Thu·Aug 25, 2022Thursday·August 25, 2022

1. 01*

   Reheating with Effective Potentials

   S. Katuwal (U. Florida)🇺🇸 · S. P. Miao (NCKU, Taiwan)🇹🇼 · R. P. Woodard (U. Florida)🇺🇸

   We consider reheating for a charged inflaton which is minimally coupled to electromagnetism. The evolution of such an inflaton induces a time-dependent mass for the photon. We show how the massive photon propagator can be expressed as a spatial Fourier mode sum involving three different sorts of mode functions, just like the constant mass case. We develop accurate analytic approximations for these mode functions, and use them to approximate the effective force exerted on the inflaton $0$-mode. This effective force allows one to simply compute the evolution of the inflaton $0$-mode and to follow the progress of reheating.

   hep-phastro-ph.COgr-qchep-thJCAP(2022)·5 citations
2. 02*

   WIMPy Leptogenesis in Non-Standard Cosmologies

   Devabrat Mahanta🇮🇳 · Debasish Borah🇮🇳

   We study the possibility of generating baryon asymmetry of the universe from dark matter (DM) annihilations during non-standard cosmological epochs. Considering the DM to be of weakly interacting massive particle (WIMP) type, the generation of baryon asymmetry via leptogenesis route is studied where WIMP DM annihilation produces a non-zero lepton asymmetry. Adopting a minimal particle physics model to realise this along with non-zero light neutrino masses, we consider three different types of non-standard cosmic history namely, (i) fast expanding universe, (ii) early matter domination and (iii) scalar-tensor theory of gravity. By solving the appropriate Boltzmann equations incorporating such non-standard history, we find that the allowed parameter space consistent with DM relic and observed baryon asymmetry gets enlarged with the possibility of lower DM mass in some scenarios. While such lighter DM can face further scrutiny at direct search experiments, the non-standard epochs offer complementary probes on their own.

   hep-phastro-ph.COJCAP(2023)·18 citations
3. 03*

   Vacuum stability of the type II seesaw leptogenesis from inflation

   Chengcheng Han🇨🇳 · Sihui Huang🇨🇳 · Zhanhong Lei🇨🇳

   Recently it has been found that introducing a triplet Higgs to the standard model could provide a feasible leptogenesis to generate the baryon asymmetry of our universe, providing that the inflation is driven by the mixing state of the triplet Higgs and SM Higgs. In this work, we survey the viable parameter space satisfying the vacuum stability and perturbativity in this model. We find that the introduction of the triplet Higgs would also ameliorate the problem of the Higgs vacuum instability. We present two representative parameter regions where the origin of neutrino masses, baryon asymmetry of the universe as well as inflation can be explained while keeping consistent with the condition of vacuum stability and perturbativity.

   hep-phPRD(2023)·11 citations
4. 04*

   Running of the top quark mass at NNLO in QCD

   Matteo M. Defranchis🇨🇭 · Jan Kieseler🇨🇭 · Katerina Lipka🇩🇪 · Javier Mazzitelli🇩🇪

   The running of the top quark mass ($m_{\mathrm{t}}$) is probed at the next-to-next-to-leading order in quantum chromodynamics for the first time. The result is obtained by comparing calculations in the modified minimal subtraction ($\overline{\mathrm{MS}}$) renormalisation scheme to the CMS result on differential measurement of the top quark-antiquark ($\mathrm{t}\bar{\mathrm{t}}$) production cross section at $\sqrt{s}=13\mathrm{TeV}$. The scale dependence of $m_{\mathrm{t}}$ is extracted as a function of the invariant mass of the $\mathrm{t}\bar{\mathrm{t}}$ system, up to an energy scale of about $0.5\mathrm{TeV}$. The observed running is found to be in good agreement with the three-loop solution of the renormalisation group equations of quantum chromodynamics.

   hep-phhep-exJHEP(2024)·14 citations
5. 05*

   Impact of Lorentz violation on anomalous magnetic moments of charged leptons

   Andreas Crivellin🇨🇭 · Fiona Kirk🇨🇭 · Marco Schreck🇧🇷

   We address the question whether a violation of Lorentz symmetry can explain the tension between the measurement and the Standard-Model prediction of the anomalous magnetic moment of the muon ($(g-2{)}_{\mu }$) and whether it can significantly impact the one of the electron ($(g-2{)}_e$). While anisotropic Lorentz-violating effects are, in general, expected to produce sidereal oscillations in observables, isotropic Lorentz violation in the charged-lepton sector could feed into $(g-2{)}_{e,\mu }$. However, we find that this type of Lorentz violation, parametrised via a dim-4 field operator of the Standard-Model Extension (SME), is already strongly constrained by the absence of vacuum Čerenkov radiation and photon decay. In particular, the observations of very-high-energetic astrophysical photons at LHAASO and of high-energetic electrons (muons) by the LHC (IceCube) place the most stringent two-sided bounds on the relevant SME coefficients $\stackrel{\circ }{c}{}^{(e)}$ ($\stackrel{\circ }{c}{}^{(\mu )}$). Therefore, any explanation of the tension in $(g-2{)}_{\mu }$ via isotropic Lorentz violation of the minimal spin-degenerate SME is excluded, and the possible size of its impact on $(g-2{)}_e$ is very limited.

   hep-phhep-thJHEP(2022)·17 citations
6. 06*

   Baryon density and magnetic field effects on chaos in a $Q\bar{Q}$ system at finite temperature

   N. Losacco🇮🇹

   Baryon density and magnetic field effect on chaos for the holographic dual of a $Q\bar{Q}$ system at finite temperature is studied. A string in an AdS Reissner Nordstrom background, and in a metric with magnetic field near the black hole horizon is considered and small time-dependent perturbations of the static configurations are investigated. The proximity to the horizon induces chaos, which is softened increasing the chemical potential or the magnetic field. A background geometry including the effect of a dilaton is also examined. The Maldacena, Shenker, and Stanford bound on the Lyapunov exponents characterizing the perturbations is satisfied for finite baryon chemical potential and magnetic field and when the dilaton is included in the metric.

   hep-phJHAP(2022)·2 citations
7. 07*

   Production of $e^{+}{e}^{-}$ in proton-lead collision: photon-photon fusion

   Barbara Linek🇵🇱 · Marta Łuszczak🇵🇱 · Wolfgang Schäfer🇵🇱 · Antoni Szczurek🇵🇱

   We analyze the photon-initiated processes for production of $e^{+}{e}^{-}$ pairs in proton-nucleus collisions at LHC energy, taking into account both elastic processes and proton dissociations in the low-mass region (LMR) and intermediate-mass region (IMR) as defined by the ALICE collaboration. The calculations are performed within the $k_{\mathrm{T}}$-factorisation approach, including transverse momenta of intermediate photons. We discuss several differential distributions in invariant mass of both the leptons $M_{ll}$, pair rapidity $Y_{ll}$ and transverse momenta of the lepton pair $p_{t,ll}$. In addition, we present the two-dimensional distributions in ${\log }_{10}{x}_{Bj}$ and ${\log }_{10}{Q}^2$ and (${\log }_{10}W,{\log }_{10}{Q}^2$) the arguments of the deep-inelastic structure functions. All presented results were obtained with modern parametrizations of proton structure functions. Limiting to small invariant masses of dielectrons one tests structure functions in the nonperturbative region of small $Q^2$ and/or small $W$. We quantify difference for different parametrizations from the literature.

   hep-phPRD(2022)·3 citations
8. 08*

   Scrutinizing CKM unitarity with a new measurement of the $K_{\mu 3}/K_{\mu 2}$ branching fraction

   Vincenzo Cirigliano🇺🇸 · Andreas Crivellin🇨🇭 · Martin Hoferichter🇨🇭 · Matthew Moulson🇨🇭

   Precision tests of first-row unitarity of the Cabibbo-Kobayashi-Maskawa matrix currently display two intriguing tensions, both at the $3\sigma$ level. First, combining determinations of $V_{ud}$ from superallowed $\beta$ decays with $V_{us}$ from kaon decays suggests a deficit in the unitarity relation. At the same time, a tension of similar significance has emerged between $K_{\ell 2}$ and $K_{\ell 3}$ decays. In this Letter, we point out that a measurement of the $K_{\mu 3}/K_{\mu 2}$ branching fraction at the level of $0.2\%$ would have considerable impact on clarifying the experimental situation in the kaon sector, especially in view of tensions in the global fit to kaon data as well as the fact that the $K_{\mu 2}$ channel is currently dominated by a single experiment. Such a measurement, as possible for example at NA62, would further provide important constraints on physics beyond the Standard Model, most notably on the role of right-handed vector currents.

   hep-phhep-exhep-latnucl-thPLB(2023)·115 citations
9. 09*

   Cascades of high-energy SM particles in the primordial thermal plasma

   Kyohei Mukaida🇯🇵 · Masaki Yamada🇯🇵

   High-energy standard model (SM) particles in the early Universe are generated by the decay of heavy long-lived particles. The subsequent thermalization occurs through the splitting of high-energy primary particles into lower-energy daughters in primordial thermal plasma. The principal example of such processes is reheating after inflation caused by the decay of inflatons into SM particles. Understanding of the thermalization at reheating is extremely important as it reveals the origin of the hot Universe, and could open up new mechanisms for generating dark matter and/or baryon asymmetry. In this paper, we investigate the thermalization of high-energy SM particles in thermal plasma, taking into account the Landau--Pomeranchuk--Migdal effect in the leading-log approximation. The whole SM particle content and all the relevant SM interactions are included for the first time, i.e., the full gauge interactions of SU(3)${}_c\times$SU(2)${}_L\times$U(1)${}_Y$ and the top Yukawa interaction. The distribution function of each SM species is computed both numerically and analytically. We have analytically obtained the distribution function of each SM species after the first few splittings. Furthermore, we demonstrate that, after a sufficient number of splittings, the particle distributions are asymptotic to certain values at low momentum, independent of the high-energy particles injected by inflaton decay. The results are useful to calculate the DM abundance produced during the pre-thermal phase. An example is provided to illustrate a way to calculate the DM abundance from the scattering between the thermal plasma and high-energy particles in the cascade.

   hep-phastro-ph.COJHEP(2022)·32 citations
10. 10*

    A reanalysis of the latest SH0ES data for $H_0$: Effects of new degrees of freedom on the Hubble tension

    Leandros Perivolaropoulos🇬🇷 · Foteini Skara🇬🇷

    We reanalyze the recently released SH0ES data for the determination of $H_0$. We focus on testing the homogeneity of the Cepheid+SnIa sample and the robustness of the results in the presence of new degrees of freedom in the modeling of Cepheids and SnIa. We thus focus on the four modeling parameters of the analysis: the fiducial luminosity of SnIa $M_B$ and Cepheids $M_W$ and the two parameters ($b_W$ and $Z_W$) standardizing Cepheid luminosities with period and metallicity. After reproducing the SH0ES baseline model results, we allow for a transition of the value of any one of these parameters at a given distance $D_c$ or cosmic time $t_c$ thus adding a single degree of freedom in the analysis. When the SnIa absolute magnitude $M_B$ is allowed to have a transition at $D_c\simeq 50Mpc$ (about $160Myrs$ ago), the best fit value of the Hubble parameter drops from $H_0=73.04\pm 1.04km{s}^{-1}Mp{c}^{-1}$ to $H_0=67.32\pm 4.64km{s}^{-1}Mp{c}^{-1}$ in full consistency with the Planck value. Also, the best fit SnIa absolute magnitude $M_B^{>}$ for $D>D_c$ drops to the Planck inverse distance ladder value $M_B^{>}=-19.43\pm 0.15$ while the low distance best fit $M_B^{<}$ parameter remains close to the original distance ladder calibrated value $M_B^{<}=-19.25\pm 0.03$. Similar hints for a transition behavior is found for the other three main parameters of the analysis ($b_W$, $M_W$ and $Z_W$) at the same critical distance $D_c\simeq 50Mpc$ even though in that case the best fit value of $H_0$ is not significantly affected. When the inverse distance ladder constraint on $M_B^{>}$ is included in the analysis, the uncertainties for $H_0$ reduce dramatically ($H_0=68.2\pm 0.8km{s}^{-1}Mp{c}^{-1}$) and the $M_B$ transition model is strongly preferred over the baseline SH0ES model ($\Delta {\chi }^2\simeq -15$, $\Delta AIC\simeq -13$) according to AIC and BIC model selection criteria.

    ↳ astro-ph.COgr-qchep-phUniverse(2022)·52 citations
11. 11*

    Kepler problem and chiral effective dynamics

    Katarzyna Bolonek-Lason · Joanna Gonera · Piotr Kosinski

    It is shown that by an appropriate canonical transformation Kepler dynamics can be put in the form which allows to exhibit the structure of the symmetry transformations related to the superintegrability. They appear to fit nicely into general scheme of nonlinear realizations. In new coordiantes the Kepler dynamics results from dimensional reduction of that describing low energy mesons with spontaneously broken chiral symmetry.

    ↳ math-phhep-phhep-thmath.MP+1PRE(2022)·0 citations
12. 12*

    Kinematic and vertex fitting package for the CMD-3 experiment

    S.S. Gribanov🇷🇺 · A.S. Popov🇷🇺

    In this article, we discuss a new software package of kinematic and vertex fitting for the CMD-3 experiment at the VEPP-2000 electron-positron collider. The authors describe in detail the fitting algorithm, parametrization of four-momenta and trajectories of various particles and present the results of testing the fitting package using events of Monte Carlo simulation of various $e^{+}{e}^{-}$ annihilation processes. The authors also provide several examples of the fitting package validation using Gaussian simulation. Although the package discussed in this article is intended for the CMD-3 experiment, it can also be used in other experiments. The authors consider the described package as their first step towards a more universal and rigrous kinematic and vertex fitting package that can be used in future $e^{+}{e}^{-}$ experiments, such as the Super Charm-Tau factory.

    ↳ hep-exhep-phJINST·5 citations
13. 13*

    Probing neutrino interactions and dark radiation with gravitational waves

    Marilena Loverde🇺🇸 · Zachary J. Weiner🇺🇸

    After their generation, cosmological backgrounds of gravitational waves propagate nearly freely but for the expansion of the Universe and the anisotropic stress of free-streaming particles. Primordial signals -- both that from inflation and the infrared spectrum associated to subhorizon production mechanisms -- would carry clean information about the cosmological history of these effects. We study the modulation of the standard damping of gravitational waves by free-streaming radiation due to the decoupling (or recoupling) of interactions. We focus on nonstandard neutrino interactions in effect after the decoupling of weak interactions as well as more general scenarios in the early Universe involving other light relics. We develop semianalytic results in fully free-streaming scenarios to provide intuition for numerical results that incorporate interaction rates with a variety of temerpature dependencies. Finally, we compute the imprint of neutrino interactions on the $B$-mode polarization of the cosmic microwave background, and we comment on other means to infer the presence of such effects at higher frequencies.

    ↳ astro-ph.COgr-qchep-phJCAP(2023)·26 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.