Lowest excitations in 56Ti and the predicted N=34 shell closure

Phys Rev Lett. 2004 Feb 20;92(7):072502. doi: 10.1103/PhysRevLett.92.072502. Epub 2004 Feb 20.

Abstract

Recent experimental characterization of the subshell closure at N=32 in the Ca, Ti, and Cr isotones has stimulated shell-model calculations that indicated the possibility that the N=34 isotones of these same elements could exhibit characteristics of a shell closure, namely, a high energy for the first excited 2(+) level. To that end, we have studied the decay of 56Sc produced in fragmentation reactions and identified new gamma rays in the daughter N=34 isotone 56Ti. The first 2(+) level is found at an energy of 1127 keV, well below the expected position that would indicate the presence of an N=34 shell closure in 56Ti.