Measurement of the forward backward asymmetry of c and b quarks at the Z pole using reconstructed D mesons

Collaboration
Jan, 1999

Citations per year

1998200320082013201702468
Abstract:
A measurement of the forward--backward asymmetry of e+eccˉe^{+}e^{-} \to c\bar{c} and e+ebbˉe^{+}e^{-} \to b\bar{b} on the ZZ resonance is performed using about 3.5 million hadronic ZZ decays collected by the DELPHI detector at LEP in the years 1992 to 1995. The heavy quark is tagged by the exclusive reconstruction of several DD meson decay modes. The forward--backward asymmetries for cc and bb quarks at the ZZ resonance are determined to be: \renewcommand{\arraystretch}{1.6} \begin{array}{rcr@{}l} \Afbc(\sqrt{s} = 91.235 {\rm GeV}) &=& &0.0659 \pm 0.0094 (stat) \pm 0.0035 (syst) \Afbb (\sqrt{s} = 91.235 {\rm GeV}) &=& &0.0762 \pm 0.0194 (stat) \pm 0.0085 (syst) \Afbc(\sqrt{s} = 89.434 {\rm GeV}) &=&-&0.0496 \pm 0.0368 (stat) \pm 0.0053 (syst) \Afbb(\sqrt{s} = 89.434 {\rm GeV}) &=& &0.0567 \pm 0.0756 (stat) \pm 0.0117 (syst) \Afbc(\sqrt{s} = 92.990 {\rm GeV}) &=& &0.1180 \pm 0.0318 (stat) \pm 0.0062 (syst) \Afbb(\sqrt{s} = 92.990 {\rm GeV}) &=& &0.0882 \pm 0.0633 (stat) \pm 0.0122 (syst) \end{array} The combination of these results leads to an effective electroweak mixing angle of: SINEFF = 0.2332 \pm 0.0016
  • electron positron: colliding beams
  • electron positron: annihilation
  • Z0: electroproduction
  • Z0: hadronic decay
  • charm
  • bottom
  • quark: pair production
  • particle identification: flavor
  • charmed meson: particle identification
  • angular distribution: asymmetry