A study of energy-energy correlations in charged tracks from hadronic decays of the Z0 at 91.2 Gev

[摘要] The energy-energy correlations in charged tracks from the hadronic decays of the Z0 were studied at energies around the Z0-pole of 91.2 Gev. From a comparison with order-alpha-s-squared analytical formulae, the strong coupling constant, alpha-s, was measured. The results obtained wereFrom the EEC:0.132 +/- 0.006 +0.012/-0.009From the AEEC: 0.109 +/- 0.007 +0.011/-0.007where the first error is experimental and the second is due to scale uncertainty.The EEC was also studied for particle clusters and compared with a parton-level Monte Carlo simulation using an exact order-alpha-s-squared matrix element formula. From this study, the value of alpha-s obtained was From clustered EEC: 0.111 +0.016/-0.013An observation of the effects of coherence in b-quark fragmentation was made, leading to evidence in support of the principle of Local Parton-Hadron Duality.An attempt was made to discriminate between samples of quark and gluon jets using the EEC function. No clear conclusion was reached due to limited statistics and the energy mismatch between quark jets and gluon jets.

[发布机构] University:University of Glasgow;Department:School of Physics and Astronomy

[关键词] z0, boson, aleph, alpha-s, eec, strong coupling constant, lep, cern, qcd, strong force, hadron, parton, gluon, quark