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The one-neutron knock-out reaction ¹H(20C, 19Cγ) was studied at RIKEN using the DALI2 array. A γ-ray transition was observed at 198(10) keV. Based on the comparison between the experimental production cross section and theoretical predictions, the transition was assigned to the de-excitation of the 3/21+ state to the ground state. [ABSTRACT FROM AUTHOR]

The unbound excited states of the neutron drip-line isotope 240 have been investigated via the 240(p, p')230 + n reaction in inverse kinematics at a beam energy of 62 MeV/nucleon. The decay energy spectrum of 240* was reconstructed from the momenta of 230 and the neutron. The spin parity of the first excited state, observed at Ex = 4.65 ± 0.14 MeV, was determined to be Jπ = 2+ from the angular distribution of the cross section. Higher-lying states were also observed. The quadrupole transition parameter ß2 of the 2+1 state was deduced, for the first time, to be 0.15 ± 0.04. The relatively high excitation energy and small ß2 value are indicative of the N = 16 shell closure in 240. [ABSTRACT FROM AUTHOR]

One- and two-neutron removal reactions from 19C and 20C have been studied using a liquid-hydrogen target at 40A MeV. A small cross section has been observed in the one-neutron removal reaction from 20C. The observed inclusive removal cross sections are compared with theoretical removal cross sections calculated by using shell model spectroscopic factors and Glauber-model single-particle cross sections. The observed momentum distributions are also compared with those calculated by using continuum-discretized coupled-channel methods. Good consistency between theory and experiment is shown in the one-neutron removal reaction from 19C. However, our theoretical calculation fails to reproduce the neutron removal reactions from 20C, which suggests that further improvements of the theoretical descriptions are necessary. [ABSTRACT FROM AUTHOR]

The exotic decay process of β-delayed fission (βDF) has been studied in the neutron-deficient isotope 230Am. The 230Am nuclei were produced in the complete fusion reaction 207Pb(27Al,4n)230Am and separated by using the GARIS gas-filled recoil ion separator. A lower limit for the βDF probability PβDF(230Am)>0.30 was deduced, which so far is the highest value among all known βDF nuclei. The systematics of βDF in the region of 230Am will be discussed. [ABSTRACT FROM AUTHOR]