Measurement of sin(2β) with the CMS detector at LHC

For this study the author explored the possibility to determine CP-violation by measuring the time-integrated asymmetry in B0d, bar B0d→J/ψK0S decays, to determine the angle β of the unitarity triange. The time-independent asymmetry A for this channel is: A= sin(2β)(xd/(1+xd2)), where xd has been measured to be 0.71. Because of the mixing phenomena, the nature of the B0d (particle or antiparticle) has to be determined. This can be done by measuring the charge of the μ± in the semileptonic decay of the associated beauty hadron (b→μ-X). The CMS (Compact Muon Solenoid) is designed as a general purpose detector for discoveries at the highest luminosity in proton-proton collisions at LHC. However, during the initial period of LHC operation, it is expected that there will be an opportunity to carry out heavy flavour studies, such as CP-violation, at lower luminosity. Here the author concentrates on the detector parts most important for measuring CP-violation, i.e. the muon-system, the muon trigger and the inner tracker