mb(mZ)from jet production at theZpeak in the Cambridge algorithm

We consider the production of heavy quark jets at the Z pole at next-to-leading order (NLO) using the Cambridge jet algorithm. We study the effects of the quark mass in two- and three-jet observables and the uncertainty due to unknown higher-order corrections as well as due to fragmentation. We find that the three-jet observable has remarkably small NLO corrections, which are stable with respect to the change of the renormalization scale, when expressed in terms of the running quark mass at the $m_Z$ scale. The size of the hadronization uncertainty for this observable remains reasonably small and is very stable with respect to changes in the jet resolution parameter $y_c.$