2018 Impact factor 4.843
Particles and Fields
Eur. Phys. J. C 12, 225-241
DOI 10.1007/s100529900228

Measurements of the Z partial decay
width into $c\bar c$ and multiplicity of charm quarks per b decay

The DELPHI Collaboration

P.Abreu 21 - et al.

 21 LIP, IST, FCUL - Av. Elias Garcia, 14-1o, 1000 Lisboa Codex, Portugal

Received: 1 June 1999 / Published online: 8 December 1999

Abstract
The partial decay width Rc of the Z into $c\bar c$ quark pair and the number of charm quarks nc per b decay are measured with the DELPHI detector at LEP 1. Particle identification provides clear D0, D+, Ds+ and $\Lambda_c^+$ signatures. The charm hadron production rate is measured in each channel by a fit to the scaled energy, impact parameter information and the invariant mass spectrum. Two measurements of Rc are presented, from the D*+ production rate and from the overall charm counting, including strange charm baryon production, in $c\bar c$ events. The multiplicity nc, which includes hidden $c\bar c$ and strange charm baryon production, is inferred from the charm counting in $b\bar{b}$ events.
The final results are $R_c = 0.1665 \pm 0.0095$ and $n_c = 1.166 \pm
0.086$.


Copyright Springer-Verlag 2000