409014 SzGeCERN 20161219131716.0 oai:cds.cern.ch:409014 cerncds:FULLTEXT cerncds:CERN:FULLTEXT cerncds:CERN CERN-OPEN-99-343 eng Rousseau, D CERN Study of prompt $J/\psi$ production in hadronic Z decays Study of prompt charmonium production in hadronic Z decay Preprint title 1997 Geneva CERN 19 Aug 1997 15 p A measurement of prompt J/psi production with low model dependence is performed on 3.9 million hadronic Z decays collected by the ALEPH detector. The sample of J/psi at short decay-length shows an excess 46+/-12 prompt J/psi on a background of 57 B decay and 18 combinatorial events, yielding the branching ratio Br(Z->prompt J/psi X)= (3.00+/- 0.78(stat) +/- 0.30(syst) +/- 0.15(theo)) *10^-4. This result is consistent with a theoretical prediction allowing for color-octet gluon->J/psi as well as c quark fragmentation. CERN EDS 991129SLAC SzGeCERN Particle Physics - Experiment CERN PREPRINT CERN LEP ALEPH ALEPH Collaboration EP http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=open-99-343 Access to fulltext document http://cds.cern.ch/record/409014/files/open-99-343.pdf Access to fulltext document http://cds.cern.ch/record/409014/files/open-99-343.ps.gz Access to fulltext document catherine.cart@cern.ch n 199948 11 20101108 1208 CER01 19991123 319858 jerusalem970819 PUBLIC 000335955CER PREPRINT ConferencePaper