Effects of jet algorithms from higher order QCD in W± mass determinations at LEP2

We analyse the impact of systematic effects due to the scale dependence ofQCD corrections in combination with the use of different jet clusteringalgorithms in the measurement of the $W^\pm$ mass in the fully hadronic decaymode of $W^+W^-$ pairs produced at LEP2. We consider higher order contributionsinduced by both virtual and real gluon radiation onto the electroweak CC03 andCC11 channels through ${\cal O}(\alpha_{s})$ at the parton level. We find thatthe associated uncertainties can be of order 100 MeV, thus competitive withthose possibly arising in the non-perturbative regime and indeed above thecurrent experimental estimates.