Ab initio calculations of Gamow-Teller strengths in the sd shell

Abstract

In the present work we perform a systematic shell model study of Gamow-Teller transition strength distributions in sd shell nuclei using ab initio effective interactions. The ab initio effective interactions are based on in-medium similarity renormalization group (IM-SRG) and coupled-cluster effective interaction (CCEI) approaches. The aim of the present work is to test the predictive power of ab initio effective interactions by using the available experimental data of Gamow-Teller strength distributions in sd shell nuclei. We perform calculations for P, 31 P → 31 Si, and 32 S → 32 P transitions. For comparison we also show the results obtained by using the phenomenological USDB Hamiltonian. The phenomenological USDB results of the Gamow-Teller (GT+/GT−) strength distributions show reasonable agreements with the experimental data in comparison to the ab initio interactions. We also calculate the electron capture reaction rates for 23 Na(e − , ν) 23 Ne and 25 Mg(e − , ν) 25 Na using ab initio and USDB interactions.

Gamow-Teller strengths of some sd-shell nuclei in the shell model framework

“…Our results using USDA and USDB interactions agrees very well with the previous study conducted by [17] using USDA and USDB effective interactions. Also, our work agrees very well with the work of Saxena et al [11] 3 ), respectively. The USDA and USDB interactions predicts correctly the ground state at 4 + which agrees with experimental observation.…”

“…Saxena et al, conducted two ab initio approaches namely: The in-medium similarity renormalization group (IM-SRG) [19] and the coupled-cluster effective interaction (CCEI) to study of the strengths distributions of the transition strength of Gamow-Teller in some selected sd-shell nuclei. They also compared their theoretical results from the two mentioned approaches with the shell model calculations using the phenomenological USDB effective interaction [11]. Zegers et al, studied [12] the 24 Mg( 3 He,t) 24 Al reaction at E( 3 He)=420 MeV.…”

Gamow-Teller excitations at finite temperature: Competition between pairing and temperature effects

“…Among the spin-isospin excitations, the Gamow-Teller (GT) transitions have been extensively studied using different theoretical approaches: the shell model [6][7][8] and the relativistic [9][10][11][12][13][14] and non-relativistic [15][16][17][18][19][20][21][22][23][24] nuclear energy density functionals. For more details on previous studies of the GT transitions within these and other theoretical frameworks, see review articles [25][26][27] and references therein.…”

Ab initio description of collectivity for sd shell nuclei

“…Previously, we have reported electromagnetic properties, Gamow-Teller (GT) strengths and spectroscopic strengths of sd shell nuclei in Refs. [5][6][7].…”