Measurements of the CKM angle γ using B + → DK + decays at LHCb

Of the three angles that make up the CKM matrix, the least well known is γ. A precision measurement of this quantity is highly desirable as it forms one of the arbitrary parameters in the Standard Model. Moreover, this is the one angle of the CKM triangle that can be determined in channels that occur via tree-level decays. While loop-level processes could have sensitivity to physics beyond the standard model, tree level processes are expected to be unaltered. Hence a measurement of γ in tree level processes leads to a standard model benchmark measurement against which other loop-driven measurements can be compared. The measurements described here are the latest developments from LHCb involving the decay B → DK, where the D meson is either a D or a D and the final state of the D meson is accessible from either flavour state.