Charm decays and $D^{0}-\overline{D}^{0}$ mixing

The LEP1 data sample (4 million hadronic Z decays) recorded by the ALEPH detector is analysed to study charmed particle decays. The measurements of the hadronic branching ratios D/sup 0/ to K/sup -/ pi /sup +/, and of the purely leptonic decays D/sub s/ to tau nu and D /sub s/ to mu nu are presented. The L=1 charmed mesons D** and D/sub s/** are reconstructed in several exclusive decay channels and their production rates are measured. The contributions from charm quark fragmentation and from b hadron decays are disentangled. A study of decays D*/sup +/ to D/sup 0/ pi /sup +/, with D/sup 0/ decaying D/sup 0/ to K/sup -/ pi /sup +/ and D/sup 0/ to K/sup +/ pi /sup -/ is shown. The relative branching ratio B(D/sup 0/ to K/sup +/ pi /sup - /)/B(D/sup 0/ to K/sup -/ pi /sup +/) is measured and the contribution to D/sup 0/ to K/sup +/ pi /sup -/ decay given by D/sup 0/-D/sup 0/ mixing is extracted with a study of D/sup 0/ proper time distribution. (orig.). (13 refs).