Quadrupole moments and the structure of the even titanium and chromium nuclei

The static quadrupole moments of the lowest 2+ states in 4650Ti and 505254Cr were measured to be -21+-6, 8+-16, -36+-7, -14+-8 and -21+-8e.fm2 respectively. Values for B(E2;01+→21+) of 855+-40, 315+-30, 1020+-40, 660+-30 and 850+-30e2.fm4 were measured for 4650Ti and 505254Cr respectively. Shell-model calculations for these and other f7/2 shell nuclei were compared to the data. The N=26,28 nuclei are adequately described by the shell model if one-particle excitation into the psub(3/2) and f5/2 shells is allowed, but the other nuclei appear to have a more complicated structure. The coexistence model which has been applied to the calcium isotopes is in qualitative agreement with the present results and the assumption that the deformed band moves to a higher excitation energy as N→28. (Auth.)