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Register a new userResonances and $CP$ violation in $B_s^0$ and $overline{B}_s^0 to J/psi K^+K^-$ decays in the mass region above the $phi(1020)$
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The decays of $B_s^0$ and $overline{B}_s^0$ mesons into the $J/psi K^+K^-$ final state are studied in the $K^+K^-$ mass region above the $phi(1020)$ meson in order to determine the resonant substructure and measure the $CP$-violating phase, $phi_s$, the decay width, $Gamma_s$, and the width difference between light and heavy mass eigenstates, $DeltaGamma_s$. A decay-time dependent amplitude analysis is employed. The data sample corresponds to an integrated luminosity of $3{rm fb}^{-1}$ produced in 7 and 8 Tev $pp$ collisions at the LHC, collected by the LHCb experiment. The measurement determines $phi_s = 119pm107pm34 {rm , mrad}$. A combination with previous LHCb measurements using similar decays into the $J/psi pi^+pi^-$ and $J/psiphi(1020)$ final states gives $phi_s=1pm37 {rm ,mrad}$, consistent with the Standard Model prediction.
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The time-dependent $CP$ asymmetry in $B_s^0 to J/psi K^+K^-$ decays is measured using $pp$ collision data, corresponding to an integrated luminosity of $3.0$fb$^{-1}$, collected with the LHCb detector at centre-of-mass energies of $7$ and $8$TeV. In a sample of 96 000 $B_s^0 to J/psi K^+K^-$ decays, the $CP$-violating phase $phi_s$ is measured, as well as the decay widths $Gamma_{L}$ and $Gamma_{H}$ of the light and heavy mass eigenstates of the $B_s^0-bar{B}_s^0$ system. The values obtained are $phi_s = -0.058 pm 0.049 pm 0.006$ rad, $Gamma_s equiv (Gamma_{L}+Gamma_{H})/2 = 0.6603 pm 0.0027 pm 0.0015$ps$^{-1}$, and$DeltaGamma_s equiv Gamma_{L} - Gamma_{H} = 0.0805 pm 0.0091 pm 0.0032$ps$^{-1}$, where the first uncertainty is statistical and the second systematic. These are the most precise single measurements of those quantities to date. A combined analysis with $B_s^{0} to J/psi pi^+pi^-$ decays gives $phi_s = -0.010 pm 0.039 $rad. All measurements are in agreement with the Standard Model predictions. For the first time the phase $phi_s$ is measured independently for each polarisation state of the $K^+K^- $ system and shows no evidence for polarisation dependence.
Measurements are presented of the $CP$ violation observables $S$ and $C$ in the decays of $B^0$ and $overline{B}{}^0$ mesons to the $J/psi K^0_S$ final state. The data sample corresponds to an integrated luminosity of $3.0,text{fb}^{-1}$ collected with the LHCb experiment in proton-proton collisions at center-of-mass energies of $7$ and $8,text{TeV}$. The analysis of the time evolution of $41500$ $B^0$ and $overline{B}{}^0$ decays yields $S = 0.731 pm 0.035 , text{(stat)} pm 0.020 ,text{(syst)}$ and $C = -0.038 pm 0.032 , text{(stat)} pm 0.005,text{(syst)}$. In the Standard Model, $S$ equals $sin(2beta)$ to a good level of precision. The values are consistent with the current world averages and with the Standard Model expectations.
The $CP$ asymmetry in the mixing of $B_s^0$ and $overline{B}{}_s^0$ mesons is measured in proton-proton collision data corresponding to an integrated luminosity of 3.0 fb$^{-1}$, recorded by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Semileptonic $B_s^0$ and $overline{B}{}_s^0$ decays are studied in the inclusive mode $D_s^{mp} mu^{pm} u_{mu} X$ with the $D_s^{mp}$ mesons reconstructed in the $K^+ K^- pi^{mp}$ final state. Correcting the observed charge asymmetry for detection and background effects, the $CP$ asymmetry is found to be $a_{text{sl}}^s = (0.39 pm 0.26 pm 0.20) % $, where the first uncertainty is statistical and the second systematic. This is the most precise measurement of $a_{text{sl}}^s$ to date. It is consistent with the prediction from the Standard Model and will constrain new models of particle physics.
The first measurement of ${C!P}$ asymmetries in the decay ${B_s^0to J/psi overline{K}^{*}(892)^{0}}$ and an updated measurement of its branching fraction and polarisation fractions are presented. The results are obtained using data corresponding to an integrated luminosity of $3.0,fb^{-1}$ of proton-proton collisions recorded with the LHCb detector at centre-of-mass energies of $7$ and $8,mathrm{TeV}$. Together with constraints from ${B^0to J/psi rho^0}$, the results are used to constrain additional contributions due to penguin diagrams in the ${C!P}$-violating phase ${{phi}_{s}}$, measured through ${B_s^0}$ decays to charmonium.
The first observation of the $B_s^0 to overline{D}^{*0} phi$ decay is reported, with a significance of more than seven standard deviations, from an analysis of $pp$ collision data corresponding to an integrated luminosity of 3 fb$^{-1}$, collected with the LHCb detector at centre-of-mass energies of $7$ and $8$ TeV. The branching fraction is measured relative to that of the topologically similar decay $B^0 to overline{D}^0 pi^+pi^-$ and is found to be $mathcal{B}(B_s^0 to overline{D}^{*0} phi) = (3.7 pm 0.5 pm 0.3 pm 0.2) times 10^{-5}$, where the first uncertainty is statistical, the second systematic, and the third from the branching fraction of the $B^0 to overline{D}^0 pi^+pi^-$ decay. The fraction of longitudinal polarisation in this decay is measured to be ${f_{rm L} =(73 pm 15 pm 3)%}$. The most precise determination of the branching fraction for the $B_s^0 to overline{D}^{0} phi$ decay is also obtained, $mathcal{B}(B_s^0 to overline{D}^{0} phi) = (3.0 pm 0.3 pm 0.2 pm 0.2) times 10^{-5}$. An upper limit, $mathcal{B}(B^0 to overline{D}^{0} phi) < 2.0 (2.2) times 10^{-6}$ at $90%$ (95%) confidence level is set. A constraint on the $omega-phi$ mixing angle $delta$ is set at $|delta| < 5.2^circ~ (5.5^circ)$ at $90%$ ($95%$) confidence level.
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