Seminarium "Teoria cząstek elementarnych i kosmologia"

In order to study the complex final states of hadron–hadron collisions in great detail, numerical computer simulations using Monte Carlo techniques are the only realistic approach. During the talk, an overview of the physics embodied in the three main Monte Carlo event generators (MCEG) will be given. It will be shown that better control of perturbative QCD corrections leads to the situation in which more often the precision of the LHC measurements is limited by MCEG’s non-perturbative components, such as multiparton interactions (MPI) or hadronisation. New observables which are sensitive to different mechanisms of mini-jet production and MPI physics will be introduced. It will be demonstrated that the Monte Carlo generators show significantly different predictions for the proposed observables, therefore they have the potential to constrain non-perturbative models. Finally, a measurement of the proposed particlerapidity correlations performed by the CMS Collaboration will be discussed.