Mon·Nov 23, 2020Monday·November 23, 2020

1. 01*

   Reaching the Planck scale with muon lifetime measurements

   Iarley P. Lobo🇧🇷 · Christian Pfeifer🇩🇪

   Planck scale modified dispersion relations are one way how to capture the influence of quantum gravity on the propagation of fundamental point particles effectively. We derive the time dilation between an observer's or particle's proper time, given by a Finslerian length measure induced from a modified dispersion relation, and a reference laboratory time. To do so, the Finsler length measure for general first order perturbations of the general relativistic dispersion relation is constructed explicitly. From this we then derive the time dilation formula for the $\kappa$-Poincaré dispersion relation in several momentum space bases, as well as for modified dispersion relations considered in the context of string theory and loop quantum gravity. Most interestingly we find that the momentum Lorentz factor in the present and future colliders can, in principle, become large enough to constrain the Finsler realization of the $\kappa$-Poincaré dispersion relation in the bicrossproduct basis as well as a string theory inspired modified dispersion relation, at Planck scale sensitivity with the help of the muon's lifetime.

   hep-phgr-qchep-thPRD(2021)·39 citations
2. 02*

   The chirality-flow formalism for the standard model

   Joakim Alnefjord🇸🇪 · Andrew Lifson🇸🇪 · Christian Reuschle🇸🇪 · Malin Sjodahl🇸🇪

   In a recent paper we introduced the chirality-flow formalism, a method for simple and transparent calculations of Feynman diagrams based on the left- and right-chiral $\mathrm{sl}(2,\mathbb{C})$ nature of spacetime. While our previous work focused on massless QED and QCD at tree-level, we here extend the chirality-flow formalism to the full (tree-level) Standard Model, including massive particles and electroweak interactions -- for which the $W$-interaction simplifies elegantly due to its chiral nature. We illustrate how values of Feynman diagrams can be immediately written down with some representative examples.

   hep-phhep-thEPJC(2021)·11 citations
3. 03*

   Testing momentum dependence of the nonperturbative hadron structure in a global QCD analysis

   A. Courtoy🇲🇽 · Pavel M. Nadolsky🇺🇸

   We discuss strategies for comparisons of nonperturbative QCD predictions for parton distribution functions (PDFs) with high-energy experiments in the region of large partonic momentum fractions $x$. Analytic functional forms for PDFs cannot be uniquely determined solely based on discrete experimental measurements because of a mathematical property of mimicry of PDF parametrizations that we prove using a representation based on Bézier curves. Predictions of nonperturbative QCD approaches for the $x$ dependence of PDFs instead should be cast in a form that enables decisive comparisons against experimental measurements. Predictions for effective power laws of $(1-x)$ dependence of PDFs may play this role. Expectations for PDFs in a proton based on quark counting rules are compared against the effective power laws of $(1-x)$ dependence satisfied by CT18 next-to-next-to-leading order parton distributions. We comment on implications for studies of PDFs in a pion, in particular on the comparison of nonperturbative approaches with phenomenological PDFs.

   hep-phPRD(2021)·40 citations
4. 04*

   Novel approach for the study of coherent elastic neutrino-nucleus scattering

   A. Galindo-Uribarri🇺🇸 · O. G. Miranda🇲🇽 · G. Sanchez Garcia🇲🇽

   We propose the use of isotopically highly enriched detectors for the precise study of coherent-elastic neutrino-nucleus scattering (CEvNS). CEvNS has been measured for the first time in CsI and recently confirmed with a liquid argon detector. It is expected that several new experimental setups will measure this process with increasing accuracy. Taking Ge detectors as a working example, we demonstrate that a combination of different isotopes is an excellent option to do precision neutrino physics with CEvNS, test Standard Model predictions, and probe new physics scenarios. Experiments based on this new idea can make simultaneous differential CEvNS measurements with detectors of different isotopic composition. Particular combination of observables could be used to cancel systematic errors. While many applications are possible, we illustrate the idea with three examples: testing the dominant quadratic dependence on the number of neutrons, $N$, that is predicted by the theoretical models; constraining the average neutron root mean square (rms) radius; and testing the weak mixing angle and the sensitivity to new physics. In all three cases we find that the extra sensitivity provided by this method will potentially allow high-precision robust measurements with CEvNS and particularly, will resolve the characteristic degeneracies appearing in new physics scenarios.

   hep-phPRD(2022)·16 citations
5. 05*

   Prediction of neutron electromagnetic form factors behaviors just by the proton electromagnetic form factors data

   Anna Z. Dubničková🇸🇰 · Stanislav Dubnička🇸🇰

   It is demonstrated how the neutron electromagnetic form factors behaviors in the whole region of their definition can be predicted theoretically just by using the proton form factors data to be described by the advanced proton electromagnetic structure Unitary and Analytic model.

   hep-phEPJA(2021)·3 citations
6. 06*

   Primordial monopolium as dark matter

   Vicente Vento🇪🇸

   The existence of monopoles is a characteristic signature of Kaluza-Klein multidimensional theories. The topology of these solutions is extremely interesting. The existence of a dipole solution, which we have associated to a monople-anti-monopole bound state, is the leitmotiv of this investigation. The dipole in its lowest energy state, which we here call also monopolium, is electromagnetically inert in free space interacting only gravitationally. Monopolium when interacting with time dependent magnetic fields acquires a time dependent induced magnetic moment and radiates. We have analyzed the most favorable astrophysical scenario for radiative monopolium and found that the amount of radiation is so small that is not detectable by conventional equipments. These findings suggest that Kaluza-Klein monopolium, if existent, would be a candidate for a primordial dark matter constituent.

   hep-phgr-qcEPJC(2021)·17 citations
7. 07*

   Investigating the transverse momentum dependent gluon Sivers function in quarkonium production at $pp$ colliders

   U. D'Alesio🇮🇹 · F. Murgia🇮🇹 · C. Pisano🇮🇹

   In this contribution, we will present a short overview of the transverse momentum dependent (TMD) approach as a tool for studying the 3-dimensional structure of hadrons in high-energy (un)polarized hadron collisions. We will then summarize the present status of a running research programme that aims at constraining the poorly known transverse momentum dependent gluon Sivers function, through the study of single spin asymmetries in quarkonium (mainly $J/\psi$), pion, and $D$-meson production in polarized proton-proton collisions at RHIC. Finally, we will shortly discuss perspectives for this field of research, emphasizing in particular its role in the physics programme of LHC in the fixed-target setup and NICA.

   hep-phnucl-thFew Body Syst.(2021)·1 citation
8. 08*

   Supersymmetric $\nu$-Inflaton Dark Matter

   Mar Bastero-Gil🇪🇸 · António Torres Manso🇪🇸

   We present the supersymmetric extension of the unified model for inflation and Dark Matter studied in Ref. arXiv:1811.02302. The scenario is based on the incomplete decay of the inflaton field into right-handed (s)neutrino pairs. By imposing a discrete interchange symmetry on the inflaton and the right-handed (s)neutrinos, one can ensure the stability of the inflaton field at the global minimum today, while still allowing it to partially decay and reheat the Universe after inflation. Compatibility of inflationary predictions, BBN bounds and obtaining the right DM abundance for the inflaton Dark Matter candidate typically requires large values of its coupling to the neutrino sector, and we use supersymmetry to protect the inflaton from potentially dangerous large radiative corrections which may spoil the required flatness of its potential. In addition, the inflaton will decay now predominatly into sneutrinos during reheating, which in turn give rise both to the thermal bath made of Standard Model particles, and inflaton particles. We have performed a through analyses of the reheating process following the evolution of all the partners involved, identifying the different regimes in the parameter space for the final Dark Matter candidate. This as usual can be a WIMP-like inflaton particle or an oscillating condensate, but we find a novel regime for a FIMP-like candidate.

   hep-phastro-ph.COgr-qchep-thJCAP(2021)·3 citations
9. 09*

   Alternative Minimal U(1)${}_{\mathrm{B}-\mathrm{L}}$

   Kento Asai🇯🇵 · Kazunori Nakayama🇯🇵 · Shih-Yen Tseng🇯🇵

   We provide a minimal alternative gauged U(1)${}_{\mathrm{B}-\mathrm{L}}$ model in which three right-handed neutrinos with charges of (5,-4,-4) and only one B-L Higgs field with charge 1 are introduced. Consistent active neutrino masses and mixings can be obtained if the $Z_2$ symmetry on two of the right-handed neutrinos is introduced. It predicts two heavy degenerate right-handed neutrinos, which may realize resonant leptogenesis scenario, and one relatively light sterile neutrino, which is a good dark matter candidate.

   hep-phPLB(2021)·7 citations
10. 10*

    Lepton Anomalous Magnetic Moments in an $S_4$ Flavor-Symmetric Extra U(1) Model

    Yasuhiro Daikoku🇯🇵 · Hiroshi Okada🇰🇷

    We study supersymmetric extra U(1) model with $S_4$ flavor symmetry. The flavor symmetry not only stabilizes proton but also suppresses the flavor changing processes without raising the supersymmetry breaking scale. After the flavor symmetry is broken, the Yukawa hierarchy is realized by the Froggatt-Nielsen mechanism. The relevant Peccei-Quinn scale for axion dark matter: $\frac{f_a}{M_P}\sim 10^{-5}$ accounts for small up quark mass. The muon mass scale: $\frac{m_{\mu }}{M_W}\sim 10^{-3}$ is related to the $O(10^{-6})$ mass degeneracy of right-handed neutrinos, from which we can identify the relevant scale of right-handed neutrino mass for baryon asymmetry of the Universe as TeV. Due to the existence of the extra higgsinos, the discrepancies of the anomalous magnetic moments of the muon and the electron between the standard model predictions and the observations are explained by the chargino-sneutrino contributions simultaneously.

    hep-ph5 citations
11. 11*

    Testing CP Properties of Extra Higgs States at the HL-LHC

    Stefan Antusch🇨🇭 · Oliver Fischer🇬🇧 · A. Hammad🇨🇭 · Christiane Scherb🇩🇪

    Extra Higgs states appear in various scenarios beyond the current Standard Model of elementary particles. If discovered at the LHC or future colliders, the question will arise whether CP is violated or conserved in the extended scalar sector. An unambiguous probe of (indirect) CP violation would be the observation that one of the extra Higgs particles is an admixture of a CP-even and a CP-odd state. We discuss the possibility to discover scalar CP violation in this way at the high-luminosity (HL) phase of the LHC. We focus on the Two-Higgs Doublet Model of type I, where we investigate its currently allowed parameter region. Considering a benchmark point that is compatible with the current constraints but within reach of the HL-LHC, we study the prospects of determining the CP property of an extra neutral Higgs state $H$ via the angular distribution of final states in the decay $H\to \tau \bar{\tau }$. The analysis is performed at the reconstructed level, making use of a Boosted Decision Tree for efficient signal-background separation and a shape analysis for rejecting a purely CP-even or odd nature of $H$.

    hep-phJHEP(2021)·17 citations
12. 12*

    Affleck-Dine inflation in supergravity

    Masahiro Kawasaki🇯🇵 · Shusuke Ueda🇯🇵

    Affleck-Dine inflation is a recently proposed model in which a single complex scalar field, nonminimally coupled to gravity, drives inflation and simultaneously generates the baryon asymmetry of universe via Affleck-Dine mechanism. In this paper we investigate the supersymmetric implementation of Affleck-Dine inflation in the use of two chiral superfields with appropriate superpotential and Kähler potential. The scalar potential has a similar form to the potential of original Affleck-Dine inflation, and it gives successful inflation and baryogenesis. We also consider the isocurvature perturbation evolving after crossing the horizon, and find that it is ignorable and hence consistent with the observations.

    hep-phastro-ph.COJCAP(2021)·21 citations
13. 13*

    Study of strongly intense quantities and robust variances in multi-particle production at LHC energies

    S.Belokurova🇷🇺

    The strongly intense quantities and robust variances in processes of multi-particle production in pp and AA interactions at LHC energies was studied. The Monte Carlo and analytic modelling of these quantities in the framework of a quark-gluon string model were implies. The string fusion effects were also taken into account by implementing of a lattice (grid) in the impact parameter plane. Strongly intensive variable $\Sigma (n_F,n_B)$ was calculated for different energies for two values of the width of the observation rapidity windows as a function of the distance between the centres of this windows. Scaled variance ${\omega }_n$ and robust variance $R_n$ for different energies and for different width of the observation rapidity window was calculated by MC simulations.

    hep-phPhys.Part.Nucl.(2022)·5 citations
14. 14*

    Exotic ${\bar{D}}_s^{(\ast )}{D}^{(\ast )}$ molecular states and $sc\bar{q}\bar{c}$ tetraquark states with $J^P=0^{+},1^{+},2^{+}$

    Qi-Nan Wang🇨🇳 · Wei Chen🇨🇳 · Hua-Xing Chen🇨🇳

    We have calculated the mass spectra for the ${\bar{D}}_s^{(\ast )}{D}^{(\ast )}$ molecular states and $sc\bar{q}\bar{c}$ tetraquark states with $J^P=0^{+},1^{+},2^{+}$. The masses of the axial-vector ${\bar{D}}_s{D}^{\ast }$, ${\bar{D}}_s^{\ast }D$ molecular states and $1_{[sc]}\oplus 0_{[\bar{q}\bar{c}]}$, $0_{[sc]}\oplus 1_{[\bar{q}\bar{c}]}$ tetraquark states are predicted to be around 3.98 GeV, which are in good agreement with the mass of $Z_{cs}(3985{)}^{-}$ from BESIII \cite{besiii2020Zcs}. In both the molecular and diquark-antidiquark pictures, our results suggest that there may exist two almost degenerate states, as the strange partners of the $X(3872)$ and $Z_c(3900)$. We propose to carefully examine the $Z_{cs}(3985)$ in future experiments to verify this. One may also search for more hidden-charm four-quark states with strangeness not only in the open-charm ${\bar{D}}_s^{(\ast )}{D}^{(\ast )}$ channels, but also in the hidden-charm channels ${\eta }_{c}K/K^{\ast }$, $J/\psi K/K^{\ast }$.

    hep-phhep-exCPC(2021)·51 citations
15. 15*

    Gravitational Production of a Conformal Dark Sector

    Michele Redi🇮🇹 · Andrea Tesi🇮🇹 · Hannah Tillim🇬🇧

    Dark sectors with purely gravitational couplings to the Standard Model are unavoidably populated from the SM plasma by graviton exchange, and naturally provide DM candidates. We examine the production in the relativistic regime where the dark sector is approximately scale invariant, providing general analytical formulas that depend solely on the central charge of the dark sector. We then assess the relevance of interactions that can lead to a variety of phenomena including thermalisation, nonperturbative mass gaps, out-of-equilibrium phase transitions and cannibalism in the dark sector. As an illustrative example we consider the dark glueball scenario in this light and show it to be a viable DM candidate due to the suppression of gravitational production. We go on to extend these results to strongly coupled CFTs and their holographic duals at large-N with the dark dilaton as the DM candidate.

    hep-phastro-ph.COhep-thJHEP(2021)·59 citations
16. 16*

    Study of $B_s\to \varphi {\ell }^{+}{\ell }^{-}$ decays in the PQCD factorization approach with lattice QCD input

    Su-Ping Jin🇨🇳 · Zhen-Jun Xiao🇨🇳

    In this paper, we studied systematically the semileptonic decays $B_s\to \varphi l^{+}{l}^{-}$ with $l^{-}=(e^{-},{\mu }^{-},{\tau }^{-})$ by using the perturbative QCD (PQCD) and the "PQCD+Lattice" factorization approach, respectively. We first evaluated all relevant form factors $F_i(q^2)$ in the low $q^2$ region using the PQCD approach, and we also took the available lattice QCD results at the high-$q^2$ region as additional input to improve the extrapolation of $F_i(q^2)$ from the low-$q^2$ region to the endpoint $q_{max}^2$. We then calculated the branching ratios and many other physical observables: $A_{FB}^l$, $F_L^{\varphi }$, $S_{3,4,7}$, $A_{5,6,8,9}$ and the clean angular observables $P_{1,2,3}$ and $P_{4,5,6,8}^{\prime }$.From our studies, we find the following points: (a) the PQCD and "PQCD+Lattice" predictions of $\mathcal{B}(B_s\to \varphi {\mu }^{+}{\mu }^{-})$ are about $7\times 10^{-7}$, which agree well with the LHCb measured values and the QCD sum rule prediction within still large errors; (b) we defined and calculated the ratios of the branching ratios $R_{\varphi }^{e\mu }$ and $R_{\varphi }^{\mu \tau }$; (c) the PQCD and "PQCD+Lattice" predictions of the longitudinal polarization $F_L$, the CP averaged angular coefficients $S_{3,4,7}$ and the CP asymmetry angular coefficients $A_{5,6,8,9}$, agree with the LHCb measurements in all considered bins within the still large experimental errors; and (d) for those currently still unknown observables $R_{\varphi }^{e\mu },R_{\varphi }^{\mu \tau },A_{FB}^l,P_{1,2,3}$ and $P_{4,5,6,8}^{\prime }$, we suggest LHCb and Belle-II Collaboration to measure them in their experiments.

    hep-phhep-exAdv.High Energy Phys.(2021)·5 citations
17. 17*

    Superheavy dark matter in $R^2$-cosmology

    E.V. Arbuzova🇷🇺

    The conventional Friedmann cosmology is known to be in tension with the existence of stable particles having interaction strength typical for supersymmetry and heavier than several TeV. A possible way to save life of such particles may be a modification of the standard cosmological expansion law in such a way that the density of these heavy relics would be significantly reduced. We study particle creation in the Starobinsky inflationary model for different decay channels of the scalaron. It is shown that in the process of thermalization superheavy stable particles with the coupling strength typical for the GUT SUSY could be created with the density equal to the observed density of dark matter.

    hep-phastro-ph.COInt.J.Mod.Phys.D(2021)·3 citations
18. 18*

    The algebra of anomaly interplay

    Joe Davighi🇬🇧 · Nakarin Lohitsiri🇬🇧

    We give a general description of the interplay that can occur between local and global anomalies, in terms of (co)bordism. Mathematically, such an interplay is encoded in the non-canonical splitting of short exact sequences known to classify invertible field theories. We study various examples of the phenomenon in 2, 4, and 6 dimensions. We also describe how this understanding of anomaly interplay provides a rigorous bordism-based version of an old method for calculating global anomalies (starting from local anomalies in a related theory) due to Elitzur and Nair.

    ↳ hep-thhep-phSciPost Phys.(2021)·52 citations
19. 19*

    Latent heat and pressure gap at the first-order deconfining phase transition of SU(3) Yang-Mills theory using the small flow-time expansion method

    Mizuki Shirogane🇯🇵 · Shinji Ejiri🇯🇵 · Ryo Iwami🇯🇵 · Kazuyuki Kanaya🇯🇵 · Masakiyo Kitazawa🇯🇵 · Hiroshi Suzuki🇯🇵 · Yusuke Taniguchi🇯🇵 · Takashi Umeda🇯🇵

    We study latent heat and the pressure gap between the hot and cold phases at the first-order deconfining phase transition temperature of the SU(3) Yang-Mills theory. Performing simulations on lattices with various spatial volumes and lattice spacings, we calculate the gaps of the energy density and pressure using the small flow-time expansion (SFtX) method. We find that the latent heat $\Delta ϵ$ in the continuum limit is $\Delta ϵ/T^4=1.117\pm 0.040$ for the aspect ratio $N_s/N_t=8$ and $1.349\pm 0.038$ for $N_s/N_t=6$ at the transition temperature $T=T_c$. We also confirm that the pressure gap is consistent with zero, as expected from the dynamical balance of two phases at $T_c$. From hysteresis curves of the energy density near $T_c$, we show that the energy density in the (metastable) deconfined phase is sensitive to the spatial volume, while that in the confined phase is insensitive. Furthermore, we examine the effect of alternative procedures in the SFtX method - the order of the continuum and the vanishing flow-time extrapolations, and also the renormalization scale and higher-order corrections in the matching coefficients. We confirm that the final results are all very consistent with each other for these alternatives.

    ↳ hep-lathep-phPTEP(2021)·22 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.