Thu·May 6, 2021Thursday·May 6, 2021

1. 01*

   Non-perturbative determination of collisional broadening and medium induced radiation in QCD plasmas

   Guy D. Moore🇩🇪 · Soeren Schlichting🇩🇪 · Niels Schlusser🇩🇪 · Ismail Soudi🇩🇪

   We supply recently obtained results from lattice EQCD with the correct UV limit to construct the collisional broadening kernel $C(b_{\perp })$ in a QCD plasma. We discuss the limiting behavior of $C(b_{\perp })$ at small and large impact parameters $b_{\perp }$, and illustrate how the results can be used to compute medium-induced radiation rates.

   hep-phhep-latJHEP(2021)·48 citations
2. 02*

   An extended 3-3-1 model with radiative linear seesaw mechanism

   A. E. Cárcamo Hernández🇨🇱 · Sergey Kovalenko🇨🇱 · Farinaldo S. Queiroz🇧🇷 · Yoxara S. Villamizar🇧🇷

   Motivated by the recent muon anomalous magnetic moment (g-2) measurement at FERMILAB and non-zero neutrino masses, we propose a model based on the $SU(3{)}_C\times SU(3{)}_L\times U(1{)}_X$ (3-3-1) gauge symmetry. The most popular 3-3-1 models in the literature require the presence of a scalar sextet to address neutrino masses. In our work, we show that we can successfully implement an one-loop linear seesaw mechanism with right-handed neutrinos, and vector-like fermions to nicely explain the active neutrino masses, and additionally reproduce the recent Muon g-2 result, in agreement with existing bounds.

   hep-phPLB(2022)·16 citations
3. 03*

   A closer look at observables from exclusive semileptonic $B\to (\pi ,\rho )\ell {\nu }_{\ell }$ decays

   Aritra Biswas🇮🇳 · Soumitra Nandi🇮🇳

   This article analyses the available inputs in $\text{btopilnu}$ and $\text{btorholnu}$ decays which include the measured values of differential rate in different $q^2$-bins (lepton invariant mass spectrum), lattice, and the newly available inputs on the relevant form-factors from the light-cone sum rules (LCSR) approach. We define different fit scenarios, and in each of these scenarios, we predict a few observables in the standard model (SM). For example, $R(M)=\frac{\mathcal{B}(B\to M{\ell }_i{\nu }_{{\ell }_i})}{\mathcal{B}(B\to M{\ell }_j{\nu }_{{\ell }_j})}$, $R_{{\ell }_j}^{{\ell }_i}(M)=\frac{\mathcal{B}(B\to {\ell }_i{\nu }_{{\ell }_i})}{\mathcal{B}(B\to M{\ell }_j{\nu }_{{\ell }_j})}$ with M = $\pi$ or $\rho$ and ${\ell }_{i,j}=e,\mu$ or $\tau$. We also discuss the new physics (NP) sensitivities of all these observables and obtain bounds on a few NP Wilson coefficients in $b\to u\tau {\nu }_{\tau }$ decays using the available data. We have noted that the data at present allows sizeable NP contributions in this mode. Also, we have predicted a few angular observables relevant to these decay modes.

   hep-phhep-exhep-latJHEP(2021)·11 citations
4. 04*

   First implications of Tibet AS${}_{\gamma }$ data for heavy dark matter

   Arman Esmaili🇧🇷 · Pasquale D. Serpico🇫🇷

   Extensive air shower detectors of gamma rays in the sub-PeV energy region provide a new and relatively unexplored window for dark matter searches. Here we derive some implications of the recently published Tibet AS${}_{\gamma }$ data for decaying dark matter candidates. The available spectral information is already useful in obtaining competitive constraints, surpassing existing limits above 10 PeV mass for hadronic or massive boson final states. This is particularly true if accounting for a benchmark astrophysical background of Galactic cosmic rays in the (0.1-1) PeV range. By relying on the arrival distribution of the photons, we show that significantly better sensitivity can be attained, comparable or better than IceCube also for most leptonic final states. Full data exploitation requires however further information disclosure.

   hep-phastro-ph.HEPRD(2021)·30 citations
5. 05*

   Electromagnetic properties of neutrinos from scattering on bound electrons in atom

   Junu Jeong🇰🇷 · Jihn E. Kim🇰🇷 · Sungwoo Youn🇰🇷

   We consider the effects of bound atomic electrons scattered by solar neutrinos due to the electromagnetic properties of neutrinos. This necessiate considering the recoil of atomic nucleus, which should be considered in the momentum conservation, but that effect to the energy conservation is negligible. This effect changes the kinematic behavior of the scattered electron compared to that scattered on free electrons. We apply this effect to the recent XENON1T data, but the bounds obtained from this is not very restrictive. We obtained the bounds: the (transition) magnetic moment $|f_{\alpha \beta }|\le 0.86\times 10^{-7}$ (times the electron Bohr magneton) and the charge radius $|\tilde{r}|<4.30\times 10^{-17}\mathrm{cm}$. For a non-vanishing millicharge ($\epsilon$), the allowed bound is shown in the ${\tilde{r}}^2-\epsilon$ plane.

   hep-phastro-ph.SRhep-exInt.J.Mod.Phys.A(2021)·7 citations
6. 06*

   Radiative neutrino masses: A window to new physics

   Ricardo Cepedello🇪🇸

   Neutrino oscillations constitute the first experimental confirmation of new physics, as they require a new piece that is absent in the Standard Model, non-zero neutrino masses. Questions such as how these masses are generated or why they are so small compared to other masses, are still under investigation. In this thesis, we study radiative neutrino mass models, a class of models where small neutrino masses are generated naturally, while the energy scale at which new physics appears is still low enough to be tested by current and future experiments, offering a falsifiable window to test beyond the Standard Model physics. In these models, neutrino masses are forbidden at the tree-level, but allowed at a certain order in loops. Consequently, we get masses suppressed by loop factors without requiring a large new physics scale and/or small couplings. In particular, we study the systematic classifications of the $d=7$ Majorana neutrino mass operator at one-loop order, the Weinberg operator at three-loop order and the $d=4$ Dirac neutrino mass models at the two-loop level. We then move to more specific models and mechanisms, analysing the connection between the generation of radiative neutrino masses and the stability of dark matter from a model-independent point of view, and examine a particular realisation of the type-I seesaw which relies on the radiative generation of Dirac Yukawa coupling. Finally, we analyse the phenomenology of some of the models discussed in the classifications, as well as a very particular case of neutrinoless double-$\beta$ decay where electrons are emitted with opposite chiralities along with a light scalar (Majoron).

   hep-ph2 citations
7. 07*

   Energy Spectrum of Thermalizing High Energy Decay Products in the Early Universe

   Manuel Drees🇩🇪 · Bardia Najjari🇩🇪

   We revisit the Boltzmann equation governing the spectrum of energetic particles originating from the decay of massive progenitors during the process of thermalization. We assume that these decays occur when the background temperature $T$ is much less than the mass $M$ of the progenitor. We pay special attention to the IR cutoff provided by the thermal bath, and include the suppression resulting from the interference of multiple scattering reactions (LPM effect). We solve the resulting integral equation numerically, and construct an accurate analytical fit of the solutions.

   hep-phastro-ph.COJCAP(2021)·36 citations
8. 08*

   Excited muon production at muon colliders via contact interaction

   M. Sahin (Usak University)🇹🇷 · A. Caliskan (Gumushane University)🇰🇷

   In recent years, with the enlightenment of some issues encountered at muon colliders, muon colliders have become more feasible for the high-energy physics community. For this reason, we studied single production of excited muon at muon colliders via contact interaction. Besides, we assumed that the excited muon is produced via contact interactions and decays to the photon and the muon through the gauge interaction. Then, signal and background analyses were performed at the muon anti-muon collider options with 6 TeV, 14 TeV, and 100 TeV center-of-mass energies for the excited muon. Attainable mass and compositeness scale limits were calculated for the excited muon at the muon anti-muon colliders. As a result of the calculations, it was concluded that the muon-antimuon colliders would be a perfect collider option for the excited muon investigations.

   hep-phhep-exJ.Phys.G(2023)·9 citations
9. 09*

   Impedance Matching to Axion Dark Matter: Considerations of the Photon-Electron Interaction

   Saptarshi Chaudhuri🇺🇸

   We introduce the concept of impedance matching to axion dark matter by posing the question of why axion detection is difficult, even though there is enough power in each square meter of incident dark-matter flux to energize a LED light bulb. By quantifying backreaction on the axion field, we show that a small axion-photon coupling does not by itself prevent an order-unity fraction of the dark matter from being absorbed through optimal impedance match. We further show, in contrast, that the electromagnetic charges and the self-impedance of their coupling to photons provide the principal constraint on power absorption integrated across a search band. Using the equations of axion electrodynamics, we demonstrate stringent limitations on absorbed power in linear, time-invariant, passive receivers. Our results yield fundamental constraints, arising from the photon-electron interaction, on improving integrated power absorption beyond the cavity haloscope technique. The analysis also has significant practical implications, showing apparent tension with the sensitivity projections for a number of planned axion searches. We additionally provide a basis for more accurate signal power calculations and calibration models, especially for receivers using multi-wavelength open configurations such as dish antennas and dielectric haloscopes.

   hep-phastro-ph.IMhep-exJCAP(2021)·8 citations
10. 10*

    Inflation, electroweak phase transition, and Higgs searches at the LHC in the two-Higgs-doublet model

    Lei Wang🇨🇳

    Combining the electroweak phase transition and the Higgs searches at the LHC, we study the Higgs inflation in the type-I and type-II two-Higgs-doublet models with non-minimally couplings to gravity. Considering relevant theoretical and experimental constraints, we find that the Higgs inflation imposes stringent constraints on the mass splitting between $A$, $H^{\pm }$ and $H$, and they tend to be nearly degenerate in mass with increasing of their masses. The direct searches for Higgs at the LHC can exclude many points achieving Higgs inflation in the region of $m_H(m_A)<$ 450 GeV in the type-I model, and impose a lower bound on $\tan \beta$ for the type-II model. The Higgs inflation disfavors the wrong sign Yukawa coupling region of type-II model. In the parameter space achieving the Higgs inflation, the type-I and type-II models can produce a first order electroweak phase transition, but $v_c/T_c$ is much smaller than 1.0.

    hep-phJHEP(2022)·11 citations
11. 11*

    $1/N_c$ approximation and universality of vector mesons

    M.K. Volkov🇷🇺 · A.A. Osipov🇷🇺 · A.A. Pivovarov🇷🇺 · K. Nurlan🇷🇺

    In this work, we argue that the observed differences in the value of the vector coupling constant extracted from the decays $\rho \to \pi \pi$ ($g_{\rho }=6.0$), $\rho \to l^{+}{l}^{-}$ ($g_{\rho }=5.0$) and $\omega \to l^{+}{l}^{-}$ ($g_{\rho }=5.7$), where $l=e,\mu$, are an indication of the important role played by the $1/N_c$ corrections in the description of these processes. We show that an emission of a photon by charged meson loops in the ${\rho }^0,\omega ,\varphi \to \gamma$ transitions is a key process that allows to describe above vector meson decays into two leptons with a single value $g_{\rho }=6.0$. Our result supports the idea of universality of neutral vector mesons and clarifies the role of accounting of $1/N_c$ corrections to its fulfilment.

    hep-phPRD(2021)·6 citations
12. 12*

    Impact of background effects on the inclusive $V_{cb}$ determination

    Thomas Mannel🇩🇪 · Muslem Rahimi🇩🇪 · K. Keri Vos🇳🇱

    The determination of the CKM element $V_{cb}$ from inclusive semileptonic $b\to c\ell \bar{\nu }$ decays has reached a high precision thanks to a combination of theoretical and experimental efforts. Aiming towards even higher precision, we discuss two processes that contaminate the inclusive $V_{cb}$ determination; the $b\to u$ background and the contribution of the tauonic mode: $b\to c(\tau \to \mu \nu \bar{\nu })\bar{\nu }$. Both of these contributions are dealt with at the experimental side, using Monte-Carlo methods and momentum cuts. However, these contributions can be calculated with high precision within the Heavy-Quark Expansion. In this note, we calculate the theoretical predictions for these two processes. The $b\to u$ results are compared with generator-level Monte-Carlo results used at Belle and Belle II. We have good agreement between theory and Monte-Carlo for lepton energy moments, but less for hadronic mass moments. Based on our results the uncertainties due to these backgrounds processes can basically be eliminated by properly including them into the analyses.

    hep-phJHEP(2021)·9 citations
13. 13*

    Heavy quark dynamics in a strongly magnetized quark-gluon plasma

    Aritra Bandyopadhyay🇨🇳 · Jinfeng Liao🇺🇸 · Hongxi Xing🇨🇳

    We present a calculation of the heavy quark momentum diffusion coefficients in a quark-gluon plasma under the presence of a strong external magnetic field, within the Lowest Landau Level (LLL) approximation. In particular, we apply the Hard Thermal Loop (HTL) technique for the resummed effective gluon propagator, generalized for a hot and magnetized medium. Using the derived effective HTL gluon propagator and the LLL quark propagator we analytically derive the full results for the longitudinal and transverse momentum diffusion coefficients as well as the energy losses for charm and bottom quarks beyond the static limit. We also show numerical results for these coefficients in two special cases where the heavy quark is moving either parallel or perpendicular to the external magnetic field.

    hep-phnucl-thPRD(2022)·24 citations
14. 14*

    Higgs boson decay to paired $B_c$: relativistic and one-loop corrections

    I. N. Belov🇷🇺 · A. V. Berezhnoy🇷🇺 · A. E. Dorokhov🇷🇺 · A. K. Likhoded🇷🇺 · A. P. Martynenko🇷🇺 · F. A. Martynenko🇷🇺

    The exclusive decays of the Higgs boson to $B_c{B}_c$ and $B_c^{\ast }{B}_c^{\ast }$ pairs are studied. The hard parts of the decay amplitudes are estimated within the perturbative Standard Model up to one-loop corrections. The soft fusion of heavy quarks to the quarkonium is described in framework of the relativistic quark model.

    hep-phNPA(2021)·15 citations
15. 15*

    Nucleon electroweak form factors using spin-improved holographic light-front wavefunctions

    Mohammad Ahmady🇨🇦 · Dipankar Chakrabarti🇮🇳 · Chandan Mondal🇨🇳 · Ruben Sandapen🇨🇦

    We construct spin-improved holographic light front wavefunctions for the nucleons (viewed as quark-diquark systems) and use them to successfully predict their electromagnetic Sachs form factors, their electromagnetic charge radii, as well as the axial form factor, charge and radius of the proton. The confinement scale is the universal mass scale of light-front holography, previously extracted from spectroscopic data for light hadrons. With the Dirac and Pauli form factors normalized using the quark counting rules and the measured anomalous magnetic moments respectively, the masses of the quark and diquark are the only remaining adjustable parameters. We fix them using the data set for the proton's Dirac-to-Pauli form factor ratio, and then predict all other data without any further adjustments of parameters. Agreement with data at low momentum-transfer is excellent. Our findings support the idea that light (pseudoscalar and vector) mesons and the nucleons share a nonperturbative universal holographic light-front wavefunction which is modified differently by their spin structures.

    hep-phNPA(2021)·13 citations
16. 16*

    Resummation of quantum radiation reaction and induced polarization

    Greger Torgrimsson🇩🇪

    In a previous paper we proposed a new method based on resummations for studying radiation reaction of an electron in a plane-wave electromagnetic field. In this paper we use this method to study the electron momentum expectation value for a circularly polarized monochromatic field with $a_0=1$, for which standard locally-constant-field methods cannot be used. We also find that radiation reaction has a significant effect on the induced polarization, as compared to the results without radiation reaction, i.e. the Sokolov-Ternov formula for a constant field, or the zero result for a circularly monochromatic field. We also study the Abraham-Lorentz-Dirac equation using Borel-Padé resummations.

    hep-phphysics.plasm-phPRD(2021)·22 citations
17. 17*

    Crystal responses to general dark matter-electron interactions

    Riccardo Catena🇸🇪 · Timon Emken🇸🇪 · Marek Matas🇨🇭 · Nicola A. Spaldin🇨🇭 · Einar Urdshals🇸🇪

    We develop a formalism to describe the scattering of dark matter (DM) particles by electrons bound in crystals for a general form of the underlying DM-electron interaction. Such a description is relevant for direct-detection experiments of DM particles lighter than a nucleon, which might be observed in operating DM experiments via electron excitations in semiconductor crystal detectors. Our formalism is based on an effective theory approach to general non-relativistic DM-electron interactions, including the anapole, and magnetic and electric dipole couplings, combined with crystal response functions defined in terms of electron wave function overlap integrals. Our main finding is that, for the usual simplification of the velocity integral, the rate of DM-induced electronic transitions in a semiconductor material depends on at most five independent crystal response functions, four of which were not known previously. We identify these crystal responses, and evaluate them using density functional theory for crystalline silicon and germanium, which are used in operating DM direct detection experiments. Our calculations allow us to set 90% confidence level limits on the strength of DM-electron interactions from data reported by the SENSEI and EDELWEISS experiments. The novel crystal response functions discovered in this work encode properties of crystalline solids that do not interact with conventional experimental probes, suggesting the use of the DM wind as a probe to reveal new kinds of hidden order in materials.

    hep-phastro-ph.COPRResearch(2021)·51 citations
18. 18*

    The Higgs mechanism from the effective theory of the non-minimal gravity action

    Suppanat Supanyo🇹🇭 · Monsit Tanasittikosol🇹🇭 · Sikarin Yoo-Kong🇹🇭 · Lunchakorn Tannukij🇹🇭

    The spontaneous symmetry breaking for the massless scalar field naturally arises from the framework of the effective theory (the non-minimal coupling of gravity to a scalar field). A magic key ingredient is to add the large vacuum energy density, contributing to the cosmological constant, to the Lagrangian density. By applying this modified spontaneous symmetry breaking with the gauge theory (called modified Higgs mechanism), the inflation physics and the electroweak phase transition can be generated from the same framework. However, this comes with the huge price-the large cosmological constant which is known as the dark energy problem. The possible solution of this issue is also discussed.

    hep-phhep-th0 citations
19. 19*

    Instantons with Quantum Core

    Viatcheslav Mukhanov🇩🇪 · Alexander Sorin🇷🇺

    We consider new instantons that appear as a result of accounting for quantum fluctuations. These fluctuations naturally regularize the O(4) singular solutions abandoned in Coleman's theory. In the previous works [3,4] we showed how new instantons modify the widely accepted picture of false vacuum decay in two particular examples of exactly solvable potentials. Here we generalize our consideration to arbitrary potentials and provide a general theory of these new instantons with quantum cores in which vacuum fluctuations dominate. We develop a method that allows us to determine the parameters of instantons for generic potentials not only in the thin-wall approximation but also in the cases where this approximation fails. Unlike the Coleman instantons, the instantons with quantum cores always exist in the cases where the vacuum must be unstable.

    ↳ hep-thgr-qchep-phmath-ph+2JCAP(2021)·7 citations
20. 20*

    Constraining $1+\mathcal{J}\to 2$ coupled-channel amplitudes in finite-volume

    Raul A. Briceno🇺🇸 · Jozef J. Dudek🇺🇸 · Luka Leskovec🇺🇸

    Whether one is interested in accessing the excited spectrum of hadrons or testing the standard model of particle physics, electroweak transition processes involving multi-hadron channels in the final state play an important role in a variety of experiments. Presently the primary theoretical tool with which one can study such reactions is lattice QCD, which is defined in a finite spacetime volume. In this work, we investigate the feasibility of implementing existing finite-volume formalism in realistic lattice QCD calculation of reactions in which a stable hadron can transition to one of several two-hadron channels under the action of an external current. We provide a conceptual description of the coupled-channel transition formalism, a practical roadmap for carrying out a calculation, and an illustration of the approach using synthetic data for two non-trivial resonant toy models. The results provide a proof-of-principle that such reactions can indeed be constrained using modern-day lattice QCD calculations, motivating explicit computation in the near future.

    ↳ hep-lathep-phPRD(2021)·45 citations
21. 21*

    $\mathcal{N}=4$ supersymmetric Yang-Mills thermodynamics to order ${\lambda }^2$

    Qianqian Du🇨🇳 · Michael Strickland🇺🇸 · Ubaid Tantary🇺🇸

    We calculate the resummed perturbative free energy of $\mathcal{N}=4$ supersymmetric Yang-Mills in four spacetime dimensions (${\text{SYM}}_{4,4}$) through second order in the 't Hooft coupling $\lambda$ at finite temperature and zero chemical potential. Our final result is ultraviolet finite and all infrared divergences generated at three-loop level are canceled by summing over ${\text{SYM}}_{4,4}$ ring diagrams. Non-analytic terms at $\mathcal{O}({\lambda }^{3/2})$ and $\mathcal{O}({\lambda }^2\log \lambda )$ are generated by dressing the $A_0$ and scalar propagators. The gauge-field Debye mass $m_D$ and the scalar thermal mass $M$ are determined from their corresponding finite-temperature self-energies. Based on this, we obtain the three-loop thermodynamic functions of ${\text{SYM}}_{4,4}$ to $\mathcal{O}({\lambda }^2)$. We compare our final result with prior results obtained in the weak- and strong-coupling limits and construct a generalized Padé approximant that interpolates between the weak-coupling result and the large-$N_c$ strong-coupling result. Our results suggest that the $\mathcal{O}({\lambda }^2)$ weak-coupling result for the scaled entropy density is a quantitatively reliable approximation to the scaled entropy density for $0\le \lambda \lesssim 2$.

    ↳ hep-thhep-phnucl-thJHEP(2021)·10 citations
22. 22*

    Acausality in Superfluid Dark Matter and MOND-like Theories

    Mark P. Hertzberg🇺🇸 · Jacob A. Litterer🇺🇸 · Neil Shah🇺🇸

    There has been much interest in novel models of dark matter that exhibit interesting behavior on galactic scales. A primary motivation is the observed Baryonic Tully-Fisher Relation in which the mass of galaxies increases as the quartic power of rotation speed. This scaling is not obviously accounted for by standard cold dark matter. This has prompted the development of dark matter models that exhibit some form of so-called MONDian phenomenology to account for this galactic scaling, while also recovering the success of cold dark matter on large scales. A beautiful example of this are the so-called superfluid dark matter models, in which a complex bosonic field undergoes spontaneous symmetry breaking on galactic scales, entering a superfluid phase with a 3/2 kinetic scaling in the low energy effective theory, that mediates a long-ranged MONDian force. In this work we examine the causality and locality properties of these and other related models. We show that the Lorentz invariant completions of the superfluid models exhibit high energy perturbations that violate global hyperbolicity of the equations of motion in the MOND regime and can be superluminal in other parts of phase space. We also examine a range of alternate models, finding that they also exhibit forms of non-locality.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2021)·9 citations
23. 23*

    Comment on "Massive electrodynamics and the magnetic monopoles"

    Michael Dunia🇺🇸 · Tim Evans🇺🇸 · Douglas Singleton🇺🇸

    In this paper we correct previous work on magnetic charge plus a photon mass. We show that contrary to previous claims this system has a very simple, closed form solution which is the Dirac string potential multiplied by a exponential decaying part. Interesting features of this solution are discussed, namely, (i) the Dirac string becomes a real feature of the solution, (ii) the breaking of gauge symmetry via the photon mass leads to a breaking of the rotational symmetry of the monopole's magnetic field, (iii) the Dirac quantization condition is potentially altered.

    ↳ hep-thhep-phquant-phPRD(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.