Single-particle and collective structures in Cr-55 and V-55

TY - JOUR

T1 - Single-particle and collective structures in Cr-55 and V-55

AU - Deacon, A. N.

AU - Steppenbeck, D.

AU - Zhu, S.

AU - Freeman, S. J.

AU - Janssens, R. V. F.

AU - Carpenter, M. P.

AU - Fornal, B.

AU - Honma, M.

AU - Kay, B. P.

AU - Kondev, F. G.

AU - Kozemczak, J.

AU - Larabee, A.

AU - Lauritsen, T.

AU - Lister, C. J.

AU - Robinson, A. P.

AU - Seweryniak, D.

AU - Smith, J. F.

AU - Sun, Y.

AU - Wang, X.

AU - Xu, F. R.

AU - Yang, Y. -C.

PY - 2011/6/7

Y1 - 2011/6/7

N2 - Excited states in V-55 and Cr-55 have been populated via pn and 2n evaporation channels, respectively, following the fusion of a Ca-48 beam at 172 MeV with a Be-9 target. Level schemes have been deduced for the two nuclides to excitation energies of 7467 (V-55) and 12226 keV (Cr-55), with spins of 27/2(+) and 33/2(+), respectively. Negative-parity states are compared with shell-model calculations using three different effective interactions in the full fp model space. Negative-parity levels of Cr-55 are explained in terms of single-particle fp-shell configurations outside N = 28 and N = 32 cores. Positive-parity states in both isotopes show evidence for the involvement of neutron g(9/2) configurations. In the case of Cr-55, a quasirotational structure based on the 1/2(+)[ 440] Nilsson orbital is observed up to the terminating state. In V-55, positive-parity states do not exhibit well-developed collective features, and the observation of octupole decays is an indication of their importance in transitions from neutron g(9/2) configurations to the fp shell. Experimental results are compared with the predictions of a traditional shell model, the projected shell model, and total-Routhian-surface calculations.

AB - Excited states in V-55 and Cr-55 have been populated via pn and 2n evaporation channels, respectively, following the fusion of a Ca-48 beam at 172 MeV with a Be-9 target. Level schemes have been deduced for the two nuclides to excitation energies of 7467 (V-55) and 12226 keV (Cr-55), with spins of 27/2(+) and 33/2(+), respectively. Negative-parity states are compared with shell-model calculations using three different effective interactions in the full fp model space. Negative-parity levels of Cr-55 are explained in terms of single-particle fp-shell configurations outside N = 28 and N = 32 cores. Positive-parity states in both isotopes show evidence for the involvement of neutron g(9/2) configurations. In the case of Cr-55, a quasirotational structure based on the 1/2(+)[ 440] Nilsson orbital is observed up to the terminating state. In V-55, positive-parity states do not exhibit well-developed collective features, and the observation of octupole decays is an indication of their importance in transitions from neutron g(9/2) configurations to the fp shell. Experimental results are compared with the predictions of a traditional shell model, the projected shell model, and total-Routhian-surface calculations.

KW - SHELL-MODEL

KW - ROTATIONAL BANDS

KW - BETA-DECAY

KW - NUCLEI

KW - MASS

KW - CR-54(D,P)CR-55

KW - TERMINATION

KW - ISOTOPES

KW - N=32

UR - http://www.scopus.com/inward/record.url?scp=79961121333&partnerID=8YFLogxK

U2 - 10.1103/PhysRevC.83.064305

DO - 10.1103/PhysRevC.83.064305

M3 - Article

SN - 2469-9985

VL - 83

JO - Physical Review C

JF - Physical Review C

IS - 6

M1 - 064305

ER -