e+e−→Z0Z0→bbcc events as model independent probe of colour reconnection effects

According to the basic properties of QCD, colour reconnection effects can occur in hadronic processes at high energies. The comparison of e+e−→Z0Z0→qqq′q′ events with the superposition of Z0→qq and Z0→q′q′ events from LEP1 would provide an unambiguous model-independent probe. We show that at LEP2 energy, the background processes are negligible if we select only e+e−→Z0Z0→bbcc events, and limit the measurements in the phase space of on-shell Z0Z0 events.