Angular distributions of decay products of low-lying ⁷ He states populated in the ⁶ He(d,p) reaction

The structure of the 7 He nucleus was investigated in the 6 He(d, p) reaction in inverse kinematics using a 33 MeV/u 6 He beam delivered by the ACCULINNA-2 separator. Angular distributions of the 7 He → 6 He(g.s.) + n decay were measured over a broad excitation energy range of 7 He in the center-of-mass frame with respect to the transferred momentum direction. The data reveal pronounced differences in the angular distribution for different energy intervals. The distribution around 3 MeV shows interference between p 1/2 and 2 s1/2 configurations, while the 4–6 MeV region exhibits features consistent with the presence of a d 5/2 state. These observations suggest the existence of previously unreported components in the excitation spectrum of 7 He.