b-tagging in DELPHI at LEPThe DELPHI Collaboration
(Received: 14 January 2003 / Revised version: 14 October 2003 / / Published online: 3 December 2003)
The standard method used for tagging b-hadrons in the DELPHI experiment at the CERN LEP Collider is discussed in detail. The main ingredient of b-tagging is the impact parameters of tracks, which relies mostly on the vertex detector. Additional information, such as the mass of particles associated to a secondary vertex, significantly improves the selection efficiency and the background suppression. The paper describes various discriminating variables used for the tagging and the procedure of their combination. In addition, applications of b-tagging to some physics analyses, which depend crucially on the performance and reliability of b-tagging, are described briefly.
© Società Italiana di Fisica, Springer-Verlag 2004