Pseudo-SU(4) Symmetry inpf-Shell Nuclei

Abstract

As an alternative to Wigner's spin-isospin SU(4) symmetry, known to be broken in heavier nuclei, a pseudo-SU(4) symmetry is proposed which follows from the combined invariance in pseudospin and isospin. The pseudo-SU(4) scheme is tested in N, Z . 28 nuclei, and its consequences with regard to Gamow-Teller b decay are pointed out. [S0031-9007(99)08617-2]

Microscopic Calculations for Waiting-Point Nuclei

“…The Hamiltonian we used was a G-matrix with a phenomenologically adjusted monopole part [5]. Also, a renormalized version of this interaction in the pf 5/2 space was introduced for describing beta decay [6]. Energy spectra for these two nuclei with both interactions are shown in Figure 1 where a comparison is made between those using the G-matrix and its renormalized version.…”

Pseudo-SU(4) model and beta decay of pf-shell nuclei

“…For the convenience of calculation one may take |i and |f as the normal SU(4) state in the ds shell, provided the GamowTeller operator undergoes a transformation as follows [2],…”

“…A brief analysis in ref. [2] indicates that the pseudo-SU(4) model is promising for describing the pf-shell nuclei.…”

“…the 2p 1 2 -2p 3 2 -1f 5 2 shell) is important for a variety of problems in nuclear structure, however, the study of this shell has been hindered by the huge size of the shell model space. In recent years there have been studies by using the Monte-Carlo shell model [1] and that based on the pseudo-SU(4) symmetry model [2].…”

“…The pseudo-SU(4) model [2] was proposed to deal with the pf-shell by combining the pseudo-spin and the isospin. Since the pseudospin-pseudo-orbit splitting (between 1f 5 2 and 2p 3 2 ) is substantially smaller than the normal spin-orbit splitting (i.e.…”