Measurement of the Jet Energy Scale in the CMS experiment ... - IIHE

Chapter 1The Standard Model of ParticlePhysicsElementary particle physics aims to understand the structure of matter at the microscopiclevel and explain the interactions between them. The most thorough theorycurrently known which describes particles and forces is the Standard Model of elementaryparticle physics [1, 2]. Despite of some unanswered questions, the StandardModel has been able to describe the experimental data since it was proposed in sixties.Three out of four interaction forces which have been observed in nature are formulatedwithin the Standard Model. The particles predicted within the model have alreadybeen discovered in research laboratories, except for a missing particle which is themass generator of the model. The heaviest discovered elementary particle is the topquark which was observed in 1995 [3–7] at the Tevatron collider [8]. The parametersof the model have been measured with great precision and efforts are made in order todiscover the last predicted particle of the model, being the Higgs particle. The mostrecent experiment which has been constructed to search for the missing piece of theStandard Model as well as providing answers to other formulated theoretical modelsbeyond the Standard Model, is the Large Hadron Collider (LHC). The two incomingproton beams are currently collided at the center of mass energy of 7 TeV to providethe experimental data for further analysis.In this chapter, the Standard Model of particle physcis is reviewed. The way of formulatingthe particles and forces into the model is described in Section 1.1. Specialemphasis is given to the top quark sector of the Standard Model since the top quarkis the heaviest elementary particle discovered so far with distinct features compared tothe other known elementary particles. Hence, Section 1.2 is dedicated to the physicsof the top quark and elaborates its properties.3