Nucleosynthesis of gamma-ray emitter Al-26 in the Galxy

γ射线来源于<26>半衰期为72万年的放射性核Al，它的观测是银河系核合成的重要证据。为了再现γ射线的产额<26>，位于γ <26>Al产生级联的旁路序列中的γ Si的激发态信息<26>是非常重要的。在我们目前的伽马射线光谱学研究中，我们在^Si中新观察到一个5889 keV的能级<26>。通过角关联测量，我们确定该能级的自旋宇称为0^+。

Observation of gamma-rays originated from radioactive nucleus <26>^Al, whose half life is 720 thousand yr, is the crucial proof of nuclear synthesis in the Galaxy. In order to reproduce yield of the gamma-rays from <26>^Al, information of excited states in <26>^Si, which is located in bypass sequence of the <26>^Al creation cascade, is quite important. In our present study with gamma-ray spectroscopy, we newly observed one level at 5889-keV in the <26>^Si. Spin parity of this level is determined as 0^+ by our angular correlation measurements.