Key points are not available for this paper at this time.
Failure to detect parity-violating effects in atomic transitions by Oxford and Washington groups would appear to rule out the Weinberg-Salam SU (2) (1) model as well as any variation of it that respects natural conservation laws for charm and strangeness to order G₅ (called "natural") and obeys quark-lepton symmetry. In this paper, a simple left-right-symmetric model based on the SU (2) ₋SU (2) ₑ (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.
Mohapatra et al. (Tue,) studied this question.