Generalized two-point tree-level amplitude $jf\to j^{\prime }{f}^{\prime }$ in a magnetized medium (extended version)

Abstract

The tree-level two-point amplitudes for the transitions $jf\to j^{\prime }{f}^{\prime }$, where $f$ is a fermion and $j$ is a generalized current, in a constant uniform magnetic field of an arbitrary strength and in charged fermion plasma, for the $jf$ interaction vertices of the scalar, pseudoscalar, vector and axial-vector types have been investigated. The particular cases of a very strong magnetic field, and of the coherent scattering off the real fermions without change of their states (the "forward" scattering) have been analysed.

Comments: 37 pages, 1 eps figure, extended version of the paper submitted to Physical Review D; version 2: some misprints are corrected in Eqs. (29) - (72) and corresponding changes are made in Sec. 3 and 4; the gamma_5 matrix definition is specified, and general signs are changed correspondingly in the amplitudes PS, SP, AS, SA, PV, VP