High-spin states in48Ti

Abstract

The45Sc(α, p γ) reaction has been investigated atE α=11, 12 and 13MeV. Theγ-decay of 198 levels in48Ti up to 8,323 keV excitation energy has been observed. High-spin states were investigated by proton-γ ray angular correlation measurements atE=11 and 13MeV and by DSAM lifetime measurements atE=11 MeV. From the combined evidence spin (-parity) assignments were obtained for the levels atE x =8,323 keV (J= 10,8,6), 8,091(12, 10, 8, 6), 7,668(10, 8), 7,427(9, 7), 7,374(11, 9, 7), 6,906(10, 8, 6), 6,172(8+,6+), 6,102(10+,8+), 6,039(6), 6,034(9+, 7+), 5,630(7), 5,197(8+), 5,169(7+), 5,155(5), 4,404(5), 4,398(6+) and 4,046keV (5). Most of the ambiguous spin assignments become unique if the 8,091 keV level hasJ=12, an assumption which is favoured by its excitation function. The level spectrum thus obtained is well reproduced by shell model calculations in the pure (f 7/2)8 configuration space. Discrepancies exist in the reproduction ofγ-decay modes. The reason is found in low-lying high-spin intruder states which include the 7,427 and 8,323 keV levels. The spectrum of negative-parity states is understood qualitatively by a comparison with46Ti and42Ca.