaton sector. We show that in the perturbed Robertson-Walker background emerging after inflation, the spacetime metric itself breaks parity symmetry and generates a non-vansihing Pontryagin density which can produce a matter-antimatter asymmetry. We analyze the produced asymmetry in different inflationary and reheating scenarios. We show that the generated asymmetry can be locally comparable to observations in certain cases, although the size of the matter-antimatter regions is typically much smaller than the present Hubble radius.

    ↳ astro-ph.COgr-qchep-phPRD(2023)·2 citations
30. 30*

    Catch-Me-If-You-Can: The Overshoot Problem and the Weak/Inflation Hierarchy

    Joseph P. Conlon🇬🇧 · Filippo Revello🇬🇧

    We study the overshoot problem in the context of post-inflationary string cosmology (in particular LVS). LVS cosmology features a long kination epoch as the volume modulus rolls down the exponential slope towards the final minimum, with an energy density that scales as $m_s^4$. This roll admits attractor tracker solutions, and if these are located the overshoot problem is solved. We show that, provided a sufficiently large hierarchy exists between the inflationary scale and the weak scale, this will always occur in LVS as initial seed radiation grows into the tracker solution. The consistency requirement of ending in a stable vacuum containing the weak hierarchy therefore gives a preference for high inflationary scales -- an anthropic argument, if one likes, for a large inflation/weak hierarchy. We discuss various origins, both universal and model-dependent, of the initial seed radiation (or matter). One particularly interesting case is that of a fundamental string network arising from brane inflation -- this may lead to an early epoch in which the universe energy density principally consists of gravitational waves, while an LVS fundamental string network survives into the present universe.

    ↳ hep-thastro-ph.COhep-phJHEP(2022)·45 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.