P. Tortosa

Mass effects in the emission of gluons from heavy quarks at high energies

The effects in the emission of gluons due to the mass of the heavy quarks have clearly been observed by the experiments at LEP and SLC. The analyses of the data using theoretical corrections computed at Next-to-Leading Order have allowed to either test the flavor independence of the strong coupling constant with very high precision (∼ 1%) or measure the b-quark mass at high energy, s∼MZ. The results obtained by the various experiments, ALEPH, DELPHI, OPAL and SLD, agree well within errors. The systematic uncertainties limit present determinations though new methods and strategies are being developed to overcome the present bounds.

Determination of the b-quark mass at LEP and SLC

Several hadronic event shape observables at LEP and SLC are sensitive to the b-quark mass through the reduced gluon radiation which occurs compared to lighter flavours. Detailed measurements by ALEPH, DELPHI, OPAL and SLD collaborations at √ s = MZ have established the effect and have enabled determinations of the b-quark mass at this energy scale. The most recent results are presented and discussed.