Eur Phys J C (2004) 33: s482-s484
https://doi.org/10.1140/epjcd/s2004-03-1742-y

PS04 Hard QCD

Bottom and charm quark production in two-photon collisions at LEP

LPNHE CNRS/IN2P3 Universités P6 and P7, Paris, France

Received: 14 January 2004
Accepted: 20 January 2004
Published online: 3 March 2004

Abstract

Heavy b and c quark production in γ γ collisions has been measured at LEP. We report here the cross sections measurement and made by DELPHI and L3 Collaboration. Inclusive D ^*± (J/ ψ) has also been studied by L3 (DELPHI). The cross section for b production is found to exceed QCD predictions. The new DELPHI analysis using for the first time K-lepton double tagging in γ γ physics confirms this excess.