Determination of GT-transition Strengths in $A=34$ Isobars Using Charge Exchange $(^3\text{He},t)$ Reaction

Abstract

Under the assumption that isospin $T$ is a good quantum number, mirror transitions $T_{z }= +1 \to  0$ and $T_{z }= -1  \to  0$ were studied in $A = 34$ isobars, where $T_{z}$ is $z$ component of iospin $T$ and is defined by $T_{z} = (N-Z)/2$. With a high energy resolution of 35 keV in $^{34}$S$(^{3}He,t)^{34}$Cl reaction measurement at $0^{\circ}$ scattering angle and at an incident energy of 140 MeV/nucleon, strengths of Fermi and Gamow-Teller (GT) transitions from the $J^{\pi } = 0^{ + }$, $T_{z }= +1$ ground state of $^{34}$S to the $J^{\pi } = 1^{+ }$, $T_{z }= 0$ excited states in $^{34}$Cl were determined up to excitation energy $(E_{x})$ of $7.08$ MeV. The corresponding isospin-symmetric transitions connecting $T_{z }= -1$ and $T_{z }= 0$ states can be studied in the $^{34}$Ar $\beta ^{ + }$ decay. The strengths of the $(GT)_{\pm }$ transitions were compared up to the excitation energy of 3.1 MeV. A good agreement was observed for two strong transitions to $2.580$ MeV and $3.129$ MeV states, while a disagreement about $45\text{%}$ was observed for a weaker transition to $0.666$ MeV low-lying state.