The impact of tensor force on collective correlations and neutrinoless double-β decay

The tensor force changes the nuclear shell structure, and thus may result in underlying influence the collectivity and decay properties of the nucleus. We carefully examined the impact of the monopole and multipole effects originating from the tensor force on both the collectivity and the matrix element for the neutrinoless double-β (0νββ) decay, using the generator-coordinate method with an effective interaction. To analyze the effect of the tensor force, we employed an effective Hamiltonian associated with the monopole-based universal interaction that explicitly consists of the central, tensor, and spin-orbit coupling terms. The interferences among the shell structure, quadrupole collectivity, nucleon occupancy, and 0νββ matrix elements were analyzed in detail. A better understanding of the tensor force would be of great importance in reducing the theoretical uncertainty in 0νββ nuclear matrix element calculations