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Abstract: Mean lifetime τ of the isomeric state in 12Be has been determined by measuring decay spectra of delayed γ-rays from stopped 12Be nuclei produced by the projectile fragmentation of 18O at 100 A MeV. A consistent value of was obtained from the time spectra of the E2 γ decay to the state and the positron annihilation following the E0 decay to the ground state. Based on the observed branching ratio between the E2 and E0 decays, transition strengths of the two decay modes were deduced to be and , respectively. [Copyright &y& Elsevier]

Abstract: The lifetime of the state at 2.1 MeV in 12Be has been measured using inelastic scattering of a 12Be beam at 43 MeV/nucleon with a gold target. Through the Doppler shift attenuation method, the mean-life of the state has been determined as (syst) ps, which gives a value of in Weisskopf units. The result shows a large quadrupole strength in the ground state transition, providing further evidence on the disappearance of the magic number. The value together with the deformation length measured by proton inelastic scattering yields a neutron quadrupole matrix element two times larger than those for 14C and 16O. [Copyright &y& Elsevier]

Abstract: The neutron-rich nucleus 13B was studied via the proton transfer reaction 4He(12Be, 13Bγ) at . The known 4.83-MeV excited state was strongly populated and its spin and parity were assigned to by comparing the angular differential cross section data with DWBA calculations. This low-lying state is interpreted as a proton intruder state and indicates a deformation of the nucleus. [Copyright &y& Elsevier]

The Coulomb dissociation of 27P was studied experimentally using 27P beams at 57 MeV/nucleon with a lead target. The E2 gamma decay width of the first excited state in 27P was extracted. Assuming the same E2/M1 mixing ratio as the one for the mirror nucleus 27Mg, the gamma decay width of the state, which is of astrophysical interest, is estimated to be ten times smaller than the value calculated by J. A. Caggiano et al. [Copyright &y& Elsevier]

The 1H(27F, 25,26,27F) reactions have been studied at average energy using a liquid hydrogen target. For 25F, 26F and 27F nuclei, we have observed two γ-ray peaks each originating from the decay of two bound excited states. This is the first sign of the existence of bound excited states in 26,27F. The presence of a single bound excited state in 27F is a clear indication of a substantial change in the structure of the fluorine isotopes approaching the neutron dripline. The proposed second excited states in 25,26,27F nuclei have no counterparts in either the or the shell model calculations suggesting the appearance of nuclear structure effects lying out of these model spaces. [Copyright &y& Elsevier]

The energy of the first excited state in the very neutron-rich nucleus 30Ne was determined via proton inelastic scattering. A liquid hydrogen target was bombarded by a radioactive 30Ne beam, and energies of the de-excitation γ rays emitted from excited 30Ne nuclei were measured. The observed transition is likely to be the one from the first 2+ state to the ground state of 30Ne. The excitation energy, 791 (26) keV, is lower than that of 32Mg, indicating an enhancement of deformation as the neutron excess increases in the N = 20 isotones. [Copyright &y& Elsevier]

The energy of the first excited state of the very neutron-rich nucleus 30Ne was determined by proton inelastic scattering. A liquid hydrogen target was bombarded by a beam of radioactive 30Ne at 48 MeV/nucleon, and energies of the de-excitation γ rays emitted from the excited 30Ne were measured. The observed transition is likely to be the one from the first 2+ state to the ground state of 30Ne. The excitation energy, 791(26) keV, is lower than that of 32Mg, indicating enhancement of deformation as the neutron excess increases in the N=20 isotones. The results indicate that 30Ne belongs to the ‘island of inversion’. [Copyright &y& Elsevier]