Thu·Dec 27, 2018Thursday·December 27, 2018

1. 01*

   Spin Polarization and Chiral Condensation in 2+1 flavor Nambu-Jona-Lasinio model at finite temperature and baryon chemical potential

   Aman Abhishek🇮🇳 · Arpan Das🇮🇳 · Hiranmaya Mishra🇮🇳 · Ranjita K. Mohapatra🇮🇳

   We investigate the ferromagnetic (spin polarization) condensation in (2+1) flavor Nambu Jona-Lasinio(NJL) model with non-zero current quark masses at finite temperature and density which may be relevant in the context of neutron stars. The spin polarization condensation arises due to a tensor type interaction which may be generated due to non-perturbative effects in Quantum Chromodynamics(QCD). In this investigation we have shown the interplay between chiral condensate and spin polarization condensation for different values of tensor coupling. Spin polarization in the case of 2+1 flavor is different from two flavor case because of additional F${}_8$ condensate associated with ${\lambda }_8^f$ flavor generator. We find a non-zero value of the two spin condensates in the chirally restored phase. Beyond a certain temperature the spin polarization condensates vanish for rather large quark chemical potentials. The spin condensates affect the chiral phase transition, quark masses, and the quark dispersion relation. The spin polarization condensate appears only in the chiral restored phase for light quarks. For large enough tensor couplings, it is observed that the spin polarization condensate acts as a catalyst for chiral symmetry restoration. Thermodynamic behavior of $F_3$ and $F_8$ are found to be different and they affect the quark masses differently.

   hep-phnucl-thPRD(2019)·3 citations
2. 02*

   Two simple textures of the magic neutrino mass matrix

   Kanwaljeet S. Channey🇮🇳 · Sanjeev Kumar🇮🇳

   The Tri-Bimaximal (TBM) mixing predicts a vanishing ${\theta }_{13}$. This can be attributed to the inherited $\mu -\tau$ symmetry of TBM mixing. We break its $\mu -\tau$ symmetry by adding a complex magic matrix with one variable to TBM neutrino mass matrix with one vanishing eigenvalue. We present two such textures and study their phenomenological implications.

   hep-phJ.Phys.G(2019)·21 citations
3. 03*

   Gravity-Mediated SUSY Breaking, R Symmetry and Hyperbolic Kaehler Geometry

   C. Pallis🇬🇷

   A novel realization of the gravity-mediated SUSY breaking is presented taking into account a continuous global R symmetry. Consistently with it, we employ a linear superpotential for the hidden sector superfield and a Kaehler potential parameterizing the SU(1,1)/U(1) Kaehler manifold with constant curvature -1/2. The classical vacuum energy vanishes without unnatural fine tuning and non-vanishing soft SUSY-breaking parameters, of the order of the gravitino mass, arise. A solution to the mu problem of MSSM may be also achieved by conveniently applying the Giudice-Masiero mechanism. The potentially troublesome R axion may acquire acceptably large mass by explicitly breaking the R symmetry in the Kaehler potential through a quartic term which does not affect, though, the achievements above.

   hep-phhep-thPRD(2019)·16 citations
4. 04*

   Correlations and degeneracies among the NSI parameters with tunable beams at DUNE

   Mehedi Masud🇪🇸 · Samiran Roy🇮🇳 · Poonam Mehta🇮🇳

   The Deep Underground Neutrino Experiment (DUNE) is a leading experiment in neutrino physics which is presently under construction. DUNE aims to measure the yet unknown parameters in the three flavour oscillation scenario which includes discovery of leptonic CP violation, determination of the mass hierarchy and determination of the octant of ${\theta }_{23}$. Additionally, the ancillary goals of DUNE include probing the sub-dominant effects induced by new physics. A widely studied new physics scenario is that of nonstandard neutrino interactions (NSI) in propagation which impacts the oscillations of neutrinos. We consider some of the essential NSI parameters impacting the oscillation signals at DUNE and explore the space of NSI parameters as well as study their correlations among themselves and with the yet unknown CP violating phase, $\delta$ appearing in the standard paradigm. The experiment utilizes a wide band beam and provides us with a unique opportunity to utilize different beam tunes at DUNE. We demonstrate that combining information from different beam tunes (low energy, LE and medium energy, ME) available at DUNE impacts the ability to probe some of these parameters and leads to altering the allowed regions in two-dimensional space of parameters considered.

   hep-phhep-exPRD(2019)·43 citations
5. 05*

   Spectral function and dilepton rate from a strongly magnetised hot and dense medium in the light of mean field models

   Chowdhury Aminul Islam🇮🇳 · Aritra Bandyopadhyay🇧🇷 · Pradip K. Roy🇮🇳 · Sourav Sarkar🇮🇳

   We have calculated the electromagnetic spectral function (SF) vis-à-vis the dilepton rate (DR) by evaluating the one-loop photon polarisation tensor for a strongly magnetised hot and dense medium. The calculation is performed in the ambit of mean field models namely Nambu\textendash Jona-Lasinio (NJL) and its Polyakov loop extended version (PNJL) in the lowest Landau level approximation. These models allow for a dynamical generation of quark mass which, evidently, gets affected in the presence of a magnetised medium. We have shown that the strength of the SF gets boosted because of the presence of dynamical quarks in lieu of the current quarks. It increases as we increase the magnetic field for a given value of temperature in both NJL and PNJL models. This increment is further reflected in the DR which is enhanced as compared to the Born rate for certain values of invariant masses. We also discuss the impact of chemical potential on DR within the present scenario.

   hep-phPRD(2019)·22 citations
6. 06*

   How to identify gluonium states using QCD counting rules

   Felipe J. Llanes-Estrada (Univ. Complutense Madrid)🇪🇸 · Stanley J. Brodsky (Stanford Linear Accelerator Center)🇺🇸

   Verifying the existence of bound states of gluons and distinguishing them from conventional quark-antiquark, hybrid or tetraquark states has remained a key problem in QCD. We show that QCD counting rules for the power-law fall-off of production cross sections at high momentum transfer can be used to distinguish gluonium states from conventional hadrons. The valence two-gluon contribution to a 0^+ gluonium bound state has L=0 and thus twist (dimension minus spin of their minimum interpolating operators) tau=2. The competing twist assignments for scalar f_0 mesons have twist tau = 3 for the valence |q qbar > configuration or |qqbar g> in an s-wave, and tau >= 4 for |q qbar qbar q > tetraquarks, etc. Thus, the production cross section for mesons with quark-containing valence wavefunctions relative to glueball production should be suppressed by at least a power of momentum transfer. Distinguishing these processes is feasible in exclusive e^-e^+ --> phi f_0 reactions at 9 and 11 GeV center of mass energy at Belle-II. In the case of single-particle inclusive hadroproduction A B --> C X, the cross section for scalar gluonium production at high transverse momentum p_T and fixed x_T = 2 p_T/sqrt(s) will dominate meson or tetraquark production by at least two powers of p_T.

   hep-phPoS(2018)·2 citations
7. 07*

   Ultrahigh-energy cosmic-ray nuclei and neutrinos from engine-driven supernovae

   B. Theodore Zhang🇨🇳 · Kohta Murase🇯🇵

   Transrelativistic supernovae (SNe), which are likely driven by central engines via jets or winds, have been among candidate sources of ultrahigh-energy cosmic rays (UHECRs). We investigate acceleration and survival of UHECR nuclei in the external reverse shock scenario. With composition models used in Zhang et al. (2018), we calculate spectra of escaping cosmic rays and secondary neutrinos. If their local rate is $\sim 1$% of the core-collapse supernova rate, the observed UHECR spectrum and composition can be explained with the total cosmic-ray energy ${\mathcal{E}}_{\mathrm{cr}}\sim 10^{51}$ erg. The maximum energy of UHECR nuclei can reach $\sim 10^{20}-{10}^{21}\mathrm{eV}$. The diffuse flux of source neutrinos is predicted to be $\sim 10^{-11}-10^{-10}\mathrm{GeV}{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}{\mathrm{sr}}^{-1}$ in the 0.1-1 EeV range, satisfying nucleus-survival bounds. The associated cosmogenic neutrino flux is calculated, and shown to be comparable or even higher than the source neutrino flux. These ultrahigh-energy neutrinos can be detected by ultimate detectors such as the Giant Radio Askaryan Neutrino Detector and Probe Of Extreme Multi-Messenger Astrophysics.

   ↳ astro-ph.HEastro-ph.SRhep-phnucl-thPRD(2019)·44 citations
8. 08*

   Graviton spectrum in simplified Dark Matter models with graviton mediators in the de Sitter space

   Ion V. Vancea🇧🇷

   This is the second in a series of papers investigating the formulation of the simplified Dark Matter models with graviton mediators in cosmological backgrounds. We address here the crucial problem of the fundamental observable of interest, namely the graviton spectrum in a FRW cosmological background with an arbitrary Dark Matter background component. We calculate the correction to the free graviton two-point function up to the second order in the coupling constant between the Dark Matter and the graviton in the simplified Dark Matter model with graviton mediators approach in the de Sitter space. Our result is model independent in the sense that it does not depend on the particular form of the Dark Matter fields. Also, due to the universality of the interaction between the Dark Matter and the graviton, the result obtained here apply to the interaction between the baryonic matter and the gravitons. As an application, we discuss in detail the massive scalar Dark Matter model and calculate the first order correction to the two-point function due to two Dark Matter modes in the adiabatic regime.

   ↳ gr-qchep-phhep-thUniverse(2019)·1 citation
9. 09*

   Efficiency correction for cumulants of multiplicity distributions based on track-by-track efficiency

   Xiaofeng Luo🇨🇳 · Toshihiro Nonaka🇨🇳

   We propose a simplified procedure for the experimental application of the efficiency correction on higher order cumulants in heavy-ion collisions. By using the track-by-track efficiency, we can eliminate possible bias arising from the average efficiencies calculated within the arbitrary binning of the phase space. Furthermore, the corrected particle spectra is no longer necessary for the average efficiency estimation and the time cost for the calculation of bootstrap statistical error can be significantly reduced.

   ↳ physics.data-anhep-exhep-phnucl-exPRC(2019)·38 citations
10. 10*

    Surface brightness profile of the 3.5 keV line in the Milky Way halo

    A. Boyarsky🇳🇱 · D. Iakubovskyi🇺🇦 · O. Ruchayskiy🇩🇰 · D. Savchenko🇺🇦

    We report a detection of 3.5 keV line in the Milky Way in 5 regions offset from the Galactic Center by distances from 10' to 35 degrees. We build an angular profile of this line and compare it with profiles of several astrophysical lines detected in the same observations. We compare our results with other detections and bounds previously obtained using observations of the Milky Way.

    ↳ astro-ph.HEhep-ph44 citations
11. 11*

    Emergent Dark Universe and the Swampland Criteria

    Rong-Gen Cai🇨🇳 · Sunly Khimphun🇰🇭 · Bum-Hoon Lee🇰🇷 · Sichun Sun🇮🇹 · Gansukh Tumurtushaa🇰🇷 · Yun-Long Zhang🇯🇵

    We study a model of the emergent dark universe, which lives on the time-like hypersurface in a five-dimensional bulk spacetime. The holographic fluid on the hypersurface is assumed to play the role of the dark sector, mainly including the dark energy and apparent dark matter. Based on the modified Friedmann equations, we present a Markov-Chain-Monte-Carlo analysis with the observational data, including type Ia Supernova and the direct measurement of the Hubble constant. We obtain a good fitting result and the matter component turns out to be small enough, which matches well with our theoretical assumption that only the normal matter is required. After considering the fitting parameters, an effective potential of the model with a dynamical scalar field is reconstructed. The parameters in the swampland criteria are extracted, and they satisfy the criteria at the present epoch but are in tension with the criteria if the potential is extended to the future direction. The method to reconstruct the potential is helpful to study the swampland criteria of other models without an explicit scalar field.

    ↳ hep-thastro-ph.COgr-qchep-phPhys.Dark Univ.(2019)·40 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.