Structure of states in 12 Be via the 11 Be(d, p) reaction

The s-wave neutron fraction of the 0 + levels in 12 Be has been investigated for the first time through the 11 Be(d, p) transfer reaction using a 5 A MeV 11 Be beam at TRIUMF, Canada. The reaction populated all the known bound states of 12 Be. The ground state s-wave spectroscopic factor was determined to be 0.28 +0.03 -0.07 while that for the long-lived 0 + 2 excited state was 0.73 +027 -0.40 . This observation, together with the smaller effective separation energy indicates enhanced probability for an extended density tail beyond the 10 Be core for the 0 + 2 excited state compared to the ground state.