Measurement of the angular distribution of γ-rays emitted from the compound state after neutron capture by ⁸¹Br for a search of T-violation

¹ Department of Physics, Nagoya University, Furocho, Chikusa, Nagoya, Aichi, 464–8601, Japan
² Kobayashi-Maskawa Institute, Nagoya University, Furocho, Chikusa, Nagoya, Aichi, 464–8601, Japan
³ Research Center of Advanced Particle Physics, Kyushu University, 744 Motooka, Nishi, Fukuoka, Fukuoka 819–0395, Japan
⁴ Department of Physics, Kyushu University, 744 Motooka, Nishi, Fukuoka, Fukuoka 819–0395, Japan
⁵ J-PARC center, Japan Atomic Energy Agency, Tokai, Ibaraki 319–1184, Japan
⁶ Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319–1184, Japan
⁷ Institute of Material Structure Science, High Energy Accelerator Organization (KEK), Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan

^a e-mail: endo@phi.phys.nagoya-u.ac.jp

Published online: 12 December 2019

Abstract

It is known that parity violation can be enhanced in compound nuclei due to mixing of s- and p-waves, and it is suggested that time reversal invariance (T) violation is enhanced by the same mechanism. We are planing a T-violation search using compound nuclei produced in neutron capture reactions. Although ⁸¹Br is one of the candidate target nuclei, its sensitivity to T-violation has not yet been determined. For an estimate of the latter, a measurement of the angular distribution of γ-rays emitted in the ⁸¹Br(n,γ) reaction was carried out in November 2017, of which we report first results.