Studies Of Triaxiality In Deformed Nuclei And Development Of Relevant Theory

The manuscript contains mainly two parts. In the first part, the roles played by triaxial deformation in low-lying excitation of A ～ 100 nuclei are studied with five-dimensional collective Hamiltonian based on relativistic mean-field theory. In the second part, the detailed framework of axial deformed relativistic Hartree-Fock theory in cartesian coordinate is derived and some preliminary results are presented.Triaxiality in A ～ 100 mass region The low lying excitations of Mo isotopes and N = 60 isotones in A ～ 100 mass region are calculated by using five-dimensional collective Hamiltonian based on functional PC-PK1. By considering γ degree of freedom, the calculations reproduce rather well the systematics of both 2+1energies and B(E2; 2+1â†' 0+1) strengths. It is concluded that the triaxial deformation which is essential to reproduce the data of energies and electric quadrupole transition strengths in low-lying excitations, and also plays an important role in the shape evolution along the isotopic chains.Deformed relativistic Hartree-Fock theory The meson- and coulombpropagators were calculated in cartesian coordinate. It is found that the new method can reproduced accurately the bulk properties like mass, radii, quadrupole deformations of doubly magic nuclei and well deformed isotopes148-160 Nd that calculated in harmonic oscillator basis. Such result verifies the reliability of the new technique for calculation of propagators in cartesian coordinate.