NONRELATIVISTIC LIMIT OF POINT-COUPLING MODEL

The nonrelativistic reduction of the realistic relativistic point-coupling model is performed. The necessity to introduce the nonderivative tensor term is shown. Unfortunately a Galilean-invariant nonrelativistic Hamiltonian density could not be obtained from all terms of the point-coupling model. This fact is due to the nonrelativistic limit of the nonderivative tensor terms which are not Galilean invariant terms in its nonrelativistic forms. The result is compared with that of Skyrme–Hartree–Fock. The role of tensor and nonlinear terms and the average values of the constants in the energy functional of both models are compared and discussed. The nonrelativistic forms of a four-fermion point-coupling model using Hartree and Hartree–Fock approximations are also compared and discussed.

A PROPOSED β-DECAY INTERACTION

It is shown that one can retain the two-component neutrino theory and time reversal with scalar and tensor interactions in the β-decay Hamiltonian, if one postulates that the scalar term produces neutrino emission and the tensor term antineutrino emission. This is consistent with all present experimental data.