Dimensional reduction and catalysis of dynamical symmetry breaking by a magnetic field

Sep, 1995
48 pages
Published in:
  • Nucl.Phys.B 462 (1996) 249-290
e-Print:
Report number:
  • UCLA-95-TEP-26

Citations per year

199520032011201920250102030
Abstract:
It is shown that a constant magnetic field in 3+13+1 and 2+12+1 dimensions is a strong catalyst of dynamical chiral symmetry breaking, leading to the generation of a fermion dynamical mass even at the weakest attractive interaction between fermions. The essence of this effect is the dimensional reduction DD2D\to D-2 in the dynamics of fermion pairing in a magnetic field. The effect is illustrated in the Nambu--Jona--Lasinio (NJL) model and QED. In the NJL model in a magnetic field, the low--energy effective action and the spectrum of long--wavelenth collective excitations are derived. In QED, it is shown that the dynamical mass of fermions (energy gap in the fermion spectrum) is mdyn=CeBexp[π2(π2α) 1/2]m_{\rm dyn}=C\sqrt{|eB|}\exp[-\frac{\pi}{2}(\frac{\pi}{2\alpha})~{1/2}], where BB is the magnetic field, the constant CC is of order one and α=e 2/4π\alpha=e~2/4\pi is the renormalized coupling constant. Possible applications of this effect and its extension to inhomogeneous field configurations are discussed.
  • fermion
  • quantum electrodynamics
  • Jona-Lasinio-Nambu model
  • magnetic field
  • dimension: 4
  • dimensional reduction
  • dimension: 3
  • dimension: 2
  • dynamical symmetry breaking
  • numerical calculations