Parity Violation in Neutron Resonances in 115In

Sharon L. Stephenson, Gettysburg College
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
L Y. Lowie, North Carolina State University
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
Y-F Yen, Los Alamos National Laboratory
V W. Yuan, Los Alamos National Laboratory
L Zanini, Institute for Reference Materials and Measurements

Copyright held by American Physical Society. First published as SL Stephenson et al, Parity Violation in Neutron Resonances in 115In, Physical Review C, 61, 045501, doi: 10.1103/PhysRevC.61.045501.


Parity nonconservation (PNC) was studied in p-wave resonances in indium by measuring the helicity dependence of the neutron total cross section in the neutron energy range 6.0–316 eV with the time-of-flight method at LANSCE. A total of 36 p-wave neutron resonances were studied in 115In, and statistically significant asymmetries were observed for nine cases. An analysis treating the PNC matrix elements as random variables yields a weak matrix element of M=(0.67-0.12+0.16) meV and a weak spreading width of Γw=(1.30-0.43+0.76)×10-7 eV.