Production of orbitally excited charm mesons in c and b decays at LEP

A study of the production of L=1 charmed mesons (D** states) has been performed using 4 million Z decays collected by the ALEPH detector at LEP. J/sup P/=1/sup +/ states (D/sub 1/, D/sub s1/) are observed in the decay channel D* pi $9 and D*K respectively, and the J/sup P/=2/sup +/ states (D/sub 2/*, D/sub s2/*) in the channels D* pi , D pi and DK respectively. Since D** states could originate from beauty hadron decay produced in Z/sup 0/ to bb or from charm $9 fragmentation in Z/sup 0/ to cc events, rates are measured separately for b to D/sub 1/, D /sub 2/* D/sub s1/, D/sub s2/* and c to D/sub 1/, D/sub 2/*, D/sub s1 /, D/sub s2/*. (18 refs).