Secondary Production of Massive Quarks in Thrust

We present a factorization framework that takes into account the production of heavy quarks through gluon splitting in the thrust distribution for e+ e- --> hadrons. The explicit factorization theorems and some numerical results are displayed in the dijet region where the kinematic scales are widely separated, which can be extended systematically to the whole spectrum. We account for the necessary two-loop matrix elements, threshold corrections, and include resummation up to N3LL order. We include nonperturbative power corrections through a field theoretical shape function, and remove the O(Lambda_QCD) renormalon in the partonic soft function by appropriate mass-dependent subtractions. Our results hold for any value of the quark mass, from an infinitesimally small (merging to the known massless result) to an infinitely large one (achieving the decoupling limit). This is the first example of an application of a variable flavor number scheme to final state jets.