(P,D) REACTION ON N=Z NUCLEI IN 2S-1D SHELL

An investigation of the (p,d) reaction on N=Z nuclei in the 2s-1d shell has been made to obtain spectroscopic information and to study the ln=2 J-dependence for the (p,d) reaction. The experiments were performed with Mg24, Si28, S32, Ar36, and Ca40 as target nuclei, and virtually all of the 2s-1d shell hole strength was observed. Deuteron angular distributions for strongly excited levels in Mg23, Si27, S31, Ar35, and Ca39 were measured for laboratory angles from 10°to 155°, and spectroscopic factors were obtained using distorted-wave Born-approximation (DWBA) calculations. The J dependence for the pickup of an ln=2 neutron appears mostly in the forward angles of the angular distributions and seems to follow systematic trends through the 2s-1d shell, thus suggesting spin assignments for levels in S31, Ar35, and Ca39. Appreciable configuration mixing is found to exist in the ground-state wave functions of all the nuclei investigated. Of particular interest are the ln=1 levels excited in the Mg24(p,d)Mg23 and Si28(p,d)Si27 reactions, which could arise from the removal of either 1p- or 2p-shell neutrons. The ground states of Ar36 and Ca40 are observed to contain appreciable mixing with the f72 shell, and evidence exists for a small [2p]2 admixture in the Ca40 ground state. The level orders of the residual nuclei and the DWBA spectroscopic factors are discussed in terms of the strong-coupling rotational model and Nilsson-model wave functions. Evidence for strong rotational band mixing is apparent in many cases. © 1968 The American Physical Society.