Observation of parity nonconservation in the total cross section and in the cross section for the radiative capture of polarized thermal neutrons in /sup 79,81/Br

Parity (P) nonconservation effects have been measured in the total and radiative cross sections in /sup 79,81/Br: (sigma/sup +//sub tot/-sigma/sup -//sub tot/)/(sigma/sup +//sub tot/+sigma/sup -//sub tot/) = (9.8 +- 1.0) x 10/sup -6/sigma/sub tot/) = 15.5 b and (sigma/sup +//sub ..gamma../-sigma/sup -//sub ..gamma../)/(sigma/sup +//sub ..gamma../+sigma/sup -//sub ..gamma../) = (15.5 +- 1.5) x 10/sup -6/sigma/sub ..gamma../ = 9.8 b, where the +- correspond to opposite neutron helicities. It follows from the results that the P-odd effect in the total cross section is determined by radiative capture, within the experimental error.