The Standard Model (SM) is a theory describing fundamental particles and the interaction between them. These fundamental particles are all fermions, having spin 1/2, and are grouped into three so called generations. There are nine quarks, which have a charge of either -1/3 or 2/3 and nine leptons, which consist of three massive leptons, the electron, the muon and the tau and their respective neutrinos. The force carriers called the gauge bosons, all have spin 1. The massless photon is the mediator of the electromagnetic force, the massless gluon is the mediator of the strong force and the massive W+- and Z bosons are the mediators of the weak force. Latest results from ATLAS and CMS prove the existence of a Standard Model Higgs boson, a scalar boson with spin 0, which give mass to the fermions and the gauge bosons.
What we are working on
Analysis of Wyy final states
While diboson final states have already been measured at the LHC, the dataset has so far been too small to study final states containing three vector bosons. The signature comprising one W boson and two photons will be among the first triboson final states to be detected by ATLAS. The extraction of the cross section will be unprecedented as it is so small, that it couldn't be measured by previous experiments. A very attractive feature of studying the Wyy final state is, that it is sensitive to the so called quartic gauge couplings, describing a four vector boson interaction. This is due to the fact that the process pp -> Wyy comprises four boson vertices. The gauge couplings are precicely described by the Standard Model of particle physics and a deviation from these predictions would hint to new phenomena aside from the to date established theory.