Mon·Aug 7, 2017Monday·August 7, 2017

1. 01*

   Structure of Right-Handed Neutrino Mass Matrix

   Yoshio Koide🇯🇵

   Recently, Nishiura and the author have proposed a unified quark-lepton mass matrix model under a family symmetry U(3)$\times$U(3)${}^{\prime }$. The model can give excellent parameter-fitting to the observed quark and neutrino data. The model has a reasonable basis as far as the quark sector, but the form of the right-handed neutrino mass matrix $M_R$ does not have a theoretical grand, that is, it was nothing but a phenomenological assumption. In this paper, it is pointed out that the form of $M_R$ is originated in structure of neutrino mass matrix for $({\nu }_i,N_{\alpha })$ where ${\nu }_i$ ($i=1,2,3$) and $N_{\alpha }$ ($\alpha =1,2,3$) are U(3)-family and U(3)${}^{\prime }$-family triplets, respectively.

   hep-phPRD(2017)·1 citation
2. 02*

   Elastic scattering of virtual photons via quark loop in Double-Logarithmic Approximation

   B.I. Ermolaev🇷🇺 · D.Yu. Ivanov🇷🇺 · S.I. Troyan🇷🇺

   We calculate the amplitude of elastic photon-photon scattering via a single quark loop in the Double-Logarithmic Approximation, presuming all external photons to be off-shell and unpolarized.. At the same time we account for the running coupling effects. We consider this process in the forward kinematics at arbitrary relations between t and the external photon virtualities. We obtain explicit expressions for the photon-photon scattering amplitudes in all double-logarithmic kinematic regions. Then we calculate the small-x asymptotics of the obtained amplitudes and compare them with the parent amplitudes, thereby fixing the applicability regions of the asymptorics, i.e. fixing the applicability region for the non-vacuum Reggeons. We find that these Reggeons should be used at x < 10^{-8} only.

   hep-phhep-exPRD(2018)·3 citations
3. 03*

   Majorana Neutrino as Bogoliubov Quasiparticle

   Kazuo Fujikawa🇯🇵 · Anca Tureanu🇫🇮

   We suggest that the Majorana neutrino should be regarded as a Bogoliubov quasiparticle that is consistently understood only by use of a relativistic analogue of the Bogoliubov transformation. The unitary charge conjugation condition $\mathcal{C}\psi {\mathcal{C}}^{†}=\psi$ is not maintained in the definition of a quantum Majorana fermion from a Weyl fermion. This is remedied by the Bogoliubov transformation accompanying a redefinition of the charge conjugation properties of vacuum, such that a C-noninvariant fermion number violating term (condensate) is converted to a Dirac mass. We also comment on the chiral symmetry of a Majorana fermion; a massless Majorana fermion is invariant under a global chiral transformation $\psi \to \exp [i\alpha {\gamma }_5]\psi$ and different Majorana fermions are distinguished by different chiral $U(1)$ charge assignments. The reversed process, namely, the definition of a Weyl fermion from a well-defined massless Majorana fermion is also briefly discussed.

   hep-phcond-mat.supr-conhep-thPLB(2017)·17 citations
4. 04*

   Probing sub-GeV mass SIMP dark matter with a low-threshold surface experiment

   Jonathan H. Davis🇬🇧

   Using data from the $\nu$-cleus detector, based on the surface of the Earth, we place constraints on dark matter in the form of Strongly Interacting Massive Particles (SIMPs) which interact with nucleons via nuclear-scale cross sections. For large SIMP-nucleon cross sections the sensitivity of traditional direct dark matter searches using underground experiments is limited by the energy loss experienced by SIMPs, due to scattering with the rock overburden and experimental shielding on their way to the detector apparatus. Hence a surface-based experiment is ideal for a SIMP search, despite the much larger background, resulting from the lack of shielding. We show using data from a recent surface run of a low-threshold cryogenic detector that values of the SIMP-nucleon cross section up to approximately $10^{-27}$ cm${}^2$ can be excluded for SIMPs with masses above 100 MeV.

   hep-phastro-ph.COPRL(2017)·56 citations
5. 05*

   Improving the Simulation of Quark and Gluon Jets with Herwig 7

   Daniel Reichelt🇩🇪 · Peter Richardson🇨🇭 · Andrzej Siodmok🇵🇱

   The properties of quark and gluon jets, and the differences between them, are increasingly important at the LHC. However, Monte Carlo event generators are normally tuned to data from $e^{+}{e}^{-}$ collisions which are primarily sensitive to quark-initiated jets. In order to improve the description of gluon jets we make improvements to the perturbative and the non-perturbative modelling of gluon jets and include data with gluon-initiated jets in the tuning for the first time. The resultant tunes significantly improve the description of gluon jets and are now the default in Herwig 7.1.

   hep-phhep-exEPJC(2017)·68 citations
6. 06*

   Diffractive quarkonium photoproduction in $pp$ and $pA$ collisions at the LHC: Predictions of the Resolved Pomeron model for the Run 2 energies

   V. P. Goncalves🇧🇷 · L. S. Martins🇧🇷 · B. D. Moreira🇧🇷

   The inclusive diffractive quarkonium photoproduction in $pp$ and $pA$ collisions is investigated considering the Resolved Pomeron Model to describe the diffractive interaction. We estimate the rapidity and transverse momentum distributions for the $J/\Psi$, $\Psi (2S)$ and ${\rm Y}$ photoproduction in hadronic collisions at the LHC and present our estimate for the total cross sections at the Run 2 energies. A comparison with the predictions associated to the exclusive production also is presented. Our results indicate that the inclusive diffractive production is a factor $\gtrsim 10$ smaller than the exclusive one in the kinematical range probed by the LHC.

   hep-phhep-exPRD(2017)·8 citations
7. 07*

   Gauge-independent Renormalization of the N2HDM

   Marcel Krause🇩🇪 · David Lopez-Val🇩🇪 · Margarete Muhlleitner🇩🇪 · Rui Santos🇵🇹

   The Next-to-Minimal 2-Higgs-Doublet Model (N2HDM) is an interesting benchmark model for a Higgs sector consisting of two complex doublet and one real singlet fields. Like the Next-to-Minimal Supersymmetric extension (NMSSM) it features light Higgs bosons that could have escaped discovery due to their singlet admixture. Thereby, the model allows for various different Higgs-to-Higgs decay modes. Contrary to the NMSSM, however, the model is not subject to supersymmetric relations restraining its allowed parameter space and its phenomenology. For the correct determination of the allowed parameter space, the correct interpretation of the LHC Higgs data and the possible distinction of beyond-the-Standard Model Higgs sectors higher order corrections to the Higgs boson observables are crucial. This requires not only their computation but also the development of a suitable renormalization scheme. In this paper we have worked out the renormalization of the complete N2HDM and provide a scheme for the gauge-independent renormalization of the mixing angles. We discuss the renormalization of the ${\mathbb{Z}}_2$ soft breaking parameter $m_{12}^2$ and the singlet vacuum expectation value $v_S$. Both enter the Higgs self-couplings relevant for Higgs-to-Higgs decays. We apply our renormalization scheme to different sample processes such as Higgs decays into $Z$ bosons and decays into a lighter Higgs pair. Our results show that the corrections may be sizeable and have to be taken into account for reliable predictions.

   hep-phJHEP(2017)·37 citations
8. 08*

   Virtual signatures of dark sectors in Higgs couplings

   Alexander Voigt🇩🇪 · Susanne Westhoff🇩🇪

   Where collider searches for resonant invisible particles loose steam, dark sectors might leave their trace as virtual effects in precision observables. Here we explore this option in the framework of Higgs portal models, where a sector of dark fermions interacts with the standard model through a strong renormalizable coupling to the Higgs boson. We show that precise measurements of Higgs-gauge and triple Higgs interactions can probe dark fermions up to the TeV scale through virtual corrections. Observation prospects at the LHC and future lepton colliders are discussed for the so-called singlet-doublet model of Majorana fermions, a generalization of the bino-higgsino scenario in supersymmetry. We advocate a two-fold search strategy for dark sectors through direct and indirect observables.

   hep-phhep-exJHEP(2017)·20 citations
9. 09*

   Observation of Coherent Elastic Neutrino-Nucleus Scattering

   D. Akimov🇷🇺 · J.B. Albert🇺🇸 · P. An🇺🇸 · C. Awe🇺🇸 · P.S. Barbeau🇺🇸 · B. Becker🇺🇸 · V. Belov🇷🇺 · A. Brown🇺🇸 · A. Bolozdynya🇷🇺 · B. Cabrera-Palmer🇺🇸 · M. Cervantes🇺🇸 · J.I. Collar🇺🇸 and 69 other authors

   The coherent elastic scattering of neutrinos off nuclei has eluded detection for four decades, even though its predicted cross-section is the largest by far of all low-energy neutrino couplings. This mode of interaction provides new opportunities to study neutrino properties, and leads to a miniaturization of detector size, with potential technological applications. We observe this process at a 6.7-sigma confidence level, using a low-background, 14.6-kg CsI[Na] scintillator exposed to the neutrino emissions from the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. Characteristic signatures in energy and time, predicted by the Standard Model for this process, are observed in high signal-to-background conditions. Improved constraints on non-standard neutrino interactions with quarks are derived from this initial dataset.

   ↳ nucl-exhep-exhep-phnucl-thScience(2017)·1008 citations
10. 10*

    Effective interactions of hyperons and mass-radius relation of neutron stars

    Yeunhwan Lim🇺🇸 · Chang-Hwan Lee🇰🇷 · Yongseok Oh🇰🇷

    We examine the role of hyperons in a neutron star based on the relativistic mean field approach. For nuclear matter below 1.5 times the normal nuclear density we constrain the model parameters by using the symmetric nuclear matter properties and theoretical investigations for neutron matter in the literature. We then extend the model to higher densities by including hyperons and isoscalar vector mesons that contain strangeness degree of freedom. We confirm that the $\varphi$ meson induces a $\Lambda$ repulsive force and hardens the equation of state. The hardening arising from the $\varphi$ meson compensates the softening from the existence of hyperons. The flavor SU(3) and spin-flavor SU(6) relations are examined as well. We found that the coupling constants fitted by neutron matter properties could yield high enough maximum mass of a neutron star and the obtained results satisfy both the mass and radius constraints. The onset of the hyperon direct Urca process in neutron stars is also investigated using our parametrization.

    ↳ nucl-thastro-ph.SRhep-phPRD(2018)·19 citations
11. 11*

    Correlations of Energy-Momentum Tensor via Gradient Flow in SU(3) Yang-Mills Theory at Finite Temperature

    Masakiyo Kitazawa🇯🇵 · Takumi Iritani🇯🇵 · Masayuki Asakawa🇯🇵 · Tetsuo Hatsuda🇯🇵

    Euclidean two-point correlators of the energy-momentum tensor (EMT) in SU(3) gauge theory on the lattice are studied on the basis of the Yang-Mills gradient flow. The entropy density and the specific heat obtained from the two-point correlators are shown to be in good agreement with those from the one-point functions of EMT. These results constitute a first step toward the first principle simulations of the transport coefficients with the gradient flow.

    ↳ hep-lathep-phPRD(2017)·37 citations
12. 12*

    Thermodynamically consistent formulation of quasiparticle viscous hydrodynamics

    Radoslaw Ryblewski🇵🇱

    A novel formulation of second-order relativistic viscous fluid dynamics based on the effective Boltzmann equation for quasi-particles with medium-dependent masses is briefly reviewed.~The evolution equations for the shear and bulk dissipative corrections, and the corresponding transport coefficients, are presented. Resulting approach allows for thermodynamically-consistent incorporation of lattice QCD equation of state in the fluid dynamical framework.

    ↳ nucl-thhep-phActa Phys.Polon.Supp.(2017)·7 citations
13. 13*

    The Electron-Ion Collider: Assessing the Energy Dependence of Key Measurements

    E.C. Aschenauer🇺🇸 · S. Fazio🇺🇸 · J.H. Lee🇺🇸 · H. Mäntysaari🇺🇸 · B.S. Page🇺🇸 · B. Schenke🇺🇸 · T. Ullrich🇺🇸 · R. Venugopalan🇺🇸 · P. Zurita🇺🇸

    We provide an assessment of the energy dependence of key measurements within the scope of the machine parameters for a U.S. based Electron-Ion Collider (EIC) outlined in the EIC White Paper. We first examine the importance of the physics underlying these measurements in the context of the outstanding questions in nuclear science. We then demonstrate, through detailed simulations of the measurements, that the likelihood of transformational scientific insights is greatly enhanced by making the energy range and reach of the EIC as large as practically feasible.

    ↳ nucl-exhep-exhep-phnucl-thRept.Prog.Phys.(2019)·208 citations
14. 14*

    Renormalizability of the Refined Gribov-Zwanziger action in the linear covariant gauges

    M. A. L. Capri🇧🇷 · D. Fiorentini🇧🇷 · A. D. Pereira🇧🇷 · S. P. Sorella🇧🇷

    The Refined Gribov-Zwanziger framework takes into account the existence of equivalent gauge field configurations in the gauge-fixing quantization procedure of Euclidean Yang-Mills theories. Recently, this setup was extended to the family of linear covariant gauges giving rise to a local and BRST-invariant action. In this paper, we give an algebraic proof of the renormalizability of the resulting action to all orders in perturbation theory.

    ↳ hep-thhep-lathep-phPRD(2017)·43 citations
15. 15*

    On flavor symmetries of phenomenologically viable string compactifications

    Saul Ramos-Sanchez🇲🇽

    Heterotic orbifolds can explain the origin of flavor symmetries and the flavor representations of matter fields in particle physics as a result of the geometric properties of the associated string states in the compact space. After a review of the method to obtain flavor symmetries in these models, we determine the most frequent non-Abelian flavor symmetries appearing in promising Abelian heterotic orbifolds. Interestingly, these symmetries correspond only to D_4, Delta(54) and products of these symmetries and Abelian factors. A large set of promising models exhibits purely Abelian flavor symmetries. We finally explore the phenomenological potential of a sample model endowed with Delta(54) assuming certain ad hoc flavon expectation values.

    ↳ hep-thhep-phJ.Phys.Conf.Ser.(2017)·6 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.