Isospin-spin responses in charge-exchange exothermic reactions

利用类时区不稳定束的放热电荷交换(CE)反应，研究了原子核高激发态下的自旋-同位旋响应。为了实现这一研究，设计并建造了高分辨率磁谱仪Sharaq。Sharaq安装在RIKEN Nishina中心的RIBF中。对一种新的自旋模式进行了探索，发现了β等矢量自旋单极共振。用(p，n)和(n，p)反应研究了2v2β衰变的核基质元素^&lt；48&gt；Ca和^&lt；116&gt；Cd。一旦发现0V2β衰变，所获得的NME将在确定中微子质量方面起到决定性作用。

Spin-isospin responses in highly excited state of nucleus are studied by the exothermic charge-exchange(CE) reaction with unstable beam in the time-like region. To realize the study the high resolution magnetic spectrometer SHARAQ was designed and constructed. The SHARAQ was installed in the RIBF of RIKEN Nishina Center. A search for a new spin mode was made and theβ+ isovector spin monopole resonance was found. The nuclear matrix elements(NME) for the 2v2βdecay, ^<48>Ca and ^<116>Cd, were studied by the (p,n) and (n,p) reactions. Obtained NMEs will play a decisive role in the determination of neutrino mass once 0v2β decay were found.