HEP Phenomenology·hep-ph

Thu·Aug 6, 2020Thursday·August 6, 2020

17 papers—10 primary·7 cross-listed·reconstructed*

01*
Calculation of transverse momentum dependent distributions beyond the leading power
Valentin Moos🇩🇪 · Alexey Vladimirov🇩🇪
We compute the contribution of twist-2 and twist-3 parton distribution functions to the small- $b$ expansion for transverse momentum dependent (TMD) distributions at all powers of $b$ . The computation is done by the twist-decomposition method based on the spinor formalism for all eight quark TMD distributions. The newly computed terms are accompanied by the prefactor $(M^{2} b^{2})^{n}$ and represent the target-mass corrections to the resummed cross-section. For the first time, a non-trivial expression for the pretzelosity distribution is derived.
hep-phhep-thJHEP(2020)·38 citations
02*
About the $J / ψ J / ψ$ peak of LHCb: fully-charmed tetraquark?
Jean-Marc Richard🇫🇷
We discuss the interpretation of the $J / ψ J / ψ$ peak recently seen by the LHCb collaboration at CERN, and take the opportunity to review the experimental and theoretical state of the art for exotic hadrons. It is stressed that in constituent models, the states in the continuum require a dedicated treatment to single out resonances atop the continuum.
hep-phSci.Bull.(2020)·48 citations
03*
Semileptonic and nonleptonic decays of the axial-vector tetraquark $T_{bb; u d}^{-}$
S. S. Agaev🇦🇿 · K. Azizi🇮🇷 · B. Barsbay🇹🇷 · H. Sundu🇹🇷
The semileptonic and nonleptonic decays of the double-beauty axial-vector tetraquark $T_{bb; u d}^{-}$ to a state $T_{b c; u d}^{0}$ (hereafter $T_{bb}^{-}$ and $T_{b c}^{0}$ , respectively) are investigated in the context of the QCD sum rule method. The final-state tetraquark $T_{b c}^{0}$ is treated as an axial-vector particle built of a heavy axial-vector diquark $b^{T} γ_{μ} C c$ and light scalar antidiquark $u C γ_{5} d^{T}$ . Its spectroscopic parameters are calculated using the two-points sum rules by taking into account contributions of quark, gluon and mixed condensates up to dimension $10$ . We study the dominant semileptonic $T_{bb}^{-} \to T_{b c}^{0} l ν_{l}$ and nonleptonic decays $T_{bb}^{-} \to T_{b c}^{0} M$ , where $M$ is one of the pseudoscalar mesons $π^{-}, K^{-}, D^{-}$ and $D_{s}^{-}$ . The partial widths of these processes are computed in terms of weak form factors $G_{i} (q^{2}), i = 1, 2, 3, 4$ , extracted by employing the QCD three-point sum rule approach. Predictions obtained for partial widths of considered decays are used to improve accuracy of theoretical predictions for full width and lifetime of the tetraquark $T_{bb}^{-}$ , which are important for experimental exploration of this exotic meson.
hep-phhep-exhep-latEPJA(2021)·22 citations
04*
Methodology for measuring gluon jet fraction and characteristics of quark and gluon jets for hadron-hadron collisions
S. Shulha🇷🇺 · D. Budkouski🇷🇺
The discriminators of quark-gluon jets developed for $pp$ collisions at the LHC can be used to measure the gluon jet fraction in a jet sample. It allows to measure various characteristics of the quark and gluon jets. The methodology of such measurements for modern hadron colliders is discussed.
hep-phPhys.Part.Nucl.Lett.(2021)·4 citations
05*
Neutrino mixing and Leptogenesis with modular $S_{3}$ symmetry in the framework of type III seesaw
Subhasmita Mishra🇮🇳
Discrete symmetries being preferred to explain the neutrino phenomenology, we chose the simplest $S_{3}$ group and explore the implication of its modular form on neutrino masses and mixing. Non-trivial transformations of Yukawa couplings under this symmetry, make the model phenomenologically interesting by reducing the requirement of multiple scalar fields. This symmetry imposes a specific flavor structure to the neutrino mass matrix within the framework of less frequented type III seesaw mechanism and helps to explore the neutrino mixing consistent with the current observation. Apart, we also explain the preferred scenario of leptogenesis to explain the baryon asymmetry of the universe by generating the lepton asymmetry from the decay of heavy fermion triplet at TeV scale.
hep-ph49 citations
06*
Constraining hidden photons via atomic force microscope measurements and the Plimpton-Lawton experiment
D. Kroff🇧🇷 · P.C. Malta🇧🇷
Modifications to electrodynamics from physics beyond the Standard Model can be tested to a high accuracy. Here we use two setups to place bounds on hidden photons, an Abelian boson kinetically mixed with the photon. The first setup involves atomic force microscope measurements, originally designed to study the Casimir effect at sub- $μ$ m distances. The second setup consists of two concentric metal shells with the outer one exposed to a high voltage. By measuring the potential difference between the shells it is possible to test Coulomb's law. The limits obtained here cover regions already excluded, in particular by astrophysical observations, but provide a more direct, laboratory-based confirmation of these bounds.
hep-phhep-exPRD(2020)·31 citations
07*
Cosmological Tension of Ultralight Axion Dark Matter and its Solutions
Jeff A. Dror🇺🇸 · Jacob M. Leedom🇺🇸
A number of proposed and ongoing experiments search for axion dark matter with a mass nearing the limit set by small scale structure ( $O (1 0^{- 21} eV)$ ). We consider the late universe cosmology of these models, showing that requiring the axion to have a matter-power spectrum that matches that of cold dark matter constrains the magnitude of the axion couplings to the visible sector. Comparing these limits to current and future experimental efforts, we find that many searches require axions with an abnormally large coupling to Standard Model fields, independently of how the axion was populated in the early universe. We survey mechanisms that can alleviate the bounds, namely, the introduction of large charges, various forms of kinetic mixing, a clockwork structure, and imposing a discrete symmetry. We provide an explicit model for each case and explore their phenomenology and viability to produce detectable ultralight axion dark matter.
hep-phastro-ph.COhep-exPRD(2020)·33 citations
08*
General relativity and precision tests of fundamental symmetries
N.N. Nikolaev🇷🇺 · S.N. Vergeles🇷🇺
Search for the Electric Dipole Moment of nuclear particles is at the forefront of incessant quest for CP violation beyond Standard Model. The ultimate target is to reach a sensitivity to the electric dipole moment of neutrons, protons, deuterons etc. at the level of $\sim 1 0^{- 15}$ nuclear magnetons. Defying the common lore on weakness of gravity, spurious signals induced by curved space-time in the gravity field of the rotating Earth become quite substantial at such a daunting sensitivity. We review the recent development in the field with an emphasis on the geometric magnetic field in pure electrostatic systems at rest on the rotating Earth.
hep-ph0 citations
09*
A two-loop induced neutrino mass model, dark matter, and LFV processes $ℓ_{i} \to ℓ_{j} γ$ , and $μ e \to ee$ in a hidden local $U (1)$ symmetry
Takaaki Nomura🇰🇷 · Hiroshi Okada🇰🇷 · Yuichi Uesaka🇯🇵
We discuss a model based on a hidden $U (1)_{X}$ gauge symmetry in which neutrino mass is induced at two-loop level by effects of interactions among particles in hidden sector and the Standard Model leptons. Since neutrino mass is suppressed by two-loop, its associate Yukawa couplings can be sizable and it would affect lepton flavor phenomenology. We analyze neutrino mass matrix, lepton flavor violating processes, electron/muon $g - 2$ and dark matter annihilation cross section which are induced via interactions among Standard Model leptons and particles in $U (1)_{X}$ hidden sector, and their interactions can be sizable in our scenario. Performing numerical analysis, we show expected ratios for these processes using allowed parameters which can fit the neutrino data and satisfy flavor constraints.
hep-phNPB(2021)·14 citations
10*
Neutron star structure with nuclear force mediated by hypothetical X17 boson
Vlasios Petousis🇨🇿 · Martin Veselsky🇨🇿 · Jozef Leja🇸🇰
A reported $17$ MeV boson, which has been proposed as an explanation to the $^{8}$ Be and $^{4}$ He anomaly, is investigated in the context of its possible influence to neutron stars structure. Implementing a $m_{X}$ =17 MeV to the nuclear equation of state using different incompressibility values K $_{0}$ =245 MeV and K $_{0}$ =260 MeV and solving Tolman-Oppenheimer-Volkoff equations, we estimate an upper limit of $M_{T O V} \approx 2.4 M ⊙$ for a non rotating neutron star with span in radius $R$ between $11.5$ km to $14$ km. Moving away from pure - NN with admixture of 10\% protons and simulating possible softening of equation of state due to hyperons, we see that our estimated limits fit quite well inside the newest reported studies, coming from neutron stars merger event, GW190814
hep-phnucl-thEPJ Web Conf.(2021)·5 citations
11*
Double layer from least action principle
V. A. Berezin🇷🇺 · V. I. Dokuchaev🇷🇺 · Yu. N. Eroshenko🇷🇺 · A. L. Smirnov🇷🇺
We derived the equations for the double layers in Quadratic Gravity, using solely the least action principle. The advantage of our approach is that, in the process of calculation, the $δ^{'}$ -function does not appear at all, and the $δ$ -functions appear for a moment and are mutually canceled prior to integration. We revealed the peculiar structure of the obtained equations, namely, that the surface energy-momentum tensor of the matter fields (constituents of the thin shells) does not play a role in the determination of the trajectory of the double layer. Also, we suggested that the space-like double layers may provide us with the adequate description of the creation of the universe from the black hole singularity. The related topics, including the Gauss-Bonnet term and $F (R)$ -theories, are shortly discussed.
↳ gr-qchep-phClass.Quant.Grav.(2021)·12 citations
12*
Bubble wall correlations in cosmological phase transitions
Ariel Megevand🇦🇷 · Federico Agustin Membiela🇦🇷
We study statistical relationships between bubble walls in cosmological first-order phase transitions. We consider the conditional and joint probabilities for different points on the walls to remain uncollided at given times. We use these results to discuss space and time correlations of bubble walls and their relevance for the consequences of the transition. In our statistical treatment, the kinematics of bubble nucleation and growth is characterized by the nucleation rate and the wall velocity as functions of time. We obtain general expressions in terms of these two quantities, and we consider several specific examples and applications.
↳ astro-ph.COhep-phPRD(2020)·6 citations
13*
Renormalisation of the tensor current in lattice QCD and the $J / ψ$ tensor decay constant
D. Hatton🇬🇧 · C. T. H. Davies🇬🇧 · G. P. Lepage🇺🇸 · A. T. Lytle🇮🇹
Lattice QCD calculations of form factors for rare Standard Model processes such as $B \to K ℓ^{+} ℓ^{-}$ use tensor currents that require renormalisation. These renormalisation factors, $Z_{T}$ , have typically been calculated within perturbation theory and the estimated uncertainties from missing higher order terms are significant. Here we study tensor current renormalisation using lattice implementations of momentum-subtraction schemes. Such schemes are potentially more accurate but have systematic errors from nonperturbative artefacts. To determine and remove these condensate contributions we calculate the ground-state charmonium tensor decay constant, $f_{J / ψ}^{T}$ , which is also of interest in beyond the Standard Model studies. We obtain $f_{J / ψ}^{T} (MS ˉ, 2 GeV) = 0.3927 (27)$ GeV, with ratio to the vector decay constant of 0.9569(52), significantly below 1. We also give $Z_{T}$ factors, converted to the $MS ˉ$ scheme, corrected for condensate contamination. This contamination reaches 1.5\% at a renormalisation scale of 2 GeV (in the preferred RI-SMOM scheme) and so must be removed for accurate results.
↳ hep-lathep-phPRD(2020)·27 citations
14*
String Memories ... Lost and Regained
Andrea Addazi🇨🇳 · Massimo Bianchi🇮🇹 · Maurizio Firrotta🇮🇹 · Antonino Marcianò🇨🇳
We discuss stringy $α^{'}$ corrections to the gravitational wave signal generated in the merging of two black holes. We model the merging with two BPS compact massive objects in the heterotic string, described by standard vertex operators or coherent states. Despite the expected cubic suppression in $α^{'}$ w.r.t. the General Relativity result, at tree level the string corrections seem to leave a footprint or a memory on the gravitational wave signals within the sensitivity region of aLIGO/VIRGO and future interferometers. Including loop effects that broaden and destabilise the string resonances suggests a sort of lost stringy memory effect that can be regained through the analysis of the quasi normal modes in the ring-down phase.
↳ hep-thgr-qchep-phNPB(2021)·17 citations
15*
Non-vanishing normal density in cold holographic superfluids
Blaise Goutéraux🇫🇷 · Eric Mefford🇫🇷
The low energy and finite temperature excitations of a $d + 1$ -dimensional system exhibiting superfluidity are well described by a hydrodynamic model with two fluid flows: a normal flow and a superfluid flow. In the vicinity of a quantum critical point, thermodynamics and transport in the system are expected to be controlled by the critical exponents and by the spectrum of irrelevant deformations away from the quantum critical point. Here, using gauge-gravity duality, we present the low temperature dependence of thermodynamic and charge transport coefficients at first order in the hydrodynamic derivative expansion in terms of the critical exponents. Special attention will be paid to the behavior of the charge density of the normal flow in systems with emergent infrared conformal and Lifshitz symmetries, parameterized by a Lifshitz dynamical exponent $z > 1$ . When $1 \leq z < d + 2$ , we recover ( $z = 1$ ) and extend ( $z > 1$ ) previous results obtained by relativistic effective field theory techniques. Instead, when $z > d + 2$ , we show that the normal charge density becomes non-vanishing at zero temperature. An extended appendix generalizes these results to systems that violate hyperscaling as well as systems with generalized photon masses. Our results clarify previous work in the holographic literature and have relevance to recent experimental measurements of the superfluid density on cuprate superconductors.
↳ hep-thcond-mat.quant-gascond-mat.str-elcond-mat.supr-con+1JHEP(2020)·10 citations
16*
Analog cosmological reheating in an ultracold Bose gas
Aleksandr Chatrchyan🇩🇪 · Kevin T. Geier🇩🇪 · Markus K. Oberthaler🇩🇪 · Jürgen Berges🇩🇪 · Philipp Hauke🇮🇹
Cosmological reheating describes the transition of the post-inflationary universe to a hot and thermal state. In order to shed light on the underlying dynamics of this process, we propose to quantum-simulate the reheating-like dynamics of a generic cosmological single-field model in an ultracold Bose gas. In our setup, the excitations on top of an atomic Bose-Einstein condensate play the role of the particles produced by the decaying inflaton field after inflation. Expanding spacetime as well as the background oscillating inflaton field are mimicked in the non-relativistic limit by a time dependence of the atomic interactions, which can be tuned experimentally via Feshbach resonances. As we illustrate by means of classical-statistical simulations for the case of two spatial dimensions, the dynamics of the atomic system exhibits the characteristic stages of far-from-equilibrium reheating, including the amplification of fluctuations via parametric instabilities and the subsequent turbulent transport of energy towards higher momenta. The transport is governed by a non-thermal fixed point showing universal self-similar time evolution as well as a transient regime of prescaling with time-dependent scaling exponents. While the classical-statistical simulations can capture only the earlier stages of the dynamics for weak couplings, the proposed experiment has the potential of exploring the evolution up to late times even beyond the weak coupling regime.
↳ cond-mat.quant-gashep-phquant-phPRA(2021)·43 citations
17*
Replica evolution of classical field in 4+1 dimensional spacetime toward real time dynamics of quantum field
Akira Ohnishi (1)🇯🇵 · Hidefumi Matsuda (2)🇯🇵 · Teiji Kunihiro (1)🇯🇵 · Toru T. Takahashi (3) ((1) Yukawa Institute for Theoretical Physics, Kyoto University, (2) Department of Physics, Faculty of Science, Kyoto University, (3) National Institute of Technology, Gunma college)🇯🇵
Real-time evolution of replicas of classical field is proposed as an approximate simulator of real-time quantum field dynamics at finite temperatures. We consider $N$ classical field configurations dubbed as replicas which interact with each other via the $τ$ -derivative terms and evolve with the classical equation of motion. The partition function of replicas is found to be proportional to that of quantum field in the imaginary time formalism. As the replica index $τ$ can be regarded as the imaginary time index, the replica evolution is technically the same as the molecular dynamics part of the hybrid Monte-Carlo sampling and the replica configurations should reproduce the correct quantum equilibrium distribution after the long-time evolution. At the same time, evolution of the replica-index average of field variables is described by the classical equation of motion when the fluctuations are small. In order to examine the real-time propagation properties of replicas, we first discuss replica evolution in quantum mechanics. Statistical averages of observables are precisely obtained by the initial condition average of replica evolution, and the time evolution of the unequal-time correlation function, $⟨ x (t) x (t^{'})⟩$ , in a harmonic oscillator is also described well by the replica evolution in the range $T / ω > 0.5$ . Next, we examine the statistical and dynamical properties of the $ϕ^{4}$ theory in the 4+1 dimensional spacetime, which contains three spatial, one replica index or the imaginary time, and one real-time. We note that the Rayleigh-Jeans divergence can be removed in replica evolution with $N \geq 2$ when the mass counterterm is taken into account. We also find that the thermal mass obtained from the unequal-time correlation function at zero momentum grows as a function of the coupling as in the perturbative estimate in the small coupling region.
↳ hep-lathep-phhep-thPTEP(2021)·1 citation

* 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.