Wed·Mar 23, 2022Wednesday·March 23, 2022

1. 01*

   Mixed QCD-electroweak corrections to dilepton production at the LHC in the high invariant mass region

   Federico Buccioni🇬🇧 · Fabrizio Caola🇬🇧 · Herschel A. Chawdhry🇬🇧 · Federica Devoto🇬🇧 · Matthias Heller🇩🇪 · Andreas von Manteuffel🇺🇸 · Kirill Melnikov🇩🇪 · Raoul Röntsch🇮🇹 · Chiara Signorile-Signorile🇩🇪

   We compute mixed QCD-electroweak corrections to the neutral-current Drell-Yan production of a pair of massless leptons in the high invariant mass region. Our computation is fully differential with respect to the final state particles. At relatively low values of the dilepton invariant mass, $m_{\ell \ell }\sim 200$ GeV, we find unexpectedly large mixed QCD-electroweak corrections at the level of -1%. At higher invariant masses, $m_{\ell \ell }\sim 1$ TeV, we observe that these corrections can be well approximated by the product of QCD and electroweak corrections. Hence, thanks to the well-known Sudakov enhancement of the latter, they increase at large invariant mass and reach e.g. -3% at $m_{\ell \ell }=3$ TeV. Finally, we note that the inclusion of mixed corrections reduces the theoretical uncertainty related to the choice of electroweak input parameters to below the percent level.

   hep-phhep-exJHEP(2022)·58 citations
2. 02*

   The medium-modified $g\to c\bar{c}$ splitting function in the BDMPS-Z formalism

   Maximilian Attems🇨🇭 · Jasmine Brewer🇨🇭 · Gian Michele Innocenti🇨🇭 · Aleksas Mazeliauskas🇨🇭 · Sohyun Park🇨🇭 · Wilke van der Schee🇨🇭 · Urs Achim Wiedemann🇨🇭

   The formalism of Baier-Dokshitzer-Mueller-Peigné-Schiff and Zakharov determines the modifications of parton splittings in the QCD plasma that arise from medium-induced gluon radiation. Here, we study medium-modifications of the gluon splitting into a quark--anti-quark pair in this BDMPS-Z formalism. We derive a compact path-integral formulation that resums effects from an arbitrary number of interactions with the medium to leading order in the $1/N_c^2$ expansion. Analyses in the $N=1$ opacity and the saddle point approximations reveal two phenomena: a medium-induced momentum broadening of the relative quark--anti-quark pair momentum that increases the invariant mass of quark--anti-quark pairs, and a medium-enhanced production of such pairs. We note that both effects are numerically sizeable if the average momentum transfer from the medium is comparable to the quark mass. In ultra-relativistic heavy-ion collisions, this condition is satisfied for charm quarks. We therefore focus our numerical analysis on the medium modification of $g\to c\bar{c}$, although our derivation applies equally well to $g\to b\bar{b}$ and to gluons splitting into light-flavoured quark--anti-quark pairs.

   hep-phhep-thnucl-exnucl-thJHEP(2023)·36 citations
3. 03*

   Semileptonic decays of $\rho$, $\omega$, $\varphi$, $\eta$ and ${\eta }^{\prime }$ mesons in ground and first radially excited states in the $U(3)\times U(3)$ NJL model

   M.K. Volkov🇷🇺 · K. Nurlan🇷🇺

   In the extended $U(3)\times U(3)$ NJL model, semileptonic decays of $\rho$, $\omega$, $\varphi$, $\eta$ and ${\eta }^{\prime }$ mesons in both the ground and first radially excited states are described. Quark loops of the anomalous type are considered, which are based on the vertex $\eta \to VV$. The obtained results are in satisfactory agreement with the existing experimental data. In addition, a number of predictions for experimentally unmeasured decays of radially excited mesons are presented.

   hep-phInt.J.Theor.Phys.(2022)·1 citation
4. 04*

   Cluster Hadronisation in Sherpa

   Gurpreet Singh Chahal🇬🇧 · Frank Krauss🇬🇧

   We present the Sherpa cluster hadronization model and a simple model for non-perturbative colour reconnections. Using two different parton shower implementations we tuned the model to data and we show typical resulting distributions that are sensitive to hadronization effects in $e^{+}{e}^{-}$--annihilations into hadrons.

   hep-phhep-exSciPost Phys.(2022)·53 citations
5. 05*

   Snowmass2021 Whitepaper: Muonium to antimuonium conversion

   Ai-Yu Bai🇨🇳 · Yu Chen🇨🇳 · Yukai Chen🇨🇳 · Rui-Rui Fan🇨🇳 · Zhilong Hou🇨🇳 · Han-Tao Jing🇨🇳 · Hai-Bo Li🇨🇳 · Yang Li · Han Miao🇨🇳 · Huaxing Peng🇨🇳 · Alexey A. Petrov (Coordindator)🇺🇸 · Ying-Peng Song🇨🇳 and 12 other authors

   The spontaneous muonium to antimuonium conversion is one of the interesting charged lepton flavor violation processes. It serves as a clear indication of new physics and plays an important role in constraining the parameter space beyond Standard Model. MACE is a proposed experiment to probe such a phenomenon and expected to enhance the sensitivity to the conversion probability by more than two orders of magnitude from the current best upper constraint obtained by the PSI experiment two decades ago. Recent developments in the theoretical and experimental aspects to search for such a rare process are summarized.

   hep-phhep-ex28 citations
6. 06*

   CP violation in $B_s$ decays mediated by two nearly-degenerate Majorana neutrinos

   Guangshuai Zhang🇨🇳 · Bo-Qiang Ma🇨🇳

   We study the \textit{CP} violation in the lepton-number-violating process $B_s^0\to D_s^{-}{\mu }^{+}{\mu }^{+}{\pi }^{-}$ and its \textit{CP}-conjugate process $\overline{B_s^0}\to D_s^{+}{\mu }^{-}{\mu }^{-}{\pi }^{+}$ that are induced by two GeV-scale Majorana neutrinos with nearly-degenerate masses. Our result shows that the size of the \textit{CP} violation could become considerable if the mass difference between the two Majorana neutrinos is around the decay width of the neutrinos. We perform experimental analysis on the \textit{CP}-violating processes at LHCb within its upgrade II. The analysis shows that under current constraint on the heavy-light neutrino mixing parameter, it is possible that such \textit{CP} violation is observed with the LHCb experimental ability. We also give the upper bound on the heavy-light mixing parameter $|U_{\mu N}{|}^2$ under the assumption that no positive signal of the process is observed. The result shows that such modes can give complementary constraint compared with previous experiments such as NuTeV, BEBC, etc. in the mass region 1~GeV $<m_N<$ 3~GeV.

   hep-phPRD(2022)·0 citations
7. 07*

   Co-positivity of tensors and bounded from below conditions of CP conserving two-Higgs-doublet potential

   Yisheng Song🇨🇳

   In this paper, the analytic sufficient and necessary conditions are obtained for the CP conserving two-Higgs-doublet potential to be bounded from below by using the co-positivity of tensors. This is achieved by treating the potential as a quartic homogeneous polynomial about the moduli of the two Higgs doublet fields, where the 'angles' is described as the misalignment of the two doublets, then solving three minimum problems with respect to the misalignment. Finally, the analytic conditions are established with the help of the corresponding theory and methods of higher order tensors.

   hep-phmath-phmath.MPmath.OCInt.J.Mod.Phys.A(2023)·5 citations
8. 08*

   A comprehensive guide to the physics and usage of PYTHIA 8.3

   Christian Bierlich🇸🇪 · Smita Chakraborty🇸🇪 · Nishita Desai🇮🇳 · Leif Gellersen🇸🇪 · Ilkka Helenius🇫🇮 · Philip Ilten🇺🇸 · Leif Lönnblad🇸🇪 · Stephen Mrenna🇺🇸 · Stefan Prestel🇸🇪 · Christian T. Preuss🇦🇺 · Torbjörn Sjöstrand🇸🇪 · Peter Skands🇦🇺 · Marius Utheim🇸🇪 · Rob Verheyen🇬🇧

   This manual describes the PYTHIA 8.3 event generator, the most recent version of an evolving physics tool used to answer fundamental questions in particle physics. The program is most often used to generate high-energy-physics collision "events", i.e. sets of particles produced in association with the collision of two incoming high-energy particles, but has several uses beyond that. The guiding philosophy is to produce and reproduce properties of experimentally obtained collisions as accurately as possible. The program includes a wide ranges of reactions within and beyond the Standard Model, and extending to heavy ion physics. Emphasis is put on phenomena where strong interactions play a major role. The manual contains both pedagogical and practical components. All included physics models are described in enough detail to allow the user to obtain a cursory overview of used assumptions and approximations, enabling an informed evaluation of the program output. A number of the most central algorithms are described in enough detail that the main results of the program can be reproduced independently, allowing further development of existing models or the addition of new ones. Finally, a chapter dedicated fully to the user is included towards the end, providing pedagogical examples of standard use cases, and a detailed description of a number of external interfaces. The program code, the online manual, and the latest version of this print manual can be found on the PYTHIA web page: https://www.pythia.org/

   hep-phhep-exSciPost Phys.Codeb.(2022)·1752 citations
9. 09*

   Exclusive $J/\psi$ photoproduction in ultraperipheral Pb+Pb collisions at the LHC to next-to-leading order perturbative QCD

   Kari J. Eskola🇫🇮 · Christopher A. Flett🇫🇮 · Vadim Guzey🇫🇮 · Topi Löytäinen🇫🇮 · Hannu Paukkunen🇫🇮

   We present the first next-to-leading-order (NLO) perturbative QCD (pQCD) study of rapidity-differential cross sections of coherent exclusive photoproduction of $J/\psi$ mesons in heavy-ion ultraperipheral collisions (UPCs) at the LHC, $d\sigma /dy(\text{Pb}+\text{Pb}\to \text{Pb}+J/\psi +\text{Pb})$. For this, we account for the photon-nucleon NLO cross sections at the forward limit, the $t$ dependence using a standard nuclear form factor, and the photon fluxes of the colliding nuclei. Approximating the generalized parton distributions with their forward-limit parton distribution functions (PDFs), we quantify the NLO contributions in the cross sections, show that the real part of the amplitude and quark-PDF contributions must not be neglected, quantify the uncertainties arising from the scale-choice and PDFs, and compare our results with ALICE, CMS and LHCb $J/\psi$ photoproduction data in Pb+Pb UPCs, exclusive $J/\psi$ photoproduction data from HERA, and LHCb data in p+p. The scale dependence in $d\sigma /dy(\text{Pb}+\text{Pb}\to \text{Pb}+J/\psi +\text{Pb})$ is significant, but we can find a scale-choice that reproduces the Pb+Pb UPC data both at 2.76 and 5.02 TeV collision energies. This process has traditionally been suggested to be a direct probe of nuclear gluon distributions. We show that the situation changes rather dramatically from LO to NLO: the NLO cross sections reflect the nuclear effects of both gluons and quarks in a complicated manner where the relative signs of the LO and NLO terms in the amplitude play a significant role.

   hep-phPRC(2022)·80 citations
10. 10*

    Neutrino interactions with ultralight axion-like dark matter

    Matías M. Reynoso🇦🇷 · Oscar A. Sampayo🇦🇷 · Agustín M. Carulli🇦🇷

    In this work, we study the propagation of high energy neutrinos produced in extragalactic sources including the effect of a possible interaction with ultralight axion-like particles (UALP) with a mass $m_a\sim 10^{-22}\mathrm{eV}$ as the constituents of dark matter (DM) under the assumption that their coupling to neutrinos is dominant. We compute the cross section and describe the propagation of a diffuse neutrino flux using transport equations for each mass eigenstate. This allows us to obtain the neutrino fluxes of the different flavors to be observed at the Earth with neutrino telescopes under different assumptions for the flavor composition emitted at the sources and for a normal ordering (NO) or an inverted ordering (IO) of the neutrino masses. If the coupling of neutrinos with UALPs is the same for all flavors ($g_{\nu a}$), we find that interactions change the flavor composition of neutrinos arriving on Earth for $g_{\nu a}\gtrsim 0.5{\mathrm{GeV}}^{-1}$, causing the electron(muon) flavor to dominate in the NO(IO) case for neutrino energies above $\sim 10^5\mathrm{GeV}$. Although current data on the flavor ratios suggest that interactions with UALP DM do not take place within the range of coupling studied (particularly in the NO case) more data is needed to improve the precision of the experimentally measured flavor composition.

    hep-phEPJC(2022)·23 citations
11. 11*

    Sensitivity to Dark Sector Scales from Gravitational Wave Signatures

    James B. Dent🇺🇸 · Bhaskar Dutta🇺🇸 · Sumit Ghosh🇺🇸 · Jason Kumar🇺🇸 · Jack Runburg🇺🇸

    We consider gravitational wave signals produced by a first-order phase transition in a theory with a generic renormalizable thermal effective potential of power law form. We find the frequency and amplitude of the gravitational wave signal can be related in a straightforward manner to the parameters of the thermal effective potential. This leads to a general conclusion; if the mass of the dark Higgs is less than 1% of the dark Higgs vacuum expectation value, then the gravitational wave signal will be unobservable at all upcoming and planned gravitational wave observatories.

    hep-phastro-ph.COJHEP(2022)·29 citations
12. 12*

    A substandard candle: the low-$\nu$ method at few-GeV neutrino energies

    Callum Wilkinson🇺🇸 · Stephen Dolan🇨🇭 · Luke Pickering🇬🇧 · Clarence Wret🇺🇸

    As accelerator-neutrino oscillation experiments improve oscillation parameter constraints, control over systematic uncertainties on the incoming neutrino flux and interaction models is increasingly important. The intense beams offered by modern experiments permit a variety of options to constrain the flux using in situ "standard candle" measurements. These standard candles must use very well understood processes to avoid introducing bias. One option discussed in this context is the "low-$\nu$" method, designed to isolate neutrino interactions where there is low energy-transfer to the nucleus, such that the cross section is expected to be approximately constant as a function of neutrino energy. The shape of the low-energy transfer event sample can then be used to extract the flux shape. Applications of the method at high neutrino energies (many tens of GeV) are well understood. However, the applicability of the method at the few-GeV energies of current and future accelerator neutrino experiments remains unclear due to the presence of nuclear and form-factor effects. In this analysis we examine the prospects for improving constraints on accelerator neutrino fluxes with the low-$\nu$ method in an experiment-independent way, using (anti)neutrino interactions on argon and hydrocarbon targets from the GENIE, NEUT, NuWro and GiBUU event generators. The results show that flux constraints from the low-$\nu$ method would be severely dependent on the specific interaction model assumptions used in an analysis for neutrino energies less than 5 GeV. The spread of model predictions show that a low-$\nu$ analysis is unlikely to offer much improvement on typical neutrino flux uncertainties, even with a perfect detector. Notably -- running counter to the assumption inherent to the low-$\nu$ method -- the model-dependence increases with decreasing energy transfer for experiments in the few-GeV region.

    hep-phhep-exEPJC(2022)·15 citations
13. 13*

    Can Transverse Mass Scaling Shed Light on the Event-Activity Dependence of ${\rm Y}$ Mesons Production at LHC?

    Iakov Aizenberg (1)🇮🇱 · Zvi Citron (2)🇮🇱 · Alexander Milov (1) ((1) Department of Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel (2) Department of Physics, Ben Gurion University of the Negev, Beer Sheva, Israel)🇮🇱

    Measurements by the CMS experiment [CMS Collaboration, JHEP04 (2014) 103; CMS Collaboration, JHEP11 (2020) 001] reveal a deficit of charged particle tracks in events with higher ${\rm Y}$(nS) states. This observation is suggested to be a manifestation of the excited bottomonia suppression in $pp$ interactions. Transverse mass ($m_{\mathrm{T}}$) scaling can be implied to check this assumption in an independent way. The scaling has been observed for a wide range of particle species in proton-proton collisions at various energies from the SPS to RHIC and the LHC. The observed scaling is known to be different for baryons and mesons, and this work presents a comprehensive study of the $m_{\mathrm{T}}$-scaling of mesons at LHC energies with a focus on heavier mesons. The study demonstrates patterns in the scaling properties of mesons, which are related to the particle quark content. In particular, light species and ground-state quarkonia obey the same scaling, whereas open-flavor particles deviate from it because their spectra are significantly harder. The magnitude of deviation depends on the flavor of the heaviest quark in the meson. By extending the $m_{\mathrm{T}}$-scaling assumption to the excited bottomonia states, it is observed that the measured cross sections of ${\rm Y}$(2S) and ${\rm Y}$(3S) are reduced by factors of 1.6 and 2.4 compared to the expectation from the scaling. This observation is consistent with recently observed differences between the event-activity dependence of different ${\rm Y}$(nS) meson states.

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

    Utilizing high-$p_{\perp }$ theory and data to constrain the initial stages of quark-gluon plasma

    Bojana Ilic🇷🇸 · Dusan Zigic🇷🇸 · Marko Djordjevic🇷🇸 · Magdalena Djordjevic🇷🇸

    The scarce knowledge of the initial stages of quark-gluon plasma before the thermalization is mostly inferred through the low-$p_{\perp }$ sector. We propose a complementary approach in this report - the use of high-$p_{\perp }$ probes' energy loss. We study the effects of four commonly assumed initial stages, whose temperature profiles differ only before the thermalization, on high-$p_{\perp }$ $R_{AA}$ and $v_2$ predictions. The predictions are based on our Dynamical Radiative and Elastic ENergy-loss Approach (DREENA) framework. We report insensitivity of $v_2$ to the initial stages, making it unable to distinguish between different cases. $R_{AA}$ displays sensitivity to the presumed initial stages, but current experimental precision does not allow resolution between these cases. We further revise the commonly accepted procedure of fitting the energy loss parameters, for each individual initial stage, to the measured $R_{AA}$. We show that the sensitivity of $v_2$ to various initial stages obtained through such procedure is mostly a consequence of fitting procedure, which may obscure the physical interpretations. Overall, the simultaneous study of high-$p_{\perp }$ observables, with unchanged energy loss parametrization and restrained temperature profiles, is crucial for future constraints on initial stages.

    hep-phnucl-thIJMPE(2021)·3 citations
15. 15*

    Portraying Double Higgs at the Large Hadron Collider II

    Li Huang🇺🇸 · Su-beom Kang🇰🇷 · Jeong Han Kim🇰🇷 · Kyoungchul Kong🇺🇸 · Jun Seung Pi🇰🇷

    The Higgs potential is vital to understand the electroweak symmetry breaking mechanism, and probing the Higgs self-interaction is arguably one of the most important physics targets at current and upcoming collider experiments. In particular, the triple Higgs coupling may be accessible at the HL-LHC by combining results in multiple channels, which motivates to study all possible decay modes for the double Higgs production. In this paper, we revisit the double Higgs production at the HL-LHC in the final state with two $b$-tagged jets, two leptons and missing transverse momentum. We focus on the performance of various neural network architectures with different input features: low-level (four momenta), high-level (kinematic variables) and image-based. We find it possible to bring a modest increase in the signal sensitivity over existing results via careful optimization of machine learning algorithms making a full use of novel kinematic variables.

    hep-phhep-exJHEP(2022)·17 citations
16. 16*

    The Exclusive Vision of Rare $K$ and $B$ Decays and of the Quark Mixing in the Standard Model

    Andrzej J. Buras🇩🇪 · Elena Venturini🇩🇪

    The most common predictions for rare $K$ and $B$ decay branching ratios in the Standard Model are based on the CKM elements $|V_{cb}|$ and $|V_{ub}|$ resulting from global fits, that are in the ballpark of their inclusive and exclusive determinations, respectively. In the present paper we follow another route. We assume that the future true values of $|V_{cb}|$ and $|V_{ub}|$ will be both from exclusive determinations and set them equal to the most recent ones from FLAG. An unusual pattern of SM predictions results from this study with some existing tensions being dwarfed and new tensions being born. In particular using the HPQCD $B_{s,d}^0-{\bar{B}}_{s,d}^0$ hadronic matrix elements a $3.1\sigma$ tension in $\Delta M_s$ independently of $\gamma$ is found. For $60^{\circ }\le \gamma \le 75^{\circ }$ the tension in $\Delta M_d$ between $4.0\sigma$ and $1.1\sigma$ is found and in the case of ${ϵ}_K$ between $5.2\sigma$ and $2.1\sigma$. Moreover, the room for new physics in $K^{+}\to {\pi }^{+}\nu \bar{\nu }$, $K_L\to {\pi }^0\nu \bar{\nu }$ and $B\to K(K^{\ast })\nu \bar{\nu }$ decays is significantly increased. We compare the results in this EXCLUSIVE scenario with the HYBRID one in which $|V_{cb}|$ in the former scenario is replaced by the most recent inclusive $|V_{cb}|$ and present the dependence of all observables considered by us in both scenarios as functions of $\gamma$. We also compare the determination of $|V_{cb}|$ from $\Delta M_s$, $\Delta M_d$, ${ϵ}_K$ and $S_{\psi K_S}$ using $B_{s,d}^0-{\bar{B}}_{s,d}^0$ hadronic matrix elements from LQCD with $2+1+1$ flavours, $2+1$ flavours and their average. Only for the $2+1+1$ case values for $\beta$ and $\gamma$ exist for which the same value of $|V_{cb}|$ is found: $|V_{cb}|=42.6(4)\times 10^{-3}$. This in turn implies a $2.7\sigma$ anomaly in $B_s\to {\mu }^{+}{\mu }^{-}$.

    hep-phhep-exhep-latEPJC(2022)·92 citations
17. 17*

    Introducing DMRadio-GUT, a search for GUT-scale QCD axions

    L. Brouwer🇺🇸 · S. Chaudhuri🇺🇸 · H.-M. Cho🇺🇸 · J. Corbin🇺🇸 · C. S. Dawson🇺🇸 · A. Droster🇺🇸 · J. W. Foster🇺🇸 · J. T. Fry🇺🇸 · P. W. Graham🇺🇸 · R. Henning🇺🇸 · K. D. Irwin🇺🇸 · F. Kadribasic🇺🇸 and 20 other authors

    The QCD axion is a leading dark matter candidate that emerges as part of the solution to the strong CP problem in the Standard Model. The coupling of the axion to photons is the most common experimental probe, but much parameter space remains unexplored. The coupling of the QCD axion to the Standard Model scales linearly with the axion mass; therefore, the highly-motivated region 0.4-120 neV, corresponding to a GUT-scale axion, is particularly difficult to reach. This paper presents the design requirements for a definitive search for GUT-scale axions and reviews the technological advances needed to enable this program.

    ↳ hep-exhep-phPRD(2022)·95 citations
18. 18*

    Neutrino Scattering Measurements on Hydrogen and Deuterium: A Snowmass White Paper

    Luis Alvarez-Ruso🇪🇸 · Joshua L. Barrow🇺🇸 · Leo Bellantoni🇺🇸 · Minerba Betancourt🇺🇸 · Alan Bross🇺🇸 · Linda Cremonesi🇬🇧 · Kirsty Duffy🇬🇧 · Steven Dytman🇺🇸 · Laura Fields🇺🇸 · Tsutomu Fukuda🇯🇵 · Diego González-Díaz🇪🇸 · Mikhail Gorchtein🇩🇪 and 21 other authors

    Neutrino interaction uncertainties are a limiting factor in current and next-generation experiments probing the fundamental physics of neutrinos, a unique window on physics beyond the Standard Model. Neutrino-nucleon scattering amplitudes are an important part of the neutrino interaction program. However, since all modern neutrino detectors are composed primarily of heavy nuclei, knowledge of elementary neutrino-nucleon amplitudes relies heavily on experiments performed in the 1970s and 1980s, whose statistical and systematic precision are insufficient for current needs. In this white paper, we outline the motivation for attempting measurements on hydrogen and deuterium that would improve this knowledge, and we discuss options for making these measurements either with the DUNE near detector or with a dedicated facility.

    ↳ hep-exhep-ph23 citations
19. 19*

    Color confinement, chiral symmetry breaking, and catalytic effect induced by monopole and instanton creations

    Masayasu Hasegawa🇷🇺

    Our research reveals the relations among monopoles, color confinement, instantons, and chiral symmetry breaking which experiments can detect, by numerical calculations of lattice gauge theory. We first add a monopole and an anti-monopole varying their magnetic charges to the gauge field configurations in the quenched approximation of quantum chromodynamics (QCD), by applying the monopole creation operator and investigate the effects of the added monopoles and anti-monopoles on color confinement. Second, we reveal the quantitative relations among instantons, anti-instantons, and observables using the eigenvalues and eigenvectors of the overlap Dirac operator, which are calculated using the normal configurations and the configurations with the additional monopoles and anti-monopoles. Finally, we ascertain the outcomes by comparing them with the predictions. We have already discovered the catalytic effect: the decay width of the charged pion becomes wider and its lifetime becomes shorter than the experimental outcomes by increasing the number density of instantons and anti-instantons. However, the outcomes in the previous study were obtained using one lattice volume and lattice spacing. In this research, we improve the previous study using a variety of configurations of different lattice volumes and values of the lattice spacing from low to finite temperatures. The main purposes of this study are to inspect the influences of the finite lattice volume and discretization on the observables and quantitative relations that we have obtained in our previous research and to acquire the interpolated results at the continuum limit.

    ↳ hep-lathep-exhep-phEPJC(2022)·4 citations
20. 20*

    Unitarity Problems for an Effective Field Theory Description of Early Universe Cosmology

    Robert Brandenberger🇨🇦 · Vahid Kamali (McGill University)🇨🇦

    In the context of Effective Field Theory, the Hilbert space of states increases in an expanding universe. Hence, the time evolution cannot be unitary. The formation of structure is usually studied using effective field theory techniques. We study the constraints on effective field theory analyses of early universe models which come from demanding that the factor of the space of states corresponding to length scales where the primordial fluctuations are manifest does not suffer from the unitarity problem. For bouncing and emergent cosmologies, no constraints arise provided that the energy scale of the bounce or emergent phases is smaller than the ultraviolet (UV) cutoff scale. On the other hand, in the case of the inflationary scenario, non-trivial upper bounds on the energy scale of inflation arise.

    ↳ hep-thastro-ph.COgr-qchep-phEPJC(2022)·22 citations
21. 21*

    Multicomponent relativistic dissipative fluid dynamics from the Boltzmann equation

    Jan A. Fotakis🇩🇪 · Etele Molnár🇩🇪 · Harri Niemi🇫🇮 · Carsten Greiner🇩🇪 · Dirk H. Rischke🇩🇪

    We derive multicomponent relativistic second-order dissipative fluid dynamics from the Boltzmann equations for a reactive mixture of $N_{\text{spec}}$ particle species with $N_q$ intrinsic quantum numbers (e.g. electric charge, baryon number, and strangeness) using the method of moments. We obtain the continuity equations for multiple conserved charges as well as the conservation equations for the total energy and momentum in the single-fluid approximation. These $4+N_q$ conservation laws are closed by deriving the second-order equations of motion for the dissipative quantities in the $(10+4N_q)$-moment approximation. The resulting fluid-dynamical equations are formally similar to those of a single-component system, but feature different thermodynamic relations and transport coefficients. We derive general relations for all transport coefficients and compute them explicitly in the ultrarelativistic limit.

    ↳ nucl-thhep-phphysics.flu-dynPRD(2022)·54 citations
22. 22*

    Probing Higgs $CP$ properties at the CEPC

    Qiyu Sha · Abdualazem Fadol · Fangyi Guo · Gang Li · Jiayin Gu · Xinchou Lou · Yaquan Fang

    In the Circular Electron Positron Collider (CEPC), a measurement of the Higgs CP mixing through $e^{+}{e}^{-}\to ZH\to l^{+}{l}^{-}(e^{+}{e}^{-}/{\mu }^{+}{\mu }^{-})H(\to b\bar{b}/c\bar{c}/gg)$ process is presented, with $5.6\text{mbox}{ab}^{-1}$ $e^{+}{e}^{-}$ collision data at the center-of-mass energy of $240\mathrm{GeV}$. In this study, the CP-violating parameter ${\tilde{c}}_{Z\gamma }$ is constrained between the region of $-0.30$ and $0.27$ and ${\tilde{c}}_{ZZ}$ between $-0.06$ and $0.06$ at $68\%$ confidence level. This study demonstrates the great potential of probing Higgs $CP$ properties at the CEPC.

    ↳ hep-exhep-phEPJC(2022)·18 citations
23. 23*

    Lattice QCD study of inclusive semileptonic decays of heavy mesons

    Paolo Gambino🇮🇹 · Shoji Hashimoto🇯🇵 · Sandro Mächler🇮🇹 · Marco Panero🇮🇹 · Francesco Sanfilippo🇮🇹 · Silvano Simula🇮🇹 · Antonio Smecca🇮🇹 · Nazario Tantalo🇮🇹

    We present an ab initio study of inclusive semileptonic decays of heavy mesons from lattice QCD. Our approach is based on a recently proposed method, that allows one to address the study of these decays from the analysis of smeared spectral functions extracted from four-point correlators on the lattice, where the smearing is defined in terms of the phase-space integration relevant to the inclusive decays. We present results obtained from gauge-field ensembles from the JLQCD and ETM collaborations, and discuss their relation with theoretical predictions from the operator-product expansion.

    ↳ hep-lathep-phJHEP(2022)·87 citations
24. 24*

    Constraining the Gravitational-Wave Spectrum from Cosmological First-Order Phase Transitions Using Data from LIGO-Virgo First Three Observing Runs

    Yang Jiang🇨🇳 · Qing-Guo Huang🇨🇳

    We search for a first-order phase transition (PT) gravitational wave (GW) signal from Advanced LIGO and Advanced Virgo's first three observing runs. Due to the large theoretical uncertainties, four GW energy spectral shapes from bubble and sound wave collisions widely adopted in literature are investigated, separately. Our results indicate that there is no evidence for the existence of such GW signals, and therefore we give the upper limits on the amplitude of GW energy spectrum ${\Omega }_{\text{pt}}(f_{\ast })$ in the peak frequency range of $f_{\ast }\in [5,500]$ Hz for these four theoretical models, separately. We find that ${\Omega }_{\text{pt}}(f_{\ast }\simeq 40\text{Hz})<1.3\times 10^{-8}$ at $95\%$ credible level, and roughly $H_{\ast }/\beta \lesssim 0.1$ and $\alpha \lesssim 1$ at $68\%$ credible level in the peak frequency range of $20\lesssim f_{\ast }\lesssim 100$ Hz corresponding to the most sensitive frequency band of Advanced LIGO and Advanced Virgo's first three observing runs, where $H_{\ast }$ is the Hubble parameter when PT happens, $\beta$ is the bubble nucleation rate and $\alpha$ is the ratio of vacuum and relativistic energy density.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2023)·11 citations
25. 25*

    Snowmass 2021 White Paper: Tabletop experiments for infrared quantum gravity

    Daniel Carney🇺🇸 · Yanbei Chen🇺🇸 · Andrew Geraci🇺🇸 · Holger Müller🇺🇸 · Cristian D. Panda🇺🇸 · Philip C. E. Stamp🇨🇦 · Jacob M. Taylor🇺🇸

    Progress in the quantum readout and control of mechanical devices from single atoms to large masses may enable a first generation of experiments probing the gravitational interaction in the quantum regime, conceivably within the next decade. In this Snowmass whitepaper, we briefly outline the possibilities and challenges facing the realization of these experiments. In particular, we emphasize the need for detailed theories of modifications to the usual effective QFT of gravitons in the infrared regime $E/L^3\ll m_{\mathrm{Pl}}/{\ell }_{\mathrm{Pl}}^3$ in which these experiments operate, and relations to possible UV completions.

    ↳ gr-qchep-phquant-ph18 citations
26. 26*

    Small-scale structure in vector dark matter

    Mustafa A. Amin🇺🇸 · Mudit Jain🇺🇸 · Rohith Karur🇺🇸 · Philip Mocz🇺🇸

    We investigate the differences in the small-scale structure of vector dark matter (VDM) and scalar dark matter (SDM) using 3+1 dimensional simulations of single/multicomponent Schrödinger-Poisson system. We find that the amount of wave interference, core-to-halo mass ratio (and its scatter), spin of the core, as well as the shape of the central regions of dark matter halos can distinguish VDM and SDM. Starting with a collection of idealized halos (self-gravitating solitons) as an initial condition, we show that the system dynamically evolves to an approximately spherically symmetric configuration that has a core surrounded by a halo of interference patterns in the mass density. In the vector case, the central soliton in less dense and has a smoother transition to an $r^{-3}$ tail compared to the scalar case. As compared to SDM, wave interference in VDM is $\sim 1/\sqrt{3}$ times smaller, resulting in fewer low and high density regions, and more diffuse granules in the halo. The ratio of VDM core mass to the total halo mass is lower than that in SDM, with a steeper dependence on the total energy of the system and a slightly larger scatter. Finally, we also initiate a study of the evolution of intrinsic spin angular momentum in the VDM case. We see a positive correlation between the total intrinsic spin in the simulation and the spin of the final central core, with significant scatter. We see large intrinsic spin in the core being possible even with vanishing amounts total angular momentum in the initial conditions (at least instantaneously). Our results point towards the possibility of distinguishing VDM from SDM using astrophysical and terrestrial observations.

    ↳ astro-ph.COhep-phJCAP(2022)·109 citations
27. 27*

    High-Energy Extragalactic Neutrino Astrophysics

    Naoko Kurahashi🇺🇸 · Kohta Murase🇺🇸 · Marcos Santander🇺🇸

    The detection of an astrophysical flux of neutrinos in the TeV-PeV energy range by the IceCube observatory has opened new possibilities for the study of extreme cosmic accelerators. The apparent isotropy of the neutrino arrival directions favors an extragalactic origin for this flux, potentially created by a large population of distant sources. Recent evidence for the detection of neutrino emission from extragalactic sources include the active galaxies TXS 0506+056 and NGC 1068. We here review the current status of the search for the sources of the high-energy neutrino flux, concentrating on its extragalactic contribution. We discuss the implications of these observations for multimessenger studies of cosmic sources and present an outlook for how additional observations by current and future instruments will help address fundamental questions in the emerging field of high-energy neutrino astronomy.

    ↳ astro-ph.HEastro-ph.COhep-phAnn.Rev.Nucl.Part.Sci.(2022)·58 citations
28. 28*

    Bootstrapping Pions at Large $N$

    Jan Albert🇺🇸 · Leonardo Rastelli🇺🇸

    We revisit from a modern bootstrap perspective the longstanding problem of solving QCD in the large $N$ limit. We derive universal bounds on the effective field theory of massless pions by imposing the full set of positivity constraints that follow from $2\to 2$ scattering. Some features of our exclusion plots have intriguing connections with hadronic phenomenology. The exclusion boundary exhibits a sharp kink, raising the tantalizing scenario that large $N$ QCD may sit at this kink. We critically examine this possibility, developing in the process a partial analytic understanding of the geometry of the bounds.

    ↳ hep-thhep-phJHEP(2022)·99 citations
29. 29*

    Deconfinement Temperature of Rotating QGP at Intermediate Coupling from $\mathcal{M}$-Theory

    Gopal Yadav🇮🇳

    With the aim of studying rotating quark-gluon plasma (QGP), holographically, from a top-down approach, the study of the effect of rotation on the deconfinement temperature of thermal QCD-like theories at intermediate coupling from $\mathcal{M}$-theory was missing in the literature. This paper fills this gap. The gravity dual includes a rotating cylindrical black hole. In the presence of rotation, from a semi-classical computation, we found that the deconfinement temperature is inversely proportional to the Lorentz factor, which suggests that the deconfinement temperature decreases with the increase of rotation. Further, we found that in the small angular velocity limit, results from higher derivative correction at $\mathcal{O}(R^4)$ do not change and are the same as in arXiv:2108.05372. The "UV-IR mixing", "Flavor Memory" effect, and "non-renormalization of $T_c$" in the $\mathcal{M}$-theory dual are similar to the ones observed in arXiv:2108.05372.

    ↳ hep-thhep-phPLB(2023)·30 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.