The angle gamma is the least constrained parameter in the CKM unitarity triangle. Its determination in decays induced by tree-level b -> u transitions is largely unaffected by potential new physics contributions. This allows for a consistency check of the unitarity triangle, but also of comparisons with gamma determinations from modes with loop-diagrams. We present here a new precise determination of gamma using a time-dependent flavour-tagged analysis of Bs -> Ds K decays with the LHCb experiment. New developments in flavour tagging are presented.
M. Mangano, C. Lourenco, G. Unal......................... Tea and Coffee will be served at 10h30