Fermion helicity flip by parity violating torsion

Abstract

The helicity flip of a spin-1/2 Dirac fermion interacting with a torsion- field endowed with a pseudo-tensorial extension is analysed. Taking the torsion to be represented by a Kalb-Ramond field, we show that there is a finite amplitude for helicity flip for massive fermions. The lowest order contribution is proportional to the pseudo-tensor term.Comment: 5 pages, Revtex, Two figures, Title changed in the modified version. Few discussions added.No change in the conclusion. Accepted for publication In Physics Letters