(d, t) and (d,He3) Reactions on

Abstract

He 3 )K 42 , and Ca 44 (d, He 3 )K 43 reactions have been investigated at an incident deuteron energy of 22 MeV. The angular distributions have been compared with distorted-wave calculations and the spectroscopic strength has been extracted. The larger fraction of the &m strength was found in the f + states at 2.02, 0.99, 1.89, and 2.60 MeV in Ca 41 , Ca 43 , Ca 45 , and Ca 47 , respectively. Strong s-wave transitions were observed to levels at 1.96, 2.40, and 2.60 MeV in Ca 43 , Ca 45 , and Ca 47 , respectively. The % + hole state at 2.67 MeV in Ca 41 was found to be less pure than the other strong s-and d-hole states. Similarly, a pronounced fractionation of the s-hole configuration among the levels at 0.982, 1.273, 1.595, and 2.73 MeV was found in K 41 -in contrast with the other even-parity hole states in K 41 and K 43 (including the J + level at 0.56 MeV), which are rather pure. This splitting is attributed in part to the interaction of another J + state with the s-proton hole state. Some 2ps/2 admixture was observed in each of the neutron pickup reactions and a 2pi/2 admixture was seen in Ca 48 . Comparison between the relative intensities of the transitions to the f~ levels in Ca 41 and Ca 43 and those of the (d t p) reactions to those levels suggest the admixture of core-excited configurations in the ground state of Ca 42 and Ca 44 . The upper limit for the /7/2-proton admixture in the ground state of Ca 42 was found to be C 2 S<0.4. The second 0 + state in Ca 42 is excited with about 10% of the strength of the first 0 + state. The strength of the transitions to the 0 + and 2 + states together with those of the 4 + and 6 + states is significantly smaller than expected from simple shell-model considerations and suggests that other levels with (fm) 2 configurations exist in Ca 42 at higher energies. The /=0 transitions to states in Ca 42 rarely mix with the 1 -2 transitions. There is a fairly good correspondence between the $-hole states and the 3" states. Application of the sum rule and comparison with the other reactions suggest that the total spectroscopic factor for su 2 , T-l pickup is considerably smaller than would be expected from a closed 2s shell. The four lowest levels in K 42 have / = 2 transitions and the strengths are in agreement with a 2"~, 3", 4", 5~ sequence. In addition, s-proton hole states in K 42 were observed at 1.2, 2.01, and 2.13 MeV. A possible d 5 /2-hole state was found in K 41 at an excitation energy of 3.566 MeV.