PaperPanorama
FAQ

Nuclear Theory·nucl-th

Monday·March 9, 2020

10 papers—3 primary·7 cross-listed

All10Primary3Cross-lists7
  1. 04

    Improved opacity expansion for medium-induced parton splitting

    Yacine Mehtar-Tani🇺🇸

    We revisit the calculation of the medium-induced gluon radiative spectrum and propose a novel expansion scheme that encompasses the two known analytic limits: i) the high frequency regime dominated by a single hard scattering that corresponds to the leading order in the standard opacity expansion, ii) the low frequency regime that is dominated by multiple soft scatterings. Our approach is based on expanding around the harmonic oscillator instead of vacuum in the leading logarithmic approximation. We compute the first two orders in this improved opacity expansion and show that they account for the aforementioned limits.

    ↳ hep-phnucl-thNPA(2021)·0 citations
  2. 05

    Lepton Pair Production Through Two Photon Process in Heavy Ion Collisions

    Spencer Klein🇺🇸 · Al Mueller🇺🇸 · Bo-Wen Xiao🇨🇳 · Feng Yuan🇺🇸

    This paper investigates the electromagnetic production of lepton pairs with low transverse momentum in relativistic heavy ion collisions. We estimate the initial photons' transverse momentum contributions by employing models where the average transverse momentum squared of the incoming photon can be calculated in the equivalent photon approximation. We further derive an all order QED resummation for the soft photon radiation, which gives an excellent description of the ATLAS data in ultra-peripheral collisions at the LHC. For peripheral and central collisions, additional -broadening effects from multiple interaction with the medium and the magnetic field contributions from the quark-gluon plasma are also discussed.

    ↳ hep-phhep-exnucl-exnucl-thPRD(2020)·90 citations
  3. 06

    The contributions of the vector-channel at finite isospin chemical potential with the self-consistent mean field approximation

    Zu-Qing Wu🇨🇳 · Chao-Shi🇨🇳 · Jia-Lun Ping🇨🇳 · Hong-Shi Zong🇨🇳

    The self-consistent mean field approximation of two-flavor NJL model, which introduces a free parameter ( reflects the weight of different interaction channels), is employed to investigate the contributions of the vector-channel at finite isospin chemical potential and zero baryon chemical potential and zero temperature . The calculations show that the consideration of the vector-channel contributions leads to lower value of pion condensate in superfluid phase, compared with the standard Lagrangian of NJL model (). In superfluid phase, we also obtain lower isospin number density, and the discrepancy is getting larger with the increase of isospin potential. Compared with the recent results from Lattice QCD, the isospin density and energy density we obtained with agree with the data of lattice well. In the phase diagram in the plane for , we can see that the difference of the critical temperatures of phase transition between the results with and is up to for a fixed isospin potential. All of these indicate that the vector channels play an important role in isospin medium.

    ↳ hep-phnucl-thPRD(2020)·9 citations
  4. 07

    Spatial and Momentum Imaging of the Pion and Kaon

    Chao Shi🇨🇳 · Kyle Bednar🇺🇸 · Ian C. Cloët🇺🇸 · Adam Freese🇺🇸

    We determine the leading Fock state light front wave functions (LFWFs) of the pion and kaon via light front projections of the covariant Bethe-Salpeter wave function. Using these LFWFs we study the multi-dimensional images of the valence quarks in the pion and kaon that are provided by their generalized parton distribution functions (GPDs) and transverse momentum dependent parton distribution functions (TMDs). Moments of the GPDs are taken to obtain the electromagnetic and gravitational form factors of the pion and kaon, and comparisons to available experimental and lattice data are made. Highlights from this study include predictions that the mean-squared impact parameter for the quarks in the pion and kaon are: fm, fm, and fm, and therefore the quark in the kaon is much closer to the center of transverse momentum than the quark. From the electromagnetic and gravitational form factors we find that the light-cone energy radii are about 60\% smaller than the light-cone charge radii for each quark sector in the pion and kaon. A quantitative measure of the importance of the leading Fock state is obtained via comparison with a full DSE calculation (containing an infinite tower of Fock states) for the pion form factor.

    ↳ hep-phnucl-thPRD(2020)·40 citations
  5. 08

    Radial Fulde-Ferrell-Larkin-Ovchinnikov state in a population-imbalanced Fermi gas

    Daisuke Inotani · Shigehiro Yasui · Takeshi Mizushima · Muneto Nitta

    The possibility of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state in a population imbalanced Fermi gas with a vortex is proposed. Employing the Bogoliubov-de-Gennes formalism we self-consistently determine the superfluid order parameter and the particle number density in the presence of a vortex. We find that as increasing population imbalance, the superfluid order parameter spatially oscillates around the vortex core in the radial direction, indicating that the FFLO state becomes stable. We find that the radial FFLO states cover a wide region of the phase diagram in the weak-coupling regime at in contrast to the conventional case without a vortex. We show that this inhomogeneous superfluidity can be detected as peak structures of the local polarization rate associated with the node structure of the superfluid order parameter. Since the vortex in the 3D Fermi gas with population imbalance has been already realized in experiments, our proposal is a promising candidate of the FFLO state in cold atom physics.

    ↳ cond-mat.quant-gascond-mat.supr-connucl-thPRA(2021)·5 citations
  6. 09

    Tsallis-thermometer: a QGP indicator for large and small collisional systems

    Gábor Bíró🇭🇺 · Gergely Gábor Barnaföldi🇭🇺 · Tamás Sándor Biró🇭🇺

    The transverse momentum distribution of identified hadrons from recent years are analyzed within the thermodynamically consistent formulation of non-extensive statistics. A wide range of center-of-mass energies and average event multiplicities are studied for various hadron species. We demonstrate that the average event multiplicity is a key variable in the study of high-energy collisions and a smooth transition in the description from small to large systems is possible. For this purpose the non-extensive statistical approach is more than appropriate. The validity of the non-extensive description is explored in multiple ways: such as the calculation of integrated yields per unit rapidity, the analysis of radial flow and the consistency check of the thermodynamical variables. The 'Tsallis-thermometer' is introduced as an indicator of quark-gluon plasma in small collisional systems.

    ↳ hep-phnucl-thJ.Phys.G(2020)·50 citations
  7. 10

    The Ground State Calculations for Some Nuclei by Mesonic Potential of Nucleon-Nucleon Interaction

    K.M.Hanna🇪🇬 · SH.M.Sewailem🇪🇬 · R.Hussien🇪🇬 · L. I. Abou-Salem🇪🇬 · Asmaa.G.Shalaby🇪🇬

    The interaction of Nucleon-Nucleon (NN) has certain physical characteristics, which indicated by nucleon, and meson degrees of freedom. The main purpose of this work is calculating the ground state energies of 21 Deutron and Alfa through the two-body system with the exchange of mesons (Pi, segma, omega) that mediated between two nucleons. This paper investigates NN interaction based on the quasi-relativistic decoupled Dirac equation and self-consistent Hartree-Fock formulation. We construct one-boson exchange potential (OBEP) model, where each nucleon is treated as a Dirac particle and acts as a source of pseudoscalar, scalar, and vector fields. The potential in the present work is analytically derived with two static functions of meson, the single particle energy dependent(SPED) and generalized Yukawa (GY) functions, the parameters used in meson functions are just published ones (mass, coupling constant,and cut o? parameters). The theoretical results are compared to other theoretical models and their corresponding experimental data, one can see that the SPED function gives more satisfied agreement than the GY function in case of the considered nuclei.

    ↳ hep-phnucl-thAdv.High Energy Phys.(2020)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE