Measurement of the CKM angle gamma and B meson lifetimes at the LHCb detector

LHCb is the dedicated B physics experiment at the Large Hadron Collider (LHC) at CERN. It will make precision measurements of CP violating effects in the Bd and Bs systems, as well as making precision measurements of the lifetimes of all flavours of B hadrons. In this thesis, two possible measurements of the CKM angle gamma are evaluated:from the decay mode B0d -> D- pi+, and from the combined analysis of the decay modes B0d -> D- pi+ and B0s -> D-s K+ under the conditions of U-spin symmetry. Also, a Monte Carlo independent method of measuring the lifetimes of B hadrons is described. The reconstruction of the decay mode B0d -> D- pi+ is studied using the LHCb simulation software, and a general method for categorising background at LHCb is developed. The decay mode B0d -> D- pi+ is found to have a yearly yield of 1340k events, and a signal to background ratio of ~5. It is shown that the analysis of time dependent decay rate asymmetries in B0d -> D- pi+ can result in a precision of ~8 degrees on gamma after one year of data taking. The combined extraction of gamma from the decay modes B0d -> D- pi+ and B0s -> D-s K+ is seen to allow an unambiguous extraction of gamma, with a precision of a few degrees after one year of data taking. The LHCb trigger uses the lifetime of reconstructed particles to discriminate between signal and background, and therefore introduces a bias in the lifetime distributions of B h adrons. A method for measuring this bias, and hence the lifetimes of B hadrons, without recourse to Monte Carlo information, is developed. This method can be applied to any decay mode reconstructed at LHCb which is expected to suffer from a lifetime bias, in particular hadronic decay channels. It is shown that LHCb can expect to match the current world average precision on the B0s lifetime with a few weeks of data taking in the decay mode B0s -> D-s pi+, while the world average precision on the B0d lifetime can be matched with a few months of data taking in the decay mode B0d -> D- pi+.