A Positive-Weight Next-to-Leading-Order Monte Carlo Simulation of Deep   Inelastic Scattering and Higgs Boson Production via Vector Boson Fusion in   Herwig++
  The positive weight next-to-leading-order matching formalism (POWHEG) is applied to Deep Inelastic Scattering (DIS) and the related Higgs boson production via vector-boson fusion process in the Herwig++ Monte Carlo event generator. This scheme combines parton shower simulation and next-to-leading-order calculation in a consistent way which only produces positive weight events. The simulation contains a full implementation of the truncated shower required to correctly model soft emissions in an angular-ordered parton shower. 
Luca D'Errico and Peter Richardson
hep-ph