A cluster-transfer experiment 9 Be( 9 Be, 14 C * → α+ 10 Be)α was carried out using an incident beam energy of 45 MeV. This reaction channel has a large Q-value that favors populating the high-lying states in 14 C and separating various reaction channels. A number of resonant states are reconstructed from the forward emitting 10 Be + α fragments with respect to three sets of well discriminated final states in 10 Be, most of which agree with the previous observations. A state at 22.5(1) MeV in 14 C is found to decay predominantly into the states around 6 MeV in 10 Be daughter nucleus, in line with the unique property of the predicted band head of the σ-bond linear-chain molecular states. A new state at 23.5(1) MeV is identified which decays strongly into the first excited state of 10 Be.

In a recent breakup-reaction experiment using a Be12 beam at 29  MeV/nucleon, the 0+ band head of the expected He4+He8 molecular rotation was clearly identified at about 10.3 MeV, from which a large monopole matrix element of 7.0±1.0  fm2 and a large cluster-decay width were determined for the first time. These findings support the picture of strong clustering in Be12, which has been a subject of intense investigations over the past decade. The results were obtained thanks to a specially arranged detection system around zero degrees, which is essential in determining the newly emphasized monopole strengths to signal the cluster formation in a nucleus.

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Exclusive cross sections and momentum distributions have been measured for quasifree one-neutron knockout reactions from a 54 Ca beam striking on a liquid hydrogen target at ∼200 MeV=u. A significantly larger cross section to the p 3=2 state compared to the f 5=2 state observed in the excitation of 53 Ca provides direct evidence for the nature of the N ¼ 34 shell closure. This finding corroborates the arising of a new shell closure in neutron-rich calcium isotopes. The distorted-wave impulse approximation reaction formalism with shell model calculations using the effective GXPF1Bs interaction and ab initio calculations concur our experimental findings. Obtained transverse and parallel momentum distributions demonstrate the sensitivity of quasifree one-neutron knockout in inverse kinematics on a thick liquid hydrogen target with the reaction vertex reconstructed to final state spin-parity assignments.

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