Multiparticle configurations in N = 84 isotones located at the proton drip line

Excited states in the proton-rich N=84 isotones {sub 72}{sup 156}Hf{sub 84}, {sub 73}{sup 157}Ta{sub 84}, and {sub 74}{sup 158}W{sub 84} were observed using {sup 102}Pd({sup 58}Ni, xp2n) reactions at 270 MeV. {gamma} rays were detected with the Gammasphere array of Compton-suppressed Ge detectors coupled with the Argonne fragment mass analyzer and were assigned to individual reaction channels using the recoil-decay tagging method. Prompt {gamma}-ray cascades were associated with the {alpha} decay of both the ground state and the 8{sup +} isomeric state in {sup 156}Hf, the h{sub 11/2} state in {sup 157}Ta, and the 8{sup +} isomeric state in {sup 158}W. The level schemes constructed for {sup 156}Hf,{sup 157}Ta, and {sup 158}W are compared with these of lighter N=84 isotones and are discussed within the framework of the shell model.