Unitary scheme model calculations of the ground and excited state characteristics of3H and4He

Abstract

The ground and excited states of the3H and4He nuclei are studied in the framework of group-theoretical methods. Basis functions of the unitary scheme model corresponding to even numbers of quanta of excitation in the range 0≤N≤20 are constructed for the even-parity states of these two nuclei, and bases with 1≤N≤19 are constructed for the odd-parity states of the4He nucleus. The ground-state and first-excited-state energies and wave functions, the ground S-, P-and D-state probabilities, the root-mean-square radius and the magnetic dipole moment of triton are calculated. Furthermore, for the4He nucleus, the spectrum and the wave functions, the ground S-, P-and D-state probabilities, the root-mean-square radius and the total integral cross section of the dipole electric transition accompanying the photoabsorption of γ quanta by this nucleus are calculated. The GPT and AV8′ two-body interactions and the UIX three-nucleon interaction are used in these investigations. Moreover, the convergence of the calculations is examined by incrementally extrapolating the nuclear characteristics calculated for N≤20 to N=30 for both nuclei.