Speaker
Description
The parton shower beyond the leading order is the next step to improve our
understanding of hadronic final states in collider experiments. This is rather challenging since we have to deal with
more Feynman graphs and more complicated integrals. At first order level the parton shower algorithm is rather
intuitive but higher order level the quantum interference are more important and it cannot be understood based on
classical or semi-classical probabilities. We need a general definition of the parton showers at all order level. For
this we introduce the concept of infrared renormalization and the shower cross sections are defined as the solution of
the corresponding renormalization group equations. In this talk we also discuss the mathematical framework of the
parton shower evolution that is adequate to go beyond the leading order.