Experimental limits on the strength of right-handed ($e{\nu }_e$) and ($\mu {\nu }_{\mu }$) current couplings are discussed in connection with a recent conjecture that parity nonconservation arises from spontaneous breaking of left-right symmetry.

• Received 8 July 1977

DOI:https://doi.org/10.1103/PhysRevD.16.2369