Parity Nonconservation in Neutron Resonances in 133Cs

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
T Haseyama, 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
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 Sharapov et al, Parity Nonconservation in Neutron Resonances in 133Cs, Physical Review C, 59:3, 1772–1779, doi: 10.1103/PhysRevC.59.1772.


Spatial parity nonconservation (PNC) has been studied in the compound-nuclear states of 134Cs by measuring the helicity dependence of the neutron total cross section. Transmission measurements on a thick 133Cs 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 from 5 to 400 eV. A total of 28 new p-wave resonances were found, their neutron widths determined, and the PNC longitudinal asymmetries of the resonance cross sections measured. The value obtained for the root-mean-square PNC element M=(0.06-0.02+0.25) meV in 133Cs is the smallest among all targets studied. This value corresponds to a weak spreading width Γw=(0.006-0.003+0.154)×10-7 eV.