Measurement of the fraction
of hadronic Z decays into charm quark pairs
The ALEPH Collaboration
R. Barate - et al.
Laboratoire de Physique des Particules (LAPP), IN2P3-CNRS, F-74019 Annecy-le-Vieux Cedex, France
Received: 6 March 1998 / Published online: 2 July 1998
The full statistics of hadronic Z decays collected with the ALEPH detector are analysed to measure, by three methods, the ratio, , of the partial decay width of the Z into quarks to the total hadronic width. One method uses the inclusive p and spectra of electrons. The other two use a double-tagging technique to measure independently of the charm-tagging efficiency. In one, the tagging procedure uses the reconstruction of high momentum charmed mesons (, and ) to detect the charm quarks. In the other, a charm quark is tagged from the 's reconstructed in the decay channel and the other from the slow pion from the decay. The combination of these measurements leads to .