抄録
Exotic atoms are the interesting object as a new probe in material science and a new chemical species in future chemistry. Our group (πAX) has recognized the mesoatomic and mesomolecular phenomena as a subject of chemistry, and continued the experimental study for the capture process of negative pions since 1982. In the recent study, we have investigated the pion capture process mainly in liquid and gas phases, focusing to the behavior of pionic hydrogen atoms. A novel method to measure selectively the pion capture for a particular hydrogen in a molecule revealed the effect of the chemical state of the hydrogen on the transfer process. A proposed model, which combines a LMM model with a transfer process, was useful to wholly understand the capture process observed. The outline of the formation process of pionic atoms and its behavior in material is described briefly, and the main results of our studies are reviewed.
