EXPERIMENTAL SURVEY OF THE STICKING PROBLEM IN MUON-CATALYZED DT FUSION

The ''sticking'' process dtmu --> ap + n, which constitutes the most s evere limit to the number of fusions which a muon can catalyze, is rev iewed. Many attempts were made to determine by calculations and measur ements the probability for initial sticking omega(s)0 (immediately aft er dtmu fusion) and for final sticking omega(s) (after the ag came to rest). Previous results based on neutron disappearance rates and on th e observation of alphamu-X-rays were controversial and also in some di sagreement with theory. New data are reported from PSI on direct obser vation of final sticking, using a setup with the St. Petersburg ioniza tion chamber. These data mark a significant improvement in reliability and may clarify questions concerning previous discrepancies. The new result is omega(s) approximately (0.56 +/- 0.04)%, lower than the theo ry prediction omega(s) = (0.65 +/- 0.03)%, at medium density.