Theoretical study of dynamic behavior of exotic atoms

研究了由^4He、^1H（及其同位素）和μ子组成的总角动量为J=1的μ子分子palphamu的退激x射线谱。结果表明，在palphamu的光谱中存在一个小的第二峰，并且μ子分子的寿命比以前计算的长3倍。我们发现（ddmu）^+有11个J=0和12个J=1的共振态，（dtmu）^+有9个J=0和10个J=1的共振态。相对于介子原子的n=2能级，一些共振能小于D_2的离解能，因此这些态可能在介子催化聚变中起一定作用。利用超径向绝热膨胀方法，研究了dmu + t碰撞的热力学性质。与先前用扭曲原子轨道法计算的结果基本一致。利用满足正确的渐近边界条件的雅可比坐标系，计算了复合介子分子[(dtmu)dee]的形成速率。所得速率比以往的计算大一个数量级，与实验结果一致。利用TCDW方法和第二次玻恩近似计算了正电子形成的截面。

X-ray spectrum due to the deexcitation of a muonic molecule palphamu with total angular momentum J=1 composed of ^4He, ^1H (and its isotopes), and a muon was investigated. It was shown that there is a small second peak in the spectrum of palphamu and the life time of the muonic molecules is three times longer than that determined by a previous calculation. We found 11 resonant states with J=0 and 12 with J=1 for (ddmu)^+, and 9 states with J=0 and 10 with J=1 for (dtmu)^+. Some of the resonant energies, relative to the n=2 level of the muonic atoms, are less than than the dissociation energy of D_2, and therefore these states may play some role in muon-catalyzed fusion. Using the hyperradial adiabatic expansion method, dmu + t collisions are studied at thermal energies. Reasonable agreement with a previous calculation by the distorted-atomic-orbital method was obtained. The formation rate of a complex muonic molecule[(dtmu)dee] was calculated using the Jacobi coordinate system that satisfies the correct asymptotic boundary conditions. The obtained rate is larger than a previous calculation by one order of magnitude and agrees with the experiment. The cross sections for positronium formation were calculated by means of the TCDW method and the second Born approximation.