Quark Matter 2014 - XXIV International Conference on Ultrarelativistic Nucleus-Nucleus Collisions

19-24 May 2014
Europe/Zurich timezone

Properties of neutral pions in a hot and magnetized quark matter

20 May 2014, 16:30
2h

spectrum

Board: A-20
Poster QCD at High Temperature and/or Density

Speaker

Prof. Neda Sadooghi (Department of Physics, Sharif University of Technology, Tehran, Iran)

Description

The study of quark matter at extreme temperature and in the presence of very strong magnetic fields has attracted much attention over the past few years. There are evidences for the creation of very strong and short-living magnetic fields in the early stages of noncentral heavy ion collisions at RHIC and LHC. Depending on the collision energies and impact parameters, they are estimated to be of order $eB\sim 1.5 m_{\pi}^{2}$ at RHIC and $eB\sim 15 m_{\pi}^{2}$ at LHC. In this talk, we will focus on the effect of constant magnetic fields on the properties of neutral mesons in a hot and dense quark matter. In particular, we will explore the temperature (T) dependence of neutral pion masses as well as their refraction indices for various fixed magnetic fields (eB). Moreover, using the generalized PCAC relations for hot and magnetized pions, we will derive the low energy Goldberger-Treiman (GT) and Gell--Mann-Oakes-Renner (GOR) theorems for neutral pions at finite T and eB. To do this, we will mainly use the energy dispersion relation of neutral pions, including nontrivial form factors. It will be derived from the effective action of a two-flavor Nambu--Jona-Lasinio model in a derivative expansion up to second order. We will show that the refraction index of neutral pions exhibits certain anisotropy in the transverse and longitudinal directions with respect to the direction of the external magnetic field. Moreover, as it turns out, the transverse refraction indices are, in contrast to their longitudinal refraction indices, larger than unity. These results are consistent with generalized low energy GT and GOR theorems for neutral pions at finite T and eB.

Primary author

Prof. Neda Sadooghi (Department of Physics, Sharif University of Technology, Tehran, Iran)

Co-author

Dr Shima Fayazbakhsh (Institute for research in fundamental sciences, School of particles and accelerators, Tehran, Iran)

 Poster