Underlying events in Herwig++

Abstract

In this contribution we describe the new model of multiple partonic interactions (MPI) that has been implemented in Herwig++. Tuning its two free parameters is enough to find a good description of CDF underlying event data. We show extrapolations to the LHC and compare them to results from other models.

4 pages, 3 figures, to appear in the proceedings of the "HERA and the LHC" workshop