CALCULATIONS OF DIRAC-SPINOR AMPLITUDES BY MEANS OF COMPLEX LORENTZ-TRANSFORMATIONS AND TRACE CALCULUS

A method for expressing spinor amplitudes M = ū(p′σ ′)ΓMu(pσ) in a formal covariant way and calculating them by trace calculations is described. By means of complex Lorentz transformations, an expression for u(pσ)ū(p′σ′) in terms of Dirac γ matrices, four vectors, and the complex Lorentz transformation coefficients is obtained. M can then be written as a trace of γ matrices similar to the expression for Σpo1|M| 2. The method is easily extended to cases when higher spin spinors and matrices are involved. © 1980 American Institute of Physics.