TY  - GEN
N2  - This thesis presents a so called same side kaon tagging algorithm, which is used in the determination of the production flavour of B_s^0 mesons. The measurement of the B_s^0 ? B_s^0 bar oscillation frequency ?Delta ms in the decay B_s^0 -> D_s^- ?^+ is used to optimise and calibrate this algorithm. The presented studies are performed on a data set  corresponding to an integrated luminosity of L = 1.0 fb^-1 collected by the LHCb experiment in 2011. The same side kaon tagging algorithm, based on multivariant classifiers, is developed, calibrated and tested using a sample of about 26,000 reconstructed B_s^0 -> D_s^- ?^+ decays. An effective tagging power of ?_eff = ?_tag(1 - 2?)^2 = 2.42 +- 0.39% is achieved. Combining the same side kaon tagging algorithm with additional flavour tagging algorithms results in a combined tagging performance of ?_eff = ?_tag(1 - 2?)^2 = 5.13 +- 0.54%. With this combination, the B_s^0 ? B_s^0 bar oscillation frequency is measured to be ?m_s = 17.745 +- 0.022 (stat.) +- 0.006 (syst.) ps^-1, which is the most precise measurement to date.
TI  - Development and calibration of a same side kaon tagging
algorithm and measurement of the B_s^0 ? B_s^0 bar oscillation frequency ?m_s at the LHCb experiment
ID  - heidok15769
AV  - public
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/15769/
A1  - Krocker, Georg Alexander
Y1  - 2013///
ER  -