Abstract:
The deformed configurations and rotational band structures in N=50 Ge and Se nuclei are studied by deformed Hartree-Fock with quadrupole constraint and angular momentum projection. Apart from the 'almost' spherical HF solution, a well-deformed configuration occurs at low excitation. A deformed well-mixed Ω = 1/2+ neutron orbit comes down in energy (from the shell above N = 50) to break the N = 50 spherical shell closure. A K = 7-isomer is predicted in Se at fairly low excitation energy. At higher excitation energies (8 MeV), a deformed band with Ω = 7/2+-1/2- (based on h11/2) neutron 1p-1h excitation, for 82Ge and 84Se, is shown in our calculation. Our study gives insight into possible deformed structures at spherical shell closure.
