Deceleration of muonic hydrogen atoms in solid hydrogens

Results of recent calculations of cross-sections for muonic hydrogen atom s cattering in solid hydrogen isotope targets are presented. The coherent par ts of these cross-sections, namely, the elastic Bragg scattering and phonon coherent scattering, are calculated accurately for the first time. A fine structure of Bragg peaks is obtained in the case of Bravais fcc structure o f hydrogen targets frozen rapidly at 3 K. The one-phonon coherent cross-sec tion is estimated using the Debye approximation. The calculated differentia l cross-sections are used for Monte Carlo simulations of muonic atom diffus ion and slowing down in solid hydrogens. Also is calculated the energy-dependent rate of resonant dd mu molecule for mation in 3 K solid deuterium quantum crystal, using the Debye model and Va n Hove's formalism of the response function. This rate is very different fr om that obtained for the 3 K gas model. The influence of d mu atom slowing down on the average dd mu formation rate is considered. It is shown that very slow d mu deceleration below 10 meV i s important for explanation of experimental results.