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ID 19318
file
creator
Sharapov, E. I.
Bowman, J. D.
Crawford, B. E.
Delheij, P. P. J.
Frankle, C. M.
Knudson, J. N.
Lowie, L. Y.
Lynch, J. E.
Masaike, Akira
Matsuda, Yasuyuki
Mitchell, G. E.
Penttilä, S. I.
Postma, H.
Roberson, N. R.
Seestrom, S. J.
Stephenson, S. L.
Yen, Y.-F.
Yuan, V. W.
abstract
The analysis of parity nonconservation (PNC) measurements performed on 232Th by the TRIPLE Collaboration has been extended to include the neutron energy range of 250 to 1900 eV. Below 250 eV all ten statistically significant parity violations have the same sign. However, at higher energies PNC effects of both signs were observed in the transmission of longitudinally polarized neutrons through a thick thorium target. Although the limited experimental energy resolution precluded analysis in terms of the longitudinal asymmetry, parity violations were observed and the cross section differences for positive and negative neutron helicities were obtained. For comparison, a similar analysis was performed on the data below 250 eV, for which longitudinal asymmetries were obtained previously. For energies below 250 eV, the p-wave neutron strength functions for the J= 1/2 and J = 3/2 states were extracted: S11/2=(1.68±0.61) × 10-4 and S13/2=(0.75±0.18) × 10-4. The data provide constraints on the properties of local doorway states proposed to explain the PNC sign effect in thorium.
journal title
Physical Review C - Nuclear Physics
volume
Volume 62
issue
Issue 2
start page
025501-1
end page
025501-7
date of issued
2000-01-18
publisher
American Physical Society
issn
0556-2813
ncid
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
publisher
rights
Copyright (c) 2000 The American Physical Society.
relation url
department
Graduate School of Advanced Sciences of Matter