The high spin levels in ${}_{}{}^{84}{}_{}{}^{}\mathrm{Sr}$ have been populated through the ${}_{}{}^{59}{}_{}{}^{}\mathrm{Co}$${(}^{28}$Si, 3p) reaction using 98 MeV ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ beam. A regular band structure was found to develop above the ${12}^{+}$ state with a deformation parameter β=0.21±0.04 and γ=8°±6°. The projected Hartree-Fock calculations predict a two proton and two neutron aligned configuration for this band. The predicted quadrupole moment for this configuration is also in good agreement with the experimental values obtained from the lifetime measurements. In addition, a large enhancement in B(M1)/B(E2) transition rates has been observed in the negative parity band above the ${11}^{\mathrm{-}}$ state.

• Received 28 February 1994

DOI:https://doi.org/10.1103/PhysRevC.50.93