Parity and Fermions in Front-Form: An Unexpected Result

Abstract

We show that under the operation of parity the {\it front-form} $(1/2,0)$ and $(0,1/2)$ Weyl spinors (massive or massless) do not get interchanged. This has the important consequence that if a front-form theory containing $(1/2,0)\oplus (0,1/2)$ representation space has to be parity covariant then one must study the evolution of a physical system not only along $x^{+}$ but also along the $x^{-}$ direction. As a result of our analysis, we find an indication that there may be no halving of the degrees of freedom in the front form of field theories.

Comments: LAUR-93-4317-REV, 10 pages, Revtex Version 3.0 (Accepted for publication in Phys. Lett. B)