Parity violation in neutron resonances in Ag-107,Ag-109

Parity nonconservation (PNC) was studied in p-wave resonances in Ag by meas uring the helicity dependence of the neutron total cross section. Transmiss ion measurements on natural Ag were performed in the energy range 32 to 422 eV with the time-of-flight method at the Manuel Lujan Neutron Scattering C enter at Los Alamos National Laboratory. A total of 15 p-wave neutron reson ances were studied in Ag-107 and nine p-wave resonances in Ag-109. Statisti cally significant asymmetries were observed for eight resonances in Ag-107 and for four resonances in Ag-109. An analysis treating the PNC matrix elem ents as random variables yields a weak spreading width of Gamma(w) =(2.67(- 1.21)(+2.65))X10(-7) eV for Ag-107 and Gamma(w)=(1.30(-0.74)(+2.49))X10(-7) eV for Ag-109. [S0556-2813(99)03102-7].