Mon·Apr 20, 2020Monday·April 20, 2020

1. 01*

   Degenerate Fermion Dark Matter from a Broken $U(1{)}_{\mathrm{B}-\mathrm{L}}$ Gauge Symmetry

   Gongjun Choi🇨🇳 · Motoo Suzuki🇨🇳 · Tsutomu. T. Yanagida🇨🇳

   The extension of the Standard model by assuming $U(1{)}_{\mathrm{B}-\mathrm{L}}$ gauge symmetry is very well-motivated since it naturally explains the presence of heavy right-handed neutrinos required to account for the small active neutrino masses via the seesaw mechanism and thermal leptogenesis. Traditionally, we introduce three right handed neutrinos to cancel the $[U(1{)}_{\mathrm{B}-\mathrm{L}}{]}^3$ anomaly. However, it suffices to introduce two heavy right-handed neutrinos for these purposes and therefore we can replace one right-handed neutrino by new chiral fermions to cancel the $U(1{)}_{\mathrm{B}-\mathrm{L}}$ gauge anomaly. Then, one of the chiral fermions can naturally play a role of a dark matter candidate. In this paper, we demonstrate how this framework produces a dark matter candidate which can address the so-called "core-cusp problem". As one of the small scale problems that $\Lambda$CDM paradigm encounters, it may imply an important clue for a nature of dark matter. One of resolutions among many is hypothesizing that sub-keV fermion dark matter halos in dwarf spheroidal galaxies are in (quasi) degenerate configuration. We show how the degenerate sub-keV fermion dark matter candidate can be non-thermally originated in our model and thus can be consistent with Lyman-$\alpha$ forest observation. Thereby, the small neutrino mass, baryon asymmetry, and the sub-keV dark matter become consequences of the broken B-L gauge symmetry.

   hep-phastro-ph.COPRD(2020)·15 citations
2. 02*

   A Common Origin of Neutrino Masses and $R_{D^{(\ast )}}$, $R_{K^{(\ast )}}$ Anomalies

   Shaikh Saad🇺🇸 · Anil Thapa🇺🇸

   In this work, we present a solution to the persistent tensions in the decay observables $R_{D^{(\ast )}}$ and $R_{K^{(\ast )}}$ by introducing a $SU(2{)}_L$ doublet and a $SU(2{)}_L$ triplet scalar leptoquarks (LQs) that reside at the TeV energy scale. Neutrinos that remain massless in the Standard Model receive naturally small masses at one-loop level via the propagation of the same LQs inside the loop. Such a common origin of apparently disjoint phenomenological observations is appealing, and we perform a comprehensive analysis of this set-up. We identify the minimal Yukawa textures required to accommodate these flavor anomalies and to successfully incorporate neutrino oscillation data while being consistent with all experimental constraints. This scenario has the potential to be tested at the experiments by the future improved measurements in the lepton flavor violating processes. Furthermore, proper explanations of these flavor anomalies predict TeV scale LQs that are directly accessible at the LHC.

   hep-phPRD(2020)·63 citations
3. 03*

   Weak magnetic field corrections to light vector or axial mesons mixings and vector meson dominance

   Fábio L. Braghin🇧🇷

   Weak magnetic field induced corrections to effective coupling constants describing light vector mesons mixings and vector meson dominance (VMD) are derived. The magnetic field must be weak with respect to an effective quark mass $M^{\ast }$ such that: $e{B}_0/{M^{\ast }}^2<1$ or $e{B}_0/{M^{\ast }}^2<<1$.For that, a flavor SU(2) quark-quark interaction due to non perturbative one gluon exchange is considered. By means of methods usually applied to the Nambu Jona Lasinio (NJL) and Global Color Models (GCM), leading light vector/axial mesons couplings to a background electromagnetic field are derived. The corresponding effective coupling constants are resolved in the structureless mesons and longwavelength limits. Some of the resulting coupling constants are redefined such as to become magnetic field induced corrections to vector or axial mesons couplings. Due to the approximated chiral symmetry of the model, light axial mesons mixings induced by the magnetic field are also obtained. Some numerical estimates are presented for the coupling constants and for some of the corresponding momentum dependent vertices. The contributions of the induced VMD and vector mesons mixing couplings for the low momentum pion electromagnetic form factor and for the (off shell) charge symmetry violation potential at the constituent quark level are estimated. The relative overall weak magnetic field-induced anisotropic corrections are of the order of $(e{B}_0/{M^{\ast }}^2{)}^n$, where $n=2$ or $n=1$ respectively.

   hep-phnucl-thJ.Phys.G(2020)·8 citations
4. 04*

   Heavy Neutral Leptons from kaon decays in the SHiP experiment

   Dmitry Gorbunov🇷🇺 · Igor Krasnov🇷🇺 · Yury Kudenko🇷🇺 · Sergey Suvorov🇷🇺

   We calculate the signal rate of hypothetical heavy neutral leptons (HNL or sterile neutrinos) from kaon decays expected in the framework of the SHiP experiment. The kaons are produced in the hadronic shower initiated in the beam-dump mode by 400 GeV protons from CERN SPS. For a sufficiently light HNL (when the decays are kinematically allowed) we find kaon decays to be a noticeably richer source of HNL as compared to $D$-meson decays adopted in previous studies of the HNL phenomenology at SHiP. In particular, SHiP is capable of fully exploring the central part of the kinematically allowed region of the HNL mass and mixing with electron and muon neutrinos down to the lower cosmological bound. The latter is associated with HNL decays in the early Universe to energetic products rescattering off and thus destroying light nuclei produced at the primordial nucleosynthesis. A consistency of the HNL model with smaller mixing would require either a hierarchy -- much larger mixing of all the HNL with tau neutrino -- or non-standard cosmology and new ingredients in the HNL sector, closing the room for the minimal non-seesaw type I model with sterile neutrinos lighter than kaons.

   hep-phastro-ph.COhep-exPLB(2020)·54 citations
5. 05*

   Scalar 1-loop Feynman integrals as meromorphic functions in space-time dimension d, II: Special kinematics

   Khiem Hong Phan🇻🇳

   Based on the method developed in [K.~H.~Phan and T.~Riemann, Phys.\ Lett.\ B {\bf 791} (2019) 257], detailed analytic results for scalar one-loop two-, three-, four-point integrals in general $d$-dimension are presented in this paper. The calculations are considered all external kinematic configurations and internal mass assignments. Analytic formulas are expressed in terms of generalized hypergeometric series such as Gauss ${}_2{F}_1$, Appell $F_1$ and Lauricella $F_S$ functions.

   hep-phEPJC(2020)·2 citations
6. 06*

   Particle correlations from the initial state

   Tolga Altinoluk🇵🇱 · Néstor Armesto🇪🇸

   The observation in small size collision systems, $pp$ and $p$A, of strong correlations with long range in rapidity and a characteristic structure in azimuth, the ridge phenomenon, is one of the most interesting results obtained at the Large Hadron Collider. Earlier observations of these correlations in heavy ion collisions at the Relativistic Heavy Ion Collider are standardly attributed to collective flow due to strong final state interactions, described in the framework of viscous relativistic hydrodynamics. Even though data for small size systems are well described in this framework, the applicability of hydrodynamics is less well grounded and initial state based mechanisms have been suggested to explain the ridge. In this review, we discuss particle correlations from the initial state point of view, with focus on the most recent theoretical developments.

   hep-phEPJA(2020)·30 citations
7. 07*

   $L_{\mu }-L_{\tau }$ effects to quarks and leptons from flavor unification

   Paul H. Frampton🇮🇹 · Sin Kyu Kang🇰🇷 · Jihn E. Kim🇰🇷 · Soonkeon Nam🇰🇷

   In the family grand unification models (fGUTs), we propose that gauge U(1)'s beyond the minimal GUT gauge group are family gauge symmetries. For the symmetry $L_{\mu }-L_{\tau }$, i.e. $Q_2-Q_3$ in our case, to be useful for the LHC anomaly, we discuss an SU(9) fGUT and also present an example in Georgi's SU(11) fGUT.

   hep-phPRD(2020)·3 citations
8. 08*

   Hadron and lepton tensors in semileptonic decays including new physics

   N. Penalva🇪🇸 · E. Hernández🇪🇸 · J. Nieves🇪🇸

   We extend our general framework for semileptonic decay, originally introduced in N. Penalva et al. [Phys. Rev. D100, 113007 (2019)], with the addition of new physics (NP) tensor terms. In this way, all the NP effective Hamiltonians that are considered in lepton flavour universality violation (LFUV) studies have now been included. Besides, we now also give general expressions that allow for complex Wilson coefficients. The scheme developed is totally general and it can be applied to any charged current semileptonic decay, involving any quark flavors or initial and final hadron states. We show that all the hadronic input, including NP effects, can be parametrized in terms of 16 Lorentz scalar structure functions. In the second part of this work, we use this formalism to obtain the complete NP effects in the ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ semileptonic decay, where LFUV, if finally confirmed, is also expected to be seen. We stress the relevance of the center of mass (CM) $d^2\Gamma /(d\omega d\cos {\theta }_{\ell })$ and laboratory (LAB) $d^2\Gamma /(d\omega d{E}_{\ell })$ differential decay widths. While models with very different strengths in the NP terms give the same differential $d\Gamma /d\omega$ and total decay widths for this decay, they predict very different numerical results for some of the $\cos {\theta }_{\ell }$ and $E_{\ell }$ coefficient-functions that determine the above two distributions. Thus, the combined analysis of the CM $d^2\Gamma /(d\omega d\cos {\theta }_{\ell })$ and LAB $d^2\Gamma /(d\omega d{E}_{\ell })$ differential decay widths will help clarifying what kind of NP is a better candidate in order to explain LFUV.

   hep-phhep-exPRD(2020)·20 citations
9. 09*

   Probing New Physics with Long-Range Neutrino Interactions: An Effective Field Theory Approach

   Patrick D. Bolton🇬🇧 · Frank F. Deppisch🇬🇧 · Chandan Hati🇩🇪

   We investigate forces induced by the exchange of two light neutrinos between Standard Model (SM) fermions in the presence of effective operators parametrising physics beyond the SM. We first set up a general framework in which we derive the long-range potential mediated by weakly interacting neutrinos in the SM, retaining both spin-independent and spin-dependent terms. We then derive neutrino-mediated potentials when there are vector, scalar and tensor non-standard interactions present as well as an exotic neutrino magnetic moment. Examining the phenomenology of such long-range potentials in atomic scale laboratory experiments, we derive upper bounds on the Wilson coefficients of the effective operators and compare these to those from processes such as charged lepton flavour violation.

   hep-phJHEP(2020)·26 citations
10. 10*

    Measuring Changes in the Atmospheric Neutrino Rate Over Gigayear Timescales

    Johnathon R. Jordan🇺🇸 · Sebastian Baum🇸🇪 · Patrick Stengel🇸🇪 · Alfredo Ferrari🇨🇭 · Maria Cristina Morone🇮🇹 · Paola Sala🇮🇹 · Joshua Spitz🇺🇸

    Measuring the cosmic ray flux over timescales comparable to the age of the solar system, $\sim 4.5$Gyr, could provide a new window on the history of the Earth, the solar system, and even our galaxy. We present a technique to indirectly measure the rate of cosmic rays as a function of time using the imprints of atmospheric neutrinos in paleo-detectors, natural minerals which record damage tracks from nuclear recoils. Minerals commonly found on Earth are $\lesssim 1$Gyr old, providing the ability to look back across cosmic ray history on timescales of the same order as the age of the solar system. Given a collection of differently aged samples dated with reasonable accuracy, this technique is particularly well-suited to measuring historical changes in the cosmic ray flux at Earth and is broadly applicable in astrophysics and geophysics.

    hep-phastro-ph.GAastro-ph.HEastro-ph.IM+2PRL(2020)·29 citations
11. 11*

    Generic dijet soft functions at two-loop order: uncorrelated emissions

    Guido Bell🇩🇪 · Rudi Rahn🇳🇱 · Jim Talbert🇩🇪

    We extend our algorithm for automating the calculation of two-loop dijet soft functions to observables that do not obey the non-Abelian exponentiation theorem, i.e. to those that require an independent calculation of the uncorrelated-emission contribution. As the singularity structure of uncorrelated double emissions differs substantially from the one for correlated emissions, we introduce a novel phase-space parametrisation that isolates the corresponding divergences. The resulting integrals are implemented in SoftSERVE 1.0, which we release alongside of this work, and which we supplement by a regulator that is consistent with the rapidity renormalisation group framework. Using our automated setup, we confirm existing results for various jet-veto observables and provide a novel prediction for the soft-drop jet-grooming algorithm.

    hep-phJHEP(2020)·28 citations
12. 12*

    Constraints on the coupling with photons of heavy axion-like-particles from Globular Clusters

    Pierluca Carenza (Bari Univ. & INFN Bari)🇮🇹 · Oscar Straniero (INAF)🇮🇹 · Babette Döbrich (CERN)🇨🇭 · Maurizio Giannotti (Barry Univ.)🇺🇸 · Giuseppe Lucente (Bari Univ.)🇮🇹 · Alessandro Mirizzi (Bari Univ. & INFN Bari)🇮🇹

    We update the globular cluster bound on massive ($m_a$ up to a few 100 keV) axion-like particles (ALP) interacting with photons. The production of such particles in the stellar core is dominated by the Primakoff $\gamma +Ze\to Ze+a$ and by the photon coalescence process $\gamma +\gamma \to a$. The latter, which is predominant at high masses, was not included in previous estimations. Furthermore, we account for the possibility that axions decay inside the stellar core, a non-negligible effect at the masses and couplings we are considering here. Consequently, our result modifies considerably the previous constraint, especially for $m_a\gtrsim 50$ keV. The combined constraints from Globular Cluster stars, SN 1987A, and beam-dump experiments leave a small triangularly shaped region open in the parameter space around $m_a\sim 0.5-1$ MeV and $g_{a\gamma }\sim 10^{-5}$ GeV${}^{-1}$. This is informally known as the ALP "cosmological triangle" since it can be excluded only using standard cosmological arguments. As we shall mention, however, there are viable cosmological models that are compatible with axion-like particles with parameters in such region. We also discuss possibilities to explore the cosmological triangle experimentally in upcoming accelerator experiments.

    hep-phastro-ph.SRhep-exPLB(2020)·104 citations
13. 13*

    Reheating and Post-inflationary Production of Dark Matter

    Marcos A. G. Garcia🇪🇸 · Kunio Kaneta🇺🇸 · Yann Mambrini🇫🇷 · Keith A. Olive🇺🇸

    We perform a systematic analysis of dark matter production during post-inflationary reheating. Following the period of exponential expansion, the inflaton begins a period of damped oscillations as it decays. These oscillations and the evolution of temperature of the thermalized decay products depend on the shape of the inflaton potential $V(\Phi )$. We consider potentials of the form ${\Phi }^k$. Standard matter-dominated oscillations occur for $k=2$. In general, the production of dark matter may depend on either (or both) the maximum temperature after inflation, or the reheating temperature, where the latter is defined when the Universe becomes radiation dominated. We show that dark matter production is sensitive to the inflaton potential and depends heavily on the maximum temperature when $k>2$. We also consider the production of dark matter with masses larger than the reheating temperature.

    hep-phastro-ph.COPRD(2020)·202 citations
14. 14*

    New limits on the resonant absorption of solar axions obtained with a ${}^{169}$Tm-containing cryogenic detector

    A. H. Abdelhameed🇩🇪 · S. V. Bakhlanov🇷🇺 · P. Bauer🇩🇪 · A. Bento🇩🇪 · E. Bertoldo🇩🇪 · L. Canonica🇩🇪 · A. V. Derbin🇷🇺 · I. S. Drachnev🇷🇺 · N. Ferreiro Iachellini🇩🇪 · D. Fuchs🇩🇪 · D. Hauff🇩🇪 · M. Laubenstein🇮🇹 and 16 other authors

    A search for resonant absorption of solar axions by ${}^{169}$Tm nuclei was carried out. A newly developed approach involving low-background cryogenic bolometer based on Tm${}_3$Al${}_5$O${}_{12}$ crystal was used that allowed for significant improvement of sensitivity in comparison with previous ${}^{169}$Tm based experiments. The measurements performed with $8.18$ g crystal during $6.6$ days exposure yielded the following limits on axion couplings: $|g_{A\gamma }(g_{AN}^0+g_{AN}^3)\le 1.44\times 10^{-14}$ GeV${}^{-1}$ and $|g_{Ae}(g_{AN}^0+g_{AN}^3)\le 2.81\times 10^{-16}$.

    ↳ hep-exastro-ph.SRhep-phphysics.ins-detEPJC(2020)·15 citations
15. 15*

    Femtoscopic correlations and the ${\Lambda }_{c}N$ interaction

    J. Haidenbauer🇩🇪 · G. Krein🇧🇷 · T. C. Peixoto🇧🇷

    We study the prospects for deducing constraints on the interaction of charmed baryons with nucleons from measurements of two-particle momentum correlation functions for ${\Lambda }_{c}p$. The correlation functions are calculated for ${\Lambda }_{c}N$ and ${\Sigma }_{c}N$ interactions that have been extrapolated from lattice QCD simulations at unphysical masses of $m_{\pi }=410-570$ MeV to the physical point using chiral effective field theory as guideline. In addition, we consider phenomenological $Y_{c}N$ models from the literature to explore the sensitivity of the results to the properties of the interaction in detail. We find that a measurement of the ${\Lambda }_{c}p$ correlation functions could indeed allow one to discriminate between strongly attractive ${\Lambda }_{c}N$ forces, as predicted by some phenomenological models, and a weakly attractive interaction as suggested by the presently available lattice simulations.

    ↳ nucl-thhep-phEPJA(2020)·22 citations
16. 16*

    Estimating the values and variations of neutron star observables by dense nuclear matter properties

    Péter Pósfay🇭🇺 · Gergely Gábor Barnaföldi🇭🇺 · Antal Jakovác🇭🇺

    Recent NICER observation data on PSR J0030+0451 has recently added a unique mass-radius constraint on the properties of the superdense nuclear matter existing in the interior of compact stars. Such a macroscopic data restrict further the microscopical models, elementary interactions, and their parameters, however, with reasonable margin because of the masquarade problem. Here our goal is to identify the origin and quantify the magnitude of the theoretical uncertainties of the nuclear matter models. A detailed study on the effect of different interaction terms and the nuclear parameter values in the Lagrangian of the extended $\sigma$-$\omega$ model is presented here. The equation of state was inserted to the Tolman--Oppenheimer--Volkoff equation and observable parameters of the neutron star were calculated. We identified, that the optimal Landau effective mass is the most relevant physical parameter modifying the macroscopic observable values. Moreover, the compressibility and symmetry energy terms just generate one-one order of magnitude smaller effect to this, respectively. We calculated the linear relations between the maximal mass of a compact star and these microscopic nuclear parameter values within the physical relevant parameters range. Based on the mass observational data we estimated the magnitude of the radii of PSR J1614-2230, PSR J0348+0432, and PSR J0740+6620 including theoretical uncertainties arising from the models' interaction terms and their parameter values choices.

    ↳ astro-ph.HEhep-phnucl-th4 citations
17. 17*

    The local-filament pattern in the anomalous transparency of the Universe for energetic gamma rays

    Sergey Troitsky🇷🇺

    The propagation length of high-energy photons through the Universe is limited by $e^{+}{e}^{-}$ pair production on the extragalactic background radiation. Previous studies reported discrepancies between predicted and observed attenuation, suggesting explanations in terms of new physics. However, these effects are dominated by a limited number of observed sources, while many do not show any discrepancy. Here, we consider the distribution in the sky of these apparently anomalous objects, selected in two very different approaches: the study of unphysical hardenings at distance-dependent energies in deabsorbed spectra of TeV blazars, and the observation of ultra-high-energy air showers from the directions of BL Lac type objects. In both cases, directions to the anomalous sources follow the projected local distribution of galaxies: all the distant sources, contributing to the anomalies, are seen through the local filament. This matches the prediction of the proposed earlier explanation of the anomalies based on mixing of photons with axion-like particles in the filament's magnetic field. For ultra-high energies, this axion interpretation may be tested by the search of primary gamma rays.

    ↳ astro-ph.HEhep-phEPJC(2021)·7 citations
18. 18*

    $H_0$ Tension, Phantom Dark Energy and Cosmological Parameter Degeneracies

    G. Alestas🇬🇷 · L. Kazantzidis🇬🇷 · L. Perivolaropoulos🇬🇷

    Phantom dark energy can produce amplified cosmic acceleration at late times, thus increasing the value of $H_0$ favored by CMB data and releasing the tension with local measurements of $H_0$. We show that the best fit value of $H_0$ in the context of the CMB power spectrum is degenerate with a constant equation of state parameter $w$, in accordance with the approximate effective linear equation $H_0+30.93w-36.47=0$ ($H_0$ in $kmse{c}^{-1}Mp{c}^{-1}$). This equation is derived by assuming that both ${\Omega }_{0\mathrm{m}}{h}^2$ and $d_A={\int }_0^{z_{rec}}\frac{dz}{H(z)}$ remain constant (for invariant CMB spectrum) and equal to their best fit Planck/$\Lambda$CDM values as $H_0$, ${\Omega }_{0\mathrm{m}}$ and $w$ vary. For $w=-1$, this linear degeneracy equation leads to the best fit $H_0=67.4kmse{c}^{-1}Mp{c}^{-1}$ as expected. For $w=-1.22$ the corresponding predicted CMB best fit Hubble constant is $H_0=74kmse{c}^{-1}Mp{c}^{-1}$ which is identical with the value obtained by local distance ladder measurements while the best fit matter density parameter is predicted to decrease since ${\Omega }_{0\mathrm{m}}{h}^2$ is fixed. We verify the above $H_0-w$ degeneracy equation by fitting a $w$CDM model with fixed values of $w$ to the Planck TT spectrum showing also that the quality of fit (${\chi }^2$) is similar to that of $\Lambda$CDM. However, when including SnIa, BAO or growth data the quality of fit becomes worse than $\Lambda$CDM when $w<-1$. Finally, we generalize the $H_0-w(z)$ degeneracy equation for $w(z)=w_0+w_{1}z/(1+z)$ and identify analytically the full $w_0-w_1$ parameter region that leads to a best fit $H_0=74kmse{c}^{-1}Mp{c}^{-1}$ in the context of the Planck CMB spectrum. This exploitation of $H_0-w(z)$ degeneracy can lead to immediate identification of all parameter values of a given $w(z)$ parametrization that can potentially resolve the $H_0$ tension.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2020)·200 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.