
Abstract 
In order to study the GamowTeller (GT) transitions from the Tz = +2 nucleus Ca44 to the Tz = +1 nucleus Sc44, where Tz is the z component of isospin T, we performed the (p, n)type (He3, t) chargeexchange (CE) reaction at 140 MeV/nucleon and the scattering angles 0 degrees and 2.5 degrees. An energy resolution of 28 keV, that was realized by applying matching techniques to the magnetic spectrometer system, allowed the study of fragmented states. The GT transition strengths, B(GT), were derived up to the excitation energy (Ex) of 13.7 MeV assuming the proportionality between cross sections and B(GT) values. The total sum of B(GT) values in discrete states was 3.7, which was 31% of the sumrulelimit value of 12. Shell model calculations using the GXPF1J interaction could reproduce the gross features of the experimental B(GT) distribution, but not the fragmentation of the strength. By introducing the concepts of isospin, properties of isospin analogous transitions and states were investigated. (i) Assuming isospin symmetry, the Tz = +2 > +1 and Tz = 2 > 1 mirror GT transitions should have the same properties, where the latter can be studied in the beta decay of Cr44 to V44. First, we confirmed that the betadecay halflife T1/2 of Cr44 can be reproduced using the B(GT) distribution from the Ca44(He3, t) measurement. Then, the 0 degrees, (3He, t) spectrum was modified to deduce the “betadecay spectrum” and it was compared with the delayedproton spectrum from the Cr44 beta decay. The two spectra were mostly in agreement for the GT excitations, but suppression of the proton decay was found for the T = 2 isobaric analog state (IAS). (ii) Starting from the T = 2 ground state of 44Ca, the (3He, t) can excite GT states (state populated by GT transitions) with T = 1, 2, and 3. On the other hand, the Ca44(p, p') reaction can excite spinM1 states (states populated by spinM1 transitions) with T = 2 and 3 that are analogous to the T = 2 and 3 GT states, respectively. By comparing the spectra from these two reactions, a T value of 2 is suggested for several GT states in the Ex = 11.513.7 MeV region. (iii) It has been suggested that the T = 2, J(pi) = 0(+) double isobaric analog state (DIAS) at 9.338 MeV in the Tz = 0 nucleus Ti44 forms an isospinmixed doublet with a subsidiary 0(+) state at 9.298 MeV. Since no corresponding state was found in the Tz = +1 nucleus Sc44, we suggest T = 0 for the subsidiary state. 
