Sum rule study for Double Gamow-Teller states

Abstract

We study the sum rules of double Gamow-Teller (DGT) excitations through double spin-isospin operator $(\sigma t_{-}{)}^2$. In general, $2^{+}$ states in the granddaughter nuclei have dominant transition strength in DGT excitations and $0^{+}$ states are weak, except in $T=1$ mother nuclei in which $0^{+}$ strength is competitive with 2${}^{+}$ strength. The isospin selection of DGT is also discussed among 5 possible isospin states in granddaughter nuclei. A possibility to extract the unit cross section for the DGT transition strength is pointed out in the $(\sigma t_{-}{)}^2$ excitation of double isobaric analog state (DIAS) in $T=1$ nuclei.

Comments: 4pages, Physical Review C, in press(2016)