Exact Differential O(alpha**2) Results for Hard Bremsstrahlung in e+e- Annihilation to 2f At and Beyond LEP2 Energies

摘要

We present the exact O(alpha) correction to the process e+ e- -> f f-bar +gamma, f neq e, for ISR oplus FSR at and beyond LEP2 energies. We give explicitformulas for the completely differential cross section. As an importantapplication, we compute the size of the respective sub-leading corrections ofO(alpha L) to the f f-bar cross section, where L is the respective biglogarithm in the renormalization group sense so that it is identifiable as L =ln |s|/m_e^2 when s is the squared e+e- cms energy. Comparisons are made withthe available literature. We show explicitly that our results have the correctinfrared limit, as a cross-check. Some comments are made about theimplementation of our results in the framework of the Monte Carlo eventgenerator KK MC.