Effects of Core Polarization and Pairing Correlations on Some Ground-State Properties of Deformed Odd-Mass Nuclei Within the Higher Tamm-Dancoff Approach

In self-consistent mean-field approaches, the description of odd-mass nuclei requires to break the time-reversal invariance of the underlying one-body hamiltonian. This induces a polarization of the even-even core to which the odd nucleon is added. To properly describe the pairing correlations (in T = 1 and T = 0 channels) in such nuclei, we implement the particle-number conserving Higher Tamm-Dancoff approximation with a residual δ interaction in each isospin channel by restricting the many-body basis to two-particle-two-hole excitations of pair type (nn, pp and np) on top of the Hartree-Fock solution. We apply this approach to the calculation of two ground-state properties of well-deformed nuclei |Tz| = 1 nuclei around 24Mg and 48Cr, namely the isovector odd-even binding-energy difference and the magnetic dipole moment, focusing on the impact of pairing correlations