Bulg. J. Phys. vol.42 no.4 (2015), pp. 523-533

Algebraic Models for Structure of Heavy N=Z Nuclei: IBM-4 Results for Gamow-Teller and α-Transfer Strengths

V.K.B. Kota
Physical Research Laboratory, Ahmedabad 380 009, Gujarat, India
Abstract. Heavy N=Z odd-odd nuclei starting from 62Ga are expected to give new insights into isoscalar vs isovector pairing and also carry signatures of Wigner's SU(4) symmetry. Incorporating these, within the shell model with L-S coupling we have the basic SO(8) algebraic model. With Dyson boson mapping and adding quadrupole degrees of freedom, this model goes over to the algebraic spin-isospin (ST) invariant interacting boson model (called IBM-4) with the bosons carrying (ST)=(10) and (01) degrees of freedom. Using a basis defined by the SOsdST(36) ⊃ SOsST(6) ⊕ SOdST(30) limit of IBM-4, reported here are the formulation and numerical results for (i) Gamow-Teller strengths for β+ decay of 4n+22n+2X2n nucleus with T=1 ground state to the T=0 levels of the odd-odd N=Z 4n+22n+1Y2n+1 nucleus and (ii) α-transfer strengths involving N=Z nuclei. All the numerical results are given as a function of a parameter representing the competition between isoscalar and isovector pairing.

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