Measurement of the multiplicity of gluons splitting to bottom quark pairs in hadronic Z(0) decays

An inclusive measurement of the average multiplicity of b (b) over bar pairs from gluons, g(b (b) over bar), in hadronic Z(0) events collected by the DELPHI experiment at LEP, is presented. A counting technique, based on jet b-tagging in 4-jet events, has been used. Looking for secondary bottom production in events with production of any primary flavour, by requiring two b-tagged jets in well defined topological configurations, gave g(b (b) over bar) = (0.21 +/- 0.11(stat) +/- 0.09(syst))%. This result was checked with a different method designed to select events with four b quarks in the final state. Agreement within the errors was found. (C) 1997 Elsevier Science B.V.