Electrons from charm and beauty quarks in proton-proton collisions with ALICE at the LHC and study of collective flow in low energy heavy-ion collisions

Abstract

In this chapter, a brief introduction to the high energy physics in the context of this thesis is given. This includes a short overview of the standard model, the formation of Quark-Gluon Plasma, its evolution and ways to probe it in the heavy-ion experiments. 1.1 Standard Model Matter around us is built from elementary particles and interactions among them. As per the traditional wisdom, there are four fundamental forces that exist in nature viz. Strong, Electromagnetic, Weak and Gravitational force. The standard model is a theory which encapsulates these fundamental interactions except gravitational force. The fundamental particles can be characterized by their intrinsic properties such as, spin, baryon number, lepton number, electric and color charge etc. As shown in Figure 1.1, the particles and their anti-particles can be broadly classified into two groups, fermions and bosons according to their spin quantum number. Quarks and leptons are fermions. There are six quarks (up (u), down (d), strange (s), charm (c), bottom (b) (or beauty) and top (t)) and their anti-quarks, each with three color (red, green and blue) and their corresponding anti-color charges as an additional quantum number [1, 2]. There are three generations of quarks (leptons) in which up and down (electrons (e) and electron neutrino (νe)) being the first generation of quarks (leptons), strange and charm (muon (µ) and muon neutrino (νµ)) being the second, and top and bottom (tau (τ) and tau neutrino (ντ )) are the third generation of quarks (leptons).