Reinvestigation of the level structures of the N =49 isotones( 89)Zr and Mo-91

Excited states of Zr-89 and Mo-91 have been investigated using the fusion reaction Li-6+Y-89 at beam energy of 34 MeV. Based on new experimental data, about 16 (13) new transitions have been added to the level scheme of Zr-89 (Mo-91). The level structures are investigated in the framework of the spherical-basis shell model using the effective interactions JUN45 and GWBXG. Reasonable agreement is obtained between the experimental results and the calculations. The calculated results indicate the newly proposed states are characterized by proton excitations from the 1f(5/2), 2p(3/2), 2p(1/2) orbits to the high-j 1(g9/2) orbit. The systematic features of low lying states in the N=49 isotones are discussed.