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Register a new userMeasurement of the CKM angle $gamma$ from a combination of LHCb results
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A combination of measurements sensitive to the CKM angle $gamma$ from LHCb is performed. The inputs are from analyses of time-integrated $B^{+}rightarrow DK^+$, $B^{0} rightarrow D K^{*0}$, $B^{0} rightarrow D K^+ pi^-$ and $B^{+} rightarrow D K^+pi^+pi^-$ tree-level decays. In addition, results from a time-dependent analysis of $B_{s}^{0} rightarrow D_{s}^{mp}K^{pm}$ decays are included. The combination yields $gamma = (72.2^{+6.8}_{-7.3})^circ$, where the uncertainty includes systematic effects. The 95.5% confidence level interval is determined to be $gamma in [55.9,85.2]^circ$. A second combination is investigated, also including measurements from $B^{+} rightarrow D pi^+$ and $B^{+} rightarrow D pi^+pi^-pi^+$ decays, which yields compatible results.
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A combination of three LHCb measurements of the CKM angle gamma is presented. The decays B->DK and B->Dpi are used, where D denotes an admixture of D0 and D0-bar mesons, decaying into K+K-, pi+pi-, K+-pi-+, K+-pi-+pi+-pi-+, KSpi+pi-, or KSK+K- final states. All measurements use a dataset corresponding to 1.0 fb-1 of integrated luminosity. Combining results from B->DK decays alone a best-fit value of gamma = 72.0 deg is found, and confidence intervals are set gamma in [56.4,86.7] deg at 68% CL, gamma in [42.6,99.6] deg at 95% CL. The best-fit value of gamma found from a combination of results from B->Dpi decays alone, is gamma = 18.9 deg, and the confidence intervals gamma in [7.4,99.2] deg or [167.9,176.4] deg at 68% CL, are set, without constraint at 95% CL. The combination of results from B->DK and B->Dpi decays gives a best-fit value of gamma = 72.6 deg and the confidence intervals gamma in [55.4,82.3] deg at 68% CL, gamma in [40.2,92.7] deg at 95% CL are set. All values are expressed modulo 180 deg, and are obtained taking into account the effect of D0-D0bar mixing.
In this report we summarize the most recent results of measurements of the angle $gamma/phi_3$ of the Unitarity Triangle.
The Belle experiment, running at the KEKB e^+ e^- asymmetric energy collider during the first decade of the century, has recorded 770 fb^-1 of data at the Upsilon(4S) resonance. A combination of recent Belle results obtained with this sample is used to perform a measurement of the CKM angle gamma. We use B^+- -> DK^+- and B^+- -> D^*K^+- decays where the D meson decays into K_S^0pi+pi-, Kpi, KK, pipi, K_S^0 pi^0 and K_S^0 eta final states and D^* decays into Dpi^0 and Dgamma. Belle obtains the most precise gamma measurement to date, gamma = (68^{+15}_{-14}) degree.
The LHC is the new b-hadron factory and will be dominating flavour physics until the start of Belle II, and beyond in many decay modes. While the $B$ factories and Tevatron experiments are still analysing their data, ATLAS, CMS and LHCb are producing interesting new results in CP violation and rare decays, that set strong constraints on models beyond that SM and exhibit some discrepancies with the SM predictions. The LHCb collaboration used the LHC 50 ns ramp-up period of July 2015 to measure the double-differential $J/psi$, $J/psi$-from-$b$-hadron and charm cross-sections at $sqrt{s} = 13$ TeV. Both measurements were performed directly on triggered candidates using a reduced data format that does not require offline processing.
A binned Dalitz plot analysis of $B^pm to D K^pm$ decays, with $D to K_S pi^+pi^-$ and $D to K_S K^+ K^-$, is performed to measure the CP-violating observables $x_{pm}$ and $y_{pm}$, which are sensitive to the Cabibbo-Kobayashi-Maskawa angle $gamma$. The analysis exploits a sample of proton-proton collision data corresponding to 3.0invfb collected by the LHCb experiment. Measurements from CLEO-c of the variation of the strong-interaction phase of the $D$ decay over the Dalitz plot are used as inputs. The values of the parameters are found to be $x_+ = (-7.7 pm 2.4 pm 1.0 pm 0.4)times 10^{-2}$, $x_- = (2.5 pm 2.5 pm 1.0 pm 0.5) times 10^{-2}$, $y_+ = (-2.2 pm 2.5 pm 0.4 pm 1.0)times 10^{-2}$, and $y_- = (7.5 pm 2.9 pm 0.5 pm 1.4) times 10^{-2}$. The first, second, and third uncertainties are the statistical, the experimental systematic, and that associated with the precision of the strong-phase parameters. These are the most precise measurements of these observables and correspond to $gamma = (62^{,+15}_{,-14})^circ$, with a second solution at $gamma to gamma + 180^circ$, and $r_B = 0.080^{+ 0.019}_{-0.021}$, where $r_B$ is the ratio between the suppressed and favoured $B$ decay amplitudes.
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