Publications (3)0 Total impact
Article: Enhanced collectivity in 74Ni[show abstract] [hide abstract]
ABSTRACT: The neutron-rich nucleus 74Ni was studied with inverse-kinematics inelastic proton scattering using a 74Ni radioactive beam incident on a liquid hydrogen targetat a center-of-mass energy of 80 MeV. From the measured de-excitation gamma-rays, the population of the first 2+ state was quantified. The angle-integrated excitation cross section was determined to be 14(4) mb. A deformation length of delta = 1.04(16) fm was extracted in comparison with distorted wave theory, which suggests that the enhancement of collectivity established for 70Ni continues up to 74Ni. A comparison with results of shell model and quasi-particle random phase approximation calculations indicates that the magic character of Z = 28 or N = 50 is weakened in 74Ni.08/2010;
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ABSTRACT: Proton inelastic scattering on the neutron-rich nucleus 32Mg has been studied at 46.5 MeV/nucleon in inverse kinematics. Populated states were identified by measuring de-excitation γ rays, in which five new states were found by γ-γ coincidence analyses. By analyzing the angular differential cross sections via coupled-channel calculations, their spins and parities were constrained and the amplitudes for each transition were extracted. The spin and parity of the 2321-keV state was assigned as 41+. The ratio between the energies of the 21+ and 41+ states indicates that 32Mg is a transitional nucleus rather than an axially deformed rigid rotor. The collectivities in the nucleus 32Mg with N=20 are discussed based on the results obtained in the present experiment.Phys. Rev. C. 05/2009; 79(5).
Article: Persistent decoupling of valence neutrons toward the dripline: Study of 20C by γ spectroscopy[show abstract] [hide abstract]
ABSTRACT: The very neutron-rich nucleus 20C has been investigated by inelastic scattering on 208Pb and liquid hydrogen targets. Through distorted wave analysis, the reduced electric quadrupole transition probability B(E2;0g.s.+→21+)<18.4 (stat) e2 fm4 and the neutron transition probability Mn2=292±52 (stat) fm4 have been derived. A simple shell model calculation has shown a need for a factor of about 0.4 decrease of the normal polarization charges to elucidate the results. This is interpreted as a decoupling of the valence neutrons from the nuclear core in carbon isotopes heavier than 14C.Phys. Rev. C. 79(1).
Ibaraki, Osaka-fu, Japan
- Research Center for Nuclear Physics