A shell-model study of A=48-52 nuclei and magnetic strength distributions in 50Ti

An extensive shell-model calculation has been performed on five fp-shell nuclei in the mass region A=48-52. The model space, which includes 1p-1h excitations, reproduces the experimental spectra very well except for the 02+ state in 50Ti. It is demonstrated that the 02+ state can be reproduced by a model space which also includes 2p-2h excitations. Strong neutron p-h components in the wave functions of states in 2250Ti28 are found despite the closure of the neutron fsub(7/2) orbit. Magnetic transitions in 50Ti are discussed, and in contrast to the 1p-1h results a sufficiently large quenching of B(M1) strengths in the 2p-2h model space is found. Effects of 2p-2h admixtures on M5 transition strengths are discussed as well. (orig.)