Precision QCD simulations for the LHC
The improvements of Monte-Carlo event generators in the last decade enable quantitative predictions for the LHC at an unprecedented accuracy.
Combining matrix elements at next-to-leading order in QCD with parton shower emissions (matching) and using (N)LO matrix elements for hard emissions at different final-state multiplicities (merging) led to considerably reduced theoretical uncertainties. There are also ongoing efforts to integrate NNLO matrix elements within these algorithms, reducing the theory inherent uncertainties even more.
However, the evaluation of such advanced QCD predictions needs more and more CPU cycles. Therefore, after reviewing some of these recent developments in the context of the Monte Carlo event generator Sherpa, I will discuss ways for determining those uncertainties efficiently.
The Particle Physics Theory seminar is a weekly series of talks reflecting the diverse interests of the group. Topics include analytic and numerical calculations based on the Standard Model of elementary particle physics, theories exploring new physics, as well as more formal developments in gauge theories and gravity..