QCD studies using a cone-based jet finding algorithm fore+e− collisons at LEP

We describe a cone-based jet finding algorithm (similar to that used in$$\bar p$$p experiments), which we have applied to hadronic events recorded using the OPAL detector at LEP. Comparisons are made between jets defined with the cone algorithm and jets found by the “JADE” and “Durham” jet finders usually used ine+e− experiments. Measured jet rates, as a function of the cone size and as a function of the minimum jet energy, have been compared with O(αs2) calculations, from which two complementary measurements$$\alpha _s \left( {M_{Z^0 } } \right)$$ have been made. The results are$$\alpha _s \left( {M_{Z^0 } } \right)$$=0.116±0.008 and$$\alpha _s \left( {M_{Z^0 } } \right)$$=0.119±0.008 respectively, where the errors include both experimental and theoretical uncertainties. Measurements are presented of the energy flow inside jets defined using the cone algorithm, and compared with equivalent data from$$\bar p$$p interactions, reported by the CDF collaboration. We find that the jets ine+e− are significantly narrower than those observed in$$\bar p$$p. The main contribution to this effect appears to arise from differences between quark- and gluon-induced jets.