Multi-jet merging with NLO matrix elements

Abstract

In the algorithm presented here, the ME+PS approach [1] to merge samples of tree-level matrix elements into inclusive event samples is combined with the POWHEG method [2], which includes exact next-to-leading order matrix elements in the parton shower. The advantages of the method are discussed and the quality of its implementation in SHERPA is exemplified by results for e+e− annihilation into hadrons at LEP, for deep-inelastic lepton-nucleon scattering at HERA, for Drell-Yan lepton-pair production at the Tevatron and for W+W−-production at LHC energies.