T=0 and T=1 states in the odd-odd N=Z nucleus, 3570Br35 -: art. no. 064307

Excited states in Br-70 were populated in the Ca-40(S-32,pn) reaction at E-beam=80-100 MeV and the Ca-40(Ar-36,alphapn) reaction at E-beam=145 MeV. The resulting gamma decay was detected using the Gammasphere array triggered by a 30-element neutron detector. The cross-bombardment allowed the unambiguous assignment of levels to Br-70, comprising a total of 32 states built both on the J(pi)=0(+) ground state and a previously known J(pi)=9(+) isomer, which is located at an excitation energy of 2293 keV by the observation of linking transitions. The structures are discussed within the context of the two-quasiparticle plus rotor model, the IBM-4 model and the cranked Nilsson-Strutinsky formalism. The nonobservation of a doublet of J=0, T=1 and J=1, T=0 states at low excitation in Br-70 is indicative that T=0 proton-neutron pairing strength is weak in comparison to T=1 pairing.