I show that with simple extensions of the shower algorithms in Monte Carlo programs, one can implement NLO corrections to the hardest emission that overcome the problems of negative weighted events found in previous implementations. Simple variants of the same method can be used for an improved treatment of matrix element corrections in Shower Monte Carlo programs.
@article{arxiv.hep-ph/0409146,
title = {A New Method for Combining NLO QCD with Shower Monte Carlo Algorithms},
author = {Paolo Nason},
journal= {arXiv preprint arXiv:hep-ph/0409146},
year = {2011}
}