Muon capture in hydrogen isotopes

Abstract

After a survey of the phenomenology of muonic hydrogen atoms and molecules recent experiments at SIN are discussed, dealing with muonic atoms and molecules in deuterium. These experiments could clarify the longstanding problem of hyperfine populations of muonic deuterium atoms. For the first time hyperfine transitions in muonic atoms and hyperfine effects in the resonant formation of muonic molecules have been observed. The implication of these new results on weak-interaction rates and the three-body Coulomb problem of muonic atoms are discussed.