Gauge theories of weak interactions with left-right symmetry and the structure of neutral currents

Abstract

Failure to detect parity-violating effects in atomic transitions by Oxford and Washington groups would appear to rule out the Weinberg-Salam $\mathrm{SU}(2)\ensuremath{\bigotimes}\mathrm{U}(1)$ model as well as any variation of it that respects natural conservation laws for charm and strangeness to order $\ensuremath{\alpha}$ ${G}_{F}$ (called "natural") and obeys quark-lepton symmetry. In this paper, a simple left-right-symmetric model based on the ${\mathrm{SU}(2)}_{L}\ensuremath{\bigotimes}{\mathrm{SU}(2)}_{R}\ensuremath{\bigotimes}\mathrm{U}(1)$ group with four and six quark flavors is analyzed and found to accomodate the results of the atomic experiments as well as the other features of neutral-current phenomena.