The jet multiplicity as a function of thrust

We calculate the average multiplicity of jets in e+e− annihilation as a function of both the jet resolution parameter, ycut, and the thrust T. Our result resums to all orders the leading and next-to-leading logarithms in ycut and 1−T, and is exact up to second order in αS. This allows a comparison between the number of jets found using jet algorithms and the ability to distinguish different jet topologies via thrust.