Přehled o publikaci

The unbound nucleus 7He was recently studied in the 2H(6He, 1H) 7He reaction at 29 A MeV beam energy by Golovkov et al. [Phys. Rev. C 109, L061602 (2024)]. The excitation spectrum of 7He was measured up to ET = 8 MeV (ET is energy above the 6He-n threshold). Angular distribution for the 6He-n decay of the 7He 3/2-ground state can be explained by a strong spin alignment induced by a reaction mechanism. The correlation information for the higher-lying 7He excitations is available as backward-forward asymmetry for the 6He-n decay in the 7He frame. The asymmetry function has an expressed energy profile, which may be explained by using quite restrictive assumptions about structure of 7He excitations or/and peculiarities of the reaction mechanism. In the analysis of Golovkov et al. the observation the s1/2 state in 7He is declared with Er 2.0 MeV. Our work is based on the same 7He data. However, the data analysis was improved and also the data interpretation is substantiated with the detailed PWBA reaction studies and coupled-channel calculations of the 7He continuous spectrum. The idea of the s1/2 resonant state with Er 2.0 is rejected. In addition, the position of the 1/2-state in 7He is confined to the interval Er = 2.2-3.0 MeV, with preferred value 2.6 MeV. There is indication on the second 3/2-state in the data with Er 4.5 MeV and with the lower resonance energy limit Er >= 3.5 MeV. Importance and prospects of more detailed correlation studies of 7He continuum are discussed.