Measurement of the angular distribution of prompt gamma-rays emitted in the ¹¹⁷Sn(n, γ) reaction for a T-violation search

¹ Department of Physics, Kyushu University, 744 Motooka, Nishi, Fukuoka 819–0395, Japan
² Research Center for Advanced Particle Physics, Kyushu University, 744 Motooka, Nishi, Fukuoka 819–0395, Japan
³ Department of Physics, Nagoya University, Furucho, Chikusa, Nagoya, Aichi 464–8062, Japan
⁴ Kobayashi-Maskawa Institute, Nagoya University, Furucho, Chikusa, Nagoya, Aichi, 464–8062, Japan
⁵ Institute of Material Structure Science, High Energy Accelerator Organization (KEK), Oho 1–1, Tsukuba, Ibaraki 305–0801, Japan
⁶ J-PARC center, Japan Atomic Energy Agency, Tokai, Ibaraki 319–1184, Japan
⁷ Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, Japan

^a e-mail: j.koga@epp.phys.kyushu-u.ac.jp

Published online: 12 December 2019

Abstract

It is theoretically suggested that the violation of charge conjugation and parity symmetry (CP-violation) could be enhanced in several compound nuclear reactions. According to the CPT theorem the violation of time-reversal symmetry (T-violation) would be enhanced too. The experimental sensitivity to find a T-violating effect in neutron-induced compound nuclear reactions depends on the value of a spin factor κ(J), which is a parameter specific for each nuclide. It can be determined from the angular dependence of γ-ray emission in (n,γ) reactions induced near a p-wave resonance. In this paper, the measurement result and the analysis status of experiments using the target nucleus ¹¹⁷Sn are reported.