Halo-like structure in 7He nucleus

A study of the neutron structure of the ground state of 7He has been performed by means of registration and analysis of the decay channels of the residual nuclei following absorption of stopped pions. In particular, the reaction 9Be (${\pi }_{}^{-},d$)X have been investigated where X denotes any system with five neutrons and two protons – the constituencies of a 7He nucleus. It was shown that the structure of 7He is determined by correlations of two neutrons in the states 6He (0+), 6He (2+) and one neutron in the shell p3/2. The 4He+3n structure is not manifested in the ground state of 7He. The obtained results are consistent with the known data on considerable mixture of configurations "6H…