Study Of Anomalous Gauge Boson Couplings At The LHC

One of the ways of investigating theories beyond the SM is to examine anomalous gauge boson couplings determined by non-Abelian S UL(2) ? UY(1) gauge symmetry using effective Lagrangian. Anomalous quartic gauge coupling γγW+W-is one of the most promising channels to look for signals of new physics. Any deviation of the quartic gauge boson couplings from the prediction of SM would imply the existence of new physics beyond the SM. The most recent experimental search for anomalous quartic γγW+Wcoupling is done by CMS where they have used equivalent photon approximation(EPA)method to calculate the elastic process and then using the experimental data extracted factor to account for the proton dissociative contribution. On the other hand, with the increasing requirement on precision calculation of the events in the present colliders, various PDF groups are including photon flavour in their PDFs, hence opening a new gate for studying photon processes in proton proton collisions.We study the anomalous quartic gauge coupling γγW+W-using photon PDF and,with some simplifications, estimate the sensitivity of LHC at 13 Te V. To achieve this, first we have discussed the standard model of particle physics, which provided us with a theoretical basis for understanding the extension of the standard model and basic knowledge about phenomenology. We also discussed the effective field theory approach and various anomalous gauge coupling operators. With the understanding of the standard model and the effective field theory approach we have introduced the basics of phenomenology including the way we connect theory to experimental result. At the end we have built our own model with includes the anomalous quartic gauge coupling, and carried out related calculations via Monte-Carlo method and performed a simple simulation of particle collisions. We have used photon PDF and EPA to describe the photon from proton. Our result shows that the signal of the process that is described by photon PDF is increased compared to the result of EPA, for the PDF describes the inclusive process that includes inelastic processes and the EPA only describes the elastic process. Therefor, we get a stronger limit on anomalous coupling.