E2 moments of the 43 Sc(19/2 - ) and the 43 Ti(19/2 - ) states and the 40 Ca core deformation

Quadrupole coupling constants of the /sup 43/Sc(19/2/sup -/) and the /sup 43/Ti(19/2/sup -/) mirror isomers, implanted into hexagonal Ti, have been measured with the time differential perturbed angular distribution method. Values of e/sup 2/qQ/h=8.5(19) MHz and 8.0(16) MHz are found at room temperature, corresponding to eQ=19.9(14) efm/sup 2/ and 30(7) efm/sup 2/ for the /sup 43/Sc(19/2/sup -/) and the /sup 43/Ti(19/2/sup -/) states, respectively. The isomeric lifetimes were remeasured as T/sub 1/2/=469(4) nsec and 553(21) nsec for the two states. These values, along with transition rates of high spin states in A=42 nuclei were analyzed in terms of effective charges, and were found to be consistent with e/sub n/=0.56(7) and e/sub p/=1.26(9) for the quadrupole moments, e/sub n/=0.65(3) and e/sub p/=1.35(5) for the B(E2) values. The slight increase in the effective charges for the nondiagonal compared to the diagonal E2 matrix elements is understood as the effect of an increased core deformation in the lower spin partner of the transition.