Search for Parity Violation in 93Nb Neutron Resonances

E I. Sharapov, Joint Institute for Nuclear Research
J D. Bowman, Los Alamos National Laboratory
Bret E. Crawford, Gettysburg College
P P J. Delheij, TRIUMF
C M. Frankle, Los Alamos National Laboratory
K Fukuda, Meiji College of Oriental Medicine
M IInuma, Kyoto University
J N. Knudsen, Los Alamos National Laboratory
J Lokitz, North Carolina State University
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
H M. Shimizu, National Laboratory for High Energy Physics
Sharon L. Stephenson, Gettysburg College
Y-F Yen, Los Alamos National Laboratory
V W. Yuan, Los Alamos National Laboratory

Copyright held by American Physical Society. First published as EI Sharapox et al, Search for Parity Violation in 93Nb Neutron Resonances, Physical Review C, 59:2, 1131-1135, doi: 10.1103/PhysRevC.59.1131.

Abstract

A new search has been performed for parity violation in the compound nuclear states of ⁹⁴Nb by measuring the helicity dependence of the neutron total cross section. Transmission measurements on a thick niobium target were performed by the time-of-flight method at the Manuel Lujan Neutron Scattering Center with a longitudinally polarized neutron beam in the energy range 32 to 1000 eV. A total of 18 p-wave resonances in ⁹³Nb were studied with none exhibiting a statistically significant parity-violating longitudinal asymmetry. An upper limit of 1.0×10^-7 eV (95% confidence level) was obtained for the weak spreading widthΓ_w in ⁹³Nb.