Normal ground state of dense relativistic matter in a magnetic field

Jan, 2011
28 pages
Published in:
  • Phys.Rev.D 83 (2011) 085003
e-Print:
Report number:
  • UWO-TH-11-1

Citations per year

20102014201820222024051015
Abstract: (arXiv)
The properties of the ground state of relativistic matter in a magnetic field are examined within the framework of a Nambu-Jona-Lasinio model. The main emphasis of this study is the normal ground state, which is realized at sufficiently high temperatures and/or sufficiently large chemical potentials. In contrast to the vacuum state, which is characterized by the magnetic catalysis of chiral symmetry breaking, the normal state is accompanied by the dynamical generation of the chiral shift parameter Δ\Delta. In the chiral limit, the value of Δ\Delta determines a relative shift of the longitudinal momenta (along the direction of the magnetic field) in the dispersion relations of opposite chirality fermions. We argue that the chirality remains a good approximate quantum number even for massive fermions in the vicinity of the Fermi surface and, therefore, the chiral shift is expected to play an important role in many types of cold dense relativistic matter, relevant for applications in compact stars. The qualitative implications of the revealed structure of the normal ground state on the physics of protoneutron stars are discussed. A noticeable feature of the Δ\Delta parameter is that it is insensitive to temperature when Tμ0T \ll \mu_0, where μ0\mu_0 is the chemical potential, and {\it increases} with temperature for T>μ0T > \mu_0. The latter implies that the chiral shift parameter is also generated in the regime relevant for heavy ion collisions.
Note:
  • 28 pages, 6 figures; v2: title changed in journal
  • 21.65.Qr
  • 12.38.Mh
  • 12.39.Ki
  • ground state
  • magnetic field
  • Jona-Lasinio-Nambu model
  • matter: relativistic
  • potential: chemical
  • symmetry breaking: chiral
  • temperature