Isospin symmetry-structure study at new high-resolution course of RCNP

By comparing IE type data from γ decay and (p,p′) reaction with the data from CE type (³He, t) reaction, we have shown that the isospin symmetry structure exists up to E_x = 16 MeV in the mirror nuclei ²⁷Al-²⁷Si. In addition, from the analysis of different transition strengths in (p,p′) and (³He, t) reactions to analogous final states, isospin values could be assigned to highly excited states. Good resolution was important to assign the corresponding (analogous) states in hadron reactions at intermediate incident energies, where it is known that 0° cross sections are proportional to B(GT) values. The resolution in the CE type reaction was drastically improved by using the (³He, t) reaction in combination with beam matching techniques. At RCNP a new beam line WS-course, which fully allows the realization of several matching conditions with the existing spectrometer, was commissioned. A resolution of 50 keV has been achieved for an incident energy of 150 MeV/nucleon and a better resolution is still expected. Good angle resolution realized simultaneously is also important for the selection of specific L states. We believe these high resolutions now available will open a new dimension not only in the spectroscopic study of spin excitations, like the study of isospin symmetry structure presented here, but also in better understanding the problems related with interactions through the separation of specific states of interest.