Neutron-proton pairing and particle-number projection effects on the spectroscopic factor for two-neutron stripping reactions in even-even proton-rich nuclei

摘要

Isovector neutron-proton (np) pairing effect, as well as that of the particle-number projection, on the spectroscopic factor (SF) for two-neutron stripping reactions in even-even proton-rich nuclei are studied. As a first step, expressions of the spectroscopic factor are derived using a schematic definition of the SF proposed by Chasman within the generalized BCS theory and the Sharp-BCS (SBCS) projection method. As a second step, the np pairing and projection effects are numerically studied using the schematic picked-fence model. As a last step, the same effects are numerically studied in the case of proton-rich even-even nuclei using the single-particle energies of a Woods-Saxon deformed mean-field.