HEAVY-QUARK FRAGMENTATION TO POLARIZED QUARKONIUM

We calculate the polarisation of psi's and UPSILON's produced by the fragmentation of heavy quarks. We find that fragmentation to transversely aligned quarkonium is slightly enhanced relative to longitudinally polarised quarkonium. This net alignment corresponds to a approximately 5% asymmetry in the angular distribution of leptons produced in the subsequent decay of the quarkonium. We point out that the leading gluon contribution to psi and UPSILON production arises from the evolution of the charm quark fragmentation function, rather than from direct gluon fragmentation.