Observation of spin-dependent charge symmetry breaking in interaction; -ray spectroscopy of He

相互作用におけるスピンに依存する荷電対称性の破れの観測; Heの線分光

山本 剛史*; 長谷川 勝一   ; 早川 修平; 細見 健二  ; Hwang, S.; 市川 裕大   ; 今井 憲一; 金原 慎二; 中田 祥之; 佐甲 博之   ; 佐藤 進  ; 杉村 仁志; 谷田 聖   ; J-PARC E13 Collaboration*; 他41名*

Yamamoto, T. O.*; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; Kimbara, Shinji; Nakada, Yoshiyuki; Sako, Hiroyuki; Sato, Susumu; Sugimura, Hitoshi; Tanida, Kiyoshi; J-PARC E13 Collaboration*; 41 of others*

The energy spacing between the spin-doublet bound state of He was determined to be keV, by measuring rays for the transition with a high efficiency germanium detector array in coincidence with the He reaction at J-PARC. In comparison to the corresponding energy spacing in the mirror hypernucleus H, the present result clearly indicates the existence of charge symmetry breaking (CSB) in interaction. By combining the energy spacings with the known ground-state binding energies, it is also found that the CSB effect is large in the ground state but is vanishingly small in the excited state, demonstrating that the CSB interaction has spin dependence.