Search

Under the assumption of good isospin symmetry, Tz = ±3/2 → ±1/2 Gamow-Teller (GT) transitions in a mass A isobar are analogous, where Tz is the z component of isospin T defined by 1/2(N - Z). We studied the Tz = +3/2 → +1/2 GT transitions by using the 37Cl(3He,t)37Ar and 41K(3He,t)41Ca reactions at Ebeam = 140 MeV/nucleon. The GT transition strengths in 37Ar and 41Ca were obtained up to the excitation energy (Ex) of 14.2 MeV and 10.4 MeV with energy resolutions of 30 and 35 keV, respectively. The obtained GT strengths were compared with those of the Tz = -2/3 → -1/2 mirror transitions, measured by the β-decay of 37Ca and 41Ti, respectively. It was found that the overall distributions of the mirror transitions were similar in both A = 37 and A = 41 systems. In A = 37 the differences seen at lower excitation energies are suggested to be the effect of the tensor interaction in the charge-exchange reaction. The differences seen at higher excitation energies are suggested to be the effect of the Coulomb interaction that can break the mirror symmetry of the strength distributions. [ABSTRACT FROM AUTHOR]

Gamow–Teller states, possibly with narrow widths, have been searched for by the 4He(3He, t) reaction with an energy resolution of 100 keV. The search is motivated by theoretical discussions on the role of pions in nuclear structure and simulation of supernovae explosion. In the preliminary analysis of the spectrum at around 0°, no significant narrow structure is observed. [ABSTRACT FROM AUTHOR]

Experimental method of measuring inelastic proton scattering with high-resolution at forward angles including zero degrees has been developed. An energy resolution of 20 keV and a scattering angle resolution of 0.5 degrees have been achieved as well as low background condition and a reliable background subtraction method. The experimental technique was applied to the 12C(p,p′) reaction for studying the property of the second 0+ state at 7.7 MeV and a broad bump around Ex~10 MeV, where the presence of a 2+ state was reported from the 12C(α,α′) measurement. Preliminary spectra and angular distributions are shown. [ABSTRACT FROM AUTHOR]

The cluster structures of the excited states in 11B are studied by analyzing the isoscalar monopole and quadrupole strengths in the 11B(d,d′) reaction at Ed = 200 MeV. The excitation strengths are compared with the predictions by the shell-model and antisymmetrized molecular-dynamics (AMD) calculations. It is found that the large monopole strength for the $3/2^-_3$ state at Ex = 8.56 MeV is well described by the AMD calculation and is an evidence for a developed 2α + t cluster structure. [ABSTRACT FROM AUTHOR]

Studying the Gamow-Teller (GT) transitions of stable as well as unstable pf-shell nuclei is one of the key issues in nuclear and astro-nuclear physics. Under the assumption that isospin T is a good quantum number, symmetry is expected for mirror nuclei and the GT transitions starting from the mirror nuclei. We study the GT transitions starting from Tz = ±1 mirror nuclei, respectively, by means of hadronic (3He, t) charge-exchange reactions and complementary β decays. [ABSTRACT FROM AUTHOR]