Updated studies of determining gamma at LHCb with the decays $B^{+-} \to D(K\pi,KK,\pi\pi)K^{+-}$

The selection efficiencies and backgrounds for the decays B+- -> DK+-, where the D denotes a D0bar or D0 which decays into the two-body final states Kpi, KK, pipi, are determined from simulation studies. These are used to estimate the precision with which LHCb will be able to measure the CKM angle gamma. With a data set corresponding to an intergrated luminosity of 2fb-1, a precision of 9.9-11.3 degrees is expected, depending on the strong phase difference between D0 -> K+pi- and D0->K-pi+ decays.