학술논문
High sensitivity of a future search for P-odd/T-odd interactions on the 0.75 eV $p$-wave resonance in $\vec{n}+^{139}\vec{\rm La}$ forward transmission determined using pulsed neutron beam
Document Type
Working Paper
Author
Nakabe, R.; Auton, C. J.; Endo, S.; Fujioka, H.; Gudkov, V.; Hirota, K.; Ide, I.; Ino, T.; Ishikado, M.; Kambara, W.; Kawamura, S.; Kimura, A.; Kitaguchi, M.; Kobayashi, R.; Okamura, T.; Oku, T.; Okudaira, T.; Okuizumi, M.; Munoz, J. G. Otero; Parker, J. D.; Sakai, K.; Shima, T.; Shimizu, H. M.; Shinohara, T.; Snow, W. M.; Takada, S.; Takahashi, R.; Takahashi, S.; Tsuchikawa, Y.; Yoshioka, T.
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Subject
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Abstract
Neutron transmission experiments can offer a new type of highly sensitive search for time-reversal invariance violating (TRIV) effects in nucleon-nucleon interactions via the same enhancement mechanism observed for large parity violating (PV) effects in neutron-induced compound nuclear processes. In these compound processes, the TRIV cross-section is given as the product of the PV cross-section, a spin-factor $\kappa$, and a ratio of TRIV and PV matrix elements. We determined $\kappa$ to be $0.59\pm0.05$ for $^{139}$La+$n$ using both $(n, \gamma)$ spectroscopy and ($\vec{n}+^{139}\vec{\rm La}$) transmission. This result quantifies for the first time the high sensitivity of the $^{139}$La 0.75~eV $p$-wave resonance in a future search for P-odd/T-odd interactions in ($\vec{n}+^{139}\vec{\rm La}$) forward transmission.