Gamow-Teller strengths in A=34 isobars: Comparison of the mirror transitions Tz=+1→0 and Tz=-1→0

With a high energy-resolution of ΔE=21 keV in the S34(He3,t)Cl34 measurement at 0° and at 140 MeV/nucleon, strengths of Fermi and Gamow-Teller (GT) transitions between Tz=+1 and Tz=0 states were studied, where Tz is the z component of isospin T. The corresponding isospin-symmetric transitions connecting Tz=-1 and Tz=0 states can be studied in the Ar34 β+ decay. The strengths of corresponding GT transitions were compared up to the excitation energy (Ex) of 3.1 MeV. A good agreement was observed for the two strong transitions to states around Ex=3 MeV, while a disagreement of 40% was observed for a weaker transition to a low-lying state.