Remark on Charm Quark Fragmentation To

The observed D mesons have cq̄ flavor quantum numbers and spin-parity of the light degrees of freedom sl l = 3/2 +. In the mc → ∞ limit the spin of the charm quark is conserved and the c → D fragmentation process is characterized by the probability for the charm quark to fragment to a D meson with a given helicity for the light degrees of freedom. We consider the calculated b → B c fragmentation functions in the limit mc/mb → 0 as a qualitative model for the c → D ∗∗ fragmentation functions. We find that in this model charm quark fragmentation to sl l = 3/2 + light degrees of freedom with helicities ±1/2 is favored over fragmentation to sl l = 3/2 + light degrees of freedom with helicities ±3/2. ⋆ Work supported in part by the U.S. Dept. of Energy under Grant no. DE-FG03-92-ER 40701. Heavy quark spin-flavor symmetry[1,2] has important consequences for the spectroscopic properties[3] of hadrons containing a single heavy quark Q. In the mQ → ∞ limit the spin of the heavy quark ~ SQ is conserved. It is convenient for classifying states to introduce the spin of the light degrees of freedom ~ Sl = ~ S − ~ SQ. In the mQ → ∞ limit hadrons containing a single heavy quark Q are labeled by the quantum number sl and these states come in degenerate doublets with total spins s± that arise from combining the spin of the light degrees of freedom with that of the heavy quark