Observation of inclusive D*+- production in the decay of Upsilon (1S)

Abstract

Bound states of heavy quarks provide a powerful testing ground for quantum chromodynamics (QCD). Experimental studies of charmonium and bottomonium spectroscopy have helped uncover some of the key aspects of the quarkonium potential. Studies of the decays of quarkonia and of their decay products can also reveal important information on QCD processes. The hadronic decays of the narrow quarkonia, states which are below the threshold for open flavor production, are dominated by couplings to gluons and the fragmentation process into light hadrons. The decay properties of charmonia, which have a relatively low multiplicity particle content, have been extensively studied. However, little is known about the final state contents of bottomonia. In particular, scarcely any experimental information exists on the decays of bottomonium to open charm. The CLEO Collaboration has observed charm production in the decays of the b states with branching fractions of the order of 10%. The ARGUS Collaboration searched for the decay Y(1S) -- D+-X and set a limit on its branching fraction of B < 1,9% at 90% confidence level.