Physics and detector simulation studies of B-meson decays in ATLAS

This thesis has two objectives; the first is to study the phenomenology of heavy quarks in high energy proton- proton collisions at the Large Hadron Collider (LHC) at the European Laboratory for Particle Physics (CERN). The second objective is to estimate the performance for B- physics analysis of the Inner Tracking Detector in the ATLAS experimental set-up at the LHC. Phenomenological models of B-meson production-asymmetry and prompt J/&psi; production are examined to investigate, and better understand, the different non perturbative QCD models and their description of potential sources of background in CP violation measurements. A Monte Carlo evaluation is made of the precision that can be reached in measurements of CP-violation in the <math> <f> <rm>B⁰<inf>d</inf>&rarr;J/<g>y</g>K⁰<inf> s</inf></rm></f> </math> decay channel as well as of the possibilities of ATLAS to detect physics beyond the Standard Model in the B<super>+</super> &rarr; K<super>+</super>K<super> +</super>&pi;&minus; decay channel. It is shown that after three years of running at low luminosity (30 fb<super>&minus;1</super>) with ATLAS at LHC: (1)&nbsp;a statistical accuracy in the measurement of <italic>sin</italic>2&beta;, &delta;<italic>_stat</italic>(<italic>sin</italic>2&beta;) = 0.010 for an assumed value of <italic>sin</italic>2&beta; of 0.60 can be reached; and (2)&nbsp;an upper limit on R- parity violating couplings &lambda;<super>&prime;</super> can be set:<display-math> <fd> <fl><rad><rcd><fen lp='vb'><sum align='c'><ll>i=1</ll><ul>3</ul></sum> <g>l</g>^&prime;<inf>i32</inf><g>l</g>^&prime;*<inf>i21</inf><rp post='vb'></fen>²+<fen lp='vb'> <sum align='c'><ll>i=1</ll><ul>3</ul></sum><g>l</g>^&prime;<inf>i12</inf><g>l</g>^&prime;*<inf>i23</inf> <rp post='vb'></fen>²</rcd></rad>&lt;5.4&dot;10^-5.</fl> </fd> </display-math>