1. Measurement of parity-nonconserving rotation of neutron spin in the 0.734-eV p-wave resonance of $^{139}La$
- Author
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Haseyama, T., Asahi, K., Bowman, J. D., Delheij, P. P. J., Funahashi, H., Ishimoto, S., Jones, G., Masaike, A., Masuda, Y., Matsuda, Y., Morimoto, K., Muto, S., Penttilä, S. I., Pomeroy, V. R., Sakai, K., Sharapov, E. I., Smith, D. A., and Yuan, V. W.
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Nuclear Experiment - Abstract
The parity nonconserving spin rotation of neutrons in the 0.734-eV p-wave resonance of $^{139}La$ was measured with the neutron transmission method. Two optically polarized $^3He$ cells were used before and behind a a 5-cm long $^{139}La$ target as a polarizer and an analyzer of neutron spin. The rotation angle was carefully measured by flipping the direction of $^3He$ polarization in the polarizer in sequence. The peak-to-peak value of the spin rotation was found to be $ (7.4 \pm 1.1) \times 10^{-3} $ rad/cm which was consistent with the previous experiments. But the result was statisticallly improved. The s-p mixing model gives the weak matrix element as $xW = (1.71 \pm 0.25)$ meV. The value agrees well with the one deduced from the parity-nonconserving longitudinal asymmetry in the same resonance.
- Published
- 2001
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