par Abreu, Pedro;Vander Velde, Catherine ;Bertrand, Daniel ; [et al.]
Référence Physics letters. Section B, 462, page (425-439)
Publication Publié, 1999
Référence Physics letters. Section B, 462, page (425-439)
Publication Publié, 1999
Article révisé par les pairs
Résumé : | The rate Z → bb̄bb̄ was measured using about 2×106 hadronic decays collected by the DELPHI experiment in 1994 and 1995. Events were forced into 3-jets with ymin > 0.06 and a b-tag was required for every jet. The rate was measured to be: R4b = BR(Z → bb̄bb̄)/BR(Z → hadrons), = (6.0 ± 1.9(stst.)) ± 1.4(Syst.)) × 10-4 where the invariant mass of every bb̄ system is above twice the b quark mass. Using the value of R4b the probability of secondary production of a bb̄ pair from a gluon per hadronic Z decay, gbb, was extracted and found to be: gbb = (3.3 ± 1.0(stat) ± 0.8(syst.)) × 10-3. © 1999 Published by Elsevier Science B.V. All rights reserved. |