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Physical Review C, Nuclear Physics

Publication date: 2006-01-01
Volume: 73
Publisher: Published for the American Physical Society by the American Institute of Physics

Author:

Ionescu-Bujor, M
Iordachescu, A ; Napoli, DR ; Lenzi, SM ; Marginean, N ; Otsuka, Taka ; Utsuno, Y ; Ribas, RV ; Axiotis, M ; Bazzacco, D ; Bizzeti-Sona, AM ; Bizzeti, PG ; Brandolini, F ; Bucurescu, D ; Cardona, MA ; de Angelis, G ; De Poli, M ; Della Vedova, F ; Farnea, E ; Gadea, A ; Hojman, D ; Kalfas, CA ; Kroll, T ; Lunardi, S ; Martinez, T ; Mason, P ; Pavan, P ; Quintana, B ; Alvarez, CR ; Ur, CA ; Vlastou, R ; Zilio, S

Keywords:

Science & Technology, Physical Sciences, Physics, Nuclear, Physics, BETA-DECAY, MODEL, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, 5106 Nuclear and plasma physics

Abstract:

The nucleus 31 P has been studied in the 24 Mg( 16 O,2 αp ) reaction with a 70-MeV 16 O beam. A complex level scheme extended up to spins 17/2 + and 15/2 − , on positive and negative parity, respectively, has been established. Lifetimes for the new states have been investigated by the Doppler shift attenuation method. Two shell-model calculations have been performed to describe the experimental data, one by using the code ANTOINE in a valence space restricted to the sd shell, and the other by applying the Monte Carlo shell model in a valence space including the sd - fp shells. The latter calculation indicates that intruder excitations, involving the promotion of a T = 0 proton-neutron pair to the fp shell, play a dominant role in the structure of the positive-parity high-spin states of 31 P.