Parity Nonconservation in Neutron Resonances in 107,109Ag

L Y. Lowie, North Carolina State University
J D. Bowman, Los Alamos National Laboratory
J Corvi, Institute for Reference Materials and Measurements
Bret E. Crawford, Gettysburg College
P P J. Delheij, TRIUMF
C M. Frankle, Los Alamos National Laboratory
M IInuma, Kyoto University
J N. Knudsen, Los Alamos National Laboratory
A Masaike, Kyoto University
Y Masuda, National Laboratory of High Energy Physics
Y Matsuda, Kyoto University
G E. Mitchell, North Carolina State University
S I. Penttila, Los Alamos National Laboratory
H Postma, Delft University of Technology
N R. Roberson, Duke University
S J. Seestrom, Los Alamos National Laboratory
E I. Sharapov, Joint Institute for Nuclear Research
H M. Shimizu, National Laboratory for High Energy Physics
Sharon L. Stephenson, Gettysburg College

Copyright held by American Physical Society. First published as LY Lowie et al, Parity Nonconservation in Neutron Resonances in 107,109Ag, Physical Review C, 59:2, 1119–1130, doi: 10.1103/PhysRevC.59.1119.

Abstract

Parity nonconservation (PNC) was studied in p-wave resonances in Ag by measuring the helicity dependence of the neutron total cross section. Transmission 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 Center at Los Alamos National Laboratory. A total of 15 p-wave neutron resonances were studied in ¹⁰⁷Ag and ninep-wave resonances in ¹⁰⁹Ag. Statistically significant asymmetries were observed for eight resonances in ¹⁰⁷Ag and for four resonances in¹⁰⁹Ag. An analysis treating the PNC matrix elements as random variables yields a weak spreading width of Γ_w=(2.67_-1.21^+2.65)×10^-7 eV for¹⁰⁷Ag and Γ_w=(1.30_-0.74^+2.49)×10^-7 eV for ¹⁰⁹Ag.