  A new paradigm for nuclear structure that includes blocking effects of tensor
interactions is proposed. All of the recently discovered magic numbers (N=6,
14, 16, 32 and 34) in neutron-rich nuclei can be explained by the blocking
effects. A large amount of binding energy is gained by high-momentum correlated
pairs of nucleons produced by the tensor interaction. Such tensor correlations
strongly depend on the configuration space available for exciting nucleons to
2p-2h states. When additional neutrons occupy a new orbital, the previously
available configuration may be lost, resulting in a sudden loss of binding
energy otherwise gained by the 2p-2h excitations. Such tensor blocking effects
enlarge the energy gaps at all observed new magic numbers. Tensor blocking also
explains consistently the observed peculiar configurations of neutron-rich
nuclei at the borders of shells.
