The parton shower in Herwig is the product of many years of continuous development and its main purpose is to evolve the event from the hard energy scale to an infrared cutoff scale where non-perturbative hadronisation models take over. The next step in development of the shower is to include higher orders to increase the logarithmic accuracy. This requires the implementation of splitting functions for two or more emissions which involves the organisation and bookkeeping of the singularity structures of QCD cross sections. These higher order calculations are to be implemented in a methodical and algorithmic manner to allow for efficient computing. The soft and collinear limits are often treated separately however, it has been one goal of this project to look at the cross over between these two limits and the details of the relevant singularities as this includes a much wider region of phase space. The overall aim is to develop a higher order parton shower that can be implemented in Herwig and will improve the accuracy of the event simulation.
Emma Simpson Dore
September, 2018 to December, 2018