Construction of the electromagnetic calorimeter detector and study of charmonia production using hadronic final states in the LHCb experiment

Selected topics on the LHCb electromagnetic calorimeter construction and physics analysis are discussed. The document is organised as follows. After the introduction, in chapter 2 the LHCb experiment is described, addressing the experiment operation at the LHC (section 2.1), physics program (section 2.2), and detector issues (section 2.3) describing reconstruction of tracks and vertices, particle identification, trigger and plans for detector upgrade. Then, in chapter 3 the LHCb calorimeters are addressed in section 3.1. Design, construction, quality control and installation of of the LHCb electromagnetic calorimeter detector is discussed in greater detail in section 3.2. Chapter 4 is devoted to charmonium production studies (section 4.1) using decays to hadronic final states in the LHCb experiment. Both prompt production (section 4.2) and inclusive charmonium yield from b-hadron decays (section 4.3) are addressed. Mass of the η_c state is measured using low-background sample of charmonia from b-hadron decays in section 4.4. In chapter 5 measurements of branching fractions for B⁰_s-meson decays to φ mesons, B⁰_s → φφ (section 5.1) and B⁰_s → φφφ (section 5.2), are discussed. Finally, main results are reminded in chapter 6