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Gamma rays from 52 Ti have been studied with Gammasphere and the Fragment Mass Analyzer using reactions induced by a 48 Ca beam on a 9 Be target. The data have been used in combination with information from deep-inelastic reactions of 48 Ca beams on a thick 238 U target at an energy about 25% above the Coulomb barrier. The 52 Ti level scheme was expanded considerably, and the lifetimes of some of the identified states were determined for the first time. The excitation of two protons and two neutrons outside the 48 Ca core provide new tests of effective interactions in the full pf -shell model space. The positive-parity states in 52 Ti were compared to theoretical predictions obtained with the GXPF1A, FPD6, and KB3G effective interactions. The comparisons favor, to a degree, the results computed with the GXPF1A interaction. ispartof: Physical Review C, Nuclear Physics vol:80 issue:2 status: published

The low-lying yrast states in the 51 Ca and 52 Sc nuclei were investigated to obtain information on the evolution of the p 1 / 2 and f 5 / 2 neutron single-particle orbitals in neutron-rich nuclei near proton number Z = 20. Level structures associated with neutron excitations into these two orbitals and with proton excitations across the Z = 20 shell gap were identified. Shell-model calculations with the recently proposed GXPF1A interaction account reasonably well for the fp -shell states. The energy separation between the νp 1 / 2 and νf 5 / 2 orbitals in the Ca isotopes appears to be overestimated by the GXPF1A Hamiltonian. ispartof: Physical Review C, Nuclear Physics vol:77 issue:1 status: published

The even 52 – 56 Ti isotopes have been studied with intermediate-energy Coulomb excitation and absolute B ( E 2; 0 + → 2 + 1 ) transition rates have been obtained. These data confirm the presence of a subshell closure at neutron number N = 32 in neutron-rich nuclei above the doubly magic nucleus 48 Ca and provide no direct evidence for the predicted N = 34 closure. Large-scale shell model calculations with the most recent effective interactions are unable to reproduce the magnitude of the measured strengths in the semimagic Ti nuclei and their strong variation with neutron number. ispartof: Physical Review C, Nuclear Physics vol:71 issue:4 status: published

Details regarding the b -decay properties of 54,55,56 Sc are reported and compared with shell model predic- tions. The low-energy level structures of even-even 54,56 Ti are presented, and the systematic variation of the energy of the first excited 2 1 + state is discussed in light of proposed shell closures at N = 32 , 34 for the neutron-rich Ti isotopes ispartof: Physical Review C, Nuclear Physics vol:70 issue:6 status: published

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 56 Sc produced in fragmentation reactions and identified new rays in the daughter N 34 isotone 56 Ti . 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 56 Ti . ispartof: Physical Review Letters vol:92 issue:7 ispartof: location:United States status: published