Humboldt-Universität zu Berlin - Mathematisch-Naturwissen­schaft­liche Fakultät - Experimentelle Elementarteilchenphysik

Professor represents a systematic approach to the subject of Monte Carlo event generator tuning. The idea is to interpolate the generator response under parameter changes and to fit this approxmiation to high precision data. It is of universal character, i.e applicable to any generator that has an interface to the standard HepMC event record. So far, fortran Pythia has been the focus of our work. Our strategy was to consecutively tune distinct generator aspects one after another. First, we tuned the flavour parameters to LEP-data (multiplicities of identified hadrons + some OPAL spectra). The second stage was to tune fragmentation parameters to general event shape observables (Thrust, etc.) measured by LEP. Recently, we successfully tuned Pythias modeling of the 'Underlying event' (multiple interactions, initial state radiation, beam-beam remnants, colour reconnection) to TEVATRON data (CDF and D0). In general, the Professor tunings yield impressive results compared to both, the quality of and the time spent to achieve the default tunings. The Professor tunings of fortran Pythia have found there way into the release of version 6.4.20, the last release ever.