LHCb

Abstract:

A combination of recent LHCb results is used to perform a measurement of the CKM angle γ We use B^± → Dk^± and B^± → D^π± decays where the D meson (D⁰ or D̄⁰) decays into KK, ππ, Kπ, KS⁰π π, KS⁰KK, or Kπ π π final states. Using only B^± → Dk^± results, we find a best-fit value of γ = (71:1 -15:7 ^+16:6): For the first time information from B^± → D^π± decays is included in a combination. When these results are included, the best-fit value becomes γ = 85:1 and we set confidence limits of γ ε [61:8; 67:8]° or [77:9; 92:4]° @68% CL; γ ε [43:8; 101:5]° @95% CL: All values are modulo 180°.

Abstract:

This contribution reports on recent LHCb achievements in the pursuit of CKM triangle measurements and probes of CP violation in the charm system. These results are based on the 2010 dataset or, in some cases, preliminary results using the data collected by summer 2011. © Owned by the authors 2012.

Abstract:

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 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 D0 or a D̄0 and the final state of the D meson is accessible from either flavour state.