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Register a new userCP violation in b->c anti-c d decays at Belle
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T. Aushev
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We report a measurement of the CP violation parameters in b->c anti-c d decays. Mixing-induced CP violation involving this transition is studied using a sample of B0->J/psi pi0, D*+D*- and D*+-D-+ decays with a data set accumulated at the Upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. CP violation parameters are extracted from a fit to the distributions of time intervals between two B0 meson decay vertexes.
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The $CP$ violation observables $S$ and $C$ in the decay channel $B^0 !rightarrow D^+ D^-$ are determined from a sample of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 3 fb$^{-1}$. The observable $S$ describes $CP$ violation in the interference between mixing and the decay amplitude, and $C$ parametrizes direct $CP$ violation in the decay. The following values are obtained from a flavor-tagged, decay-time-dependent analysis: begin{align*} S &= -0.54 , ^{+0.17}_{-0.16} , text{(stat)} pm 0.05 , text{(syst)},, ewline C &= phantom{-}0.26 , ^{+0.18}_{-0.17} , text{(stat)} pm 0.02 , text{(syst)},. end{align*} These values provide evidence for $CP$ violation at a significance level of 4.0 standard deviations. The phase shift due to higher-order Standard Model corrections is constrained to a small value of begin{align*} Deltaphi = -0.16,^{+0.19}_{-0.21},text{rad},. end{align*}
I report recent measurements in b-hadron decays reconstructed in the full data set of sqrt{s} = 1.96 TeV proton-antiproton collisions collected by the CDF experiment at the Tevatron. These include the final CDF results on: measurements of CP asymmetries in two-body charmless decays of the Bd, Bs, and Lambda^0_b hadrons; bounds on the Bs mixing phase and on the decay width difference of Bs mass eigenstates; and updated measurements of branching ratios of Bs->Jpsi Phi and Bs->Ds(*)Ds(*) decays. All measurements are among the most precise from a single experiment and in agreement with the standard model predictions.
The decay-time-dependent $CP$ asymmetry in $B^0 to D^{*pm}D^{mp}$ decays is measured using a data set corresponding to an integrated luminosity of $9$fb$^{-1}$ recorded by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The $CP$ parameters are measured as $ S_{D^*D} = -0.861 pm 0.077,text{(stat)} pm 0.019 ,text{(syst)},, $ $ Delta S_{D^*D} = 0.019 pm 0.075 ,text{(stat)} pm 0.012 ,text{(syst)} ,, $ $ C_{D^*D} = -0.059 pm 0.092 ,text{(stat)} pm 0.020 ,text{(syst)} ,, $ $ Delta C_{D^*D} = -0.031 pm 0.092 ,text{(stat)} pm 0.016 ,text{(syst)} ,, $ $ {cal A}_{D^*D} = 0.008 pm 0.014 ,text{(stat)} pm 0.006 ,text{(syst)},. $ The analysis provides the most precise single measurement of $CP$ violation in this decay channel to date. All parameters are consistent with their current world average values.
We present a summary of recent studies on $CP$ violation with the Belle experiment using the final data sample of $772 times 10^{6}$ Bbar{B} pairs produced at the Ypsilon(4S) resonance at the KEK asymmetric e^+ e^- collider. We discuss preliminary measurements of the branching fraction, the polarization and the $CP$ asymmetries of the decay $B^0 rightarrow rho^{+} rho^{-}$ and an updated constraint on the CKM angle $phi_2$ from the $Btorhorho$ system. Being also related to $phi_2$, we present a preliminary measurement of the branching fraction of $B^0rightarrow pi^0pi^0$ decays. Last, a preliminary model independent dalitz plot analysis of the decay $B^0 rightarrow D^0[K_S^0pi^+pi^-]K^{*0}$ is presented and its sensitivity to the CKM angle $phi_3$ is discussed.
The BaBar detector and SLAC PEP-II asymmetric e+e- collider tuned to the Y(4s) resonance has collected around 23M B0 anti-B0 pairs in year 2000. The total data sample for run 1 is 20.7fb-1, using this data we present the study of sin2beta, with samples of B0 --> J/Psi KOS, B0 --> psi(2S) K0S and B0 --> J/Psi KOL decays. The measured value is sin2beta 0.34+/-0.20 (stat) +/- 0.05 (syst),. In addition, we present preliminary measurements of charged and neutral B meson lifetimes and B0-anti B0 oscillation frequency.
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