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Register a new userObservations of $B^0_s rightarrowpsi(2S)eta$ and $B^0_{(s)}rightarrowpsi(2S)pi^+pi^-$ decays
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First observations of the $B^0_s rightarrow psi(2S) eta$, $B^0 rightarrow psi(2S) pi^+ pi^-$ and $B^0_s rightarrow psi(2S) pi^+ pi^-$ decays are made using a dataset corresponding to an integrated luminosity of 1.0~$fb^{-1}$ collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of $sqrt{s}=7$ TeV. The ratios of the branching fractions of each of the $psi(2S)$ modes with respect to the corresponding $J/psi$ decays are [ frac{mathcal{B}(B^0_s rightarrow psi(2S) eta) }{mathcal{B}(B^0_s rightarrow J/psi eta)} =0.83pm0.14,(stat)pm0.12,(syst)pm0.02,(mathcalB}), ] [ frac{mathcal{B}(B^0 rightarrow psi(2S) pi^+ pi^-)}{mathcal{B}(B^0 rightarrow J/psi pi^+ pi^-)} =0.56pm0.07,(stat)pm0.05,(syst)pm0.01,(mathcal{B}), ] [ frac{mathcal{B}(B^0_s rightarrow psi(2S) pi^+ pi^-)}{mathcal{B}(B^0_s rightarrow J/psi pi^+ pi^-)} =0.34pm0.04,(stat)pm0.03,(syst)pm0.01,(mathcal{B}), ] where the third uncertainty corresponds to the uncertainties of the dilepton branching fractions of the $J/psi$ and $psi(2S)$ meson decays.
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The decays $B^+rightarrow J/psi 3pi^+ 2pi^-$ and $B^+rightarrow psi(2S) pi^+pi^+pi^-$ are observed for the first time using a data sample corresponding to an integrated luminosity of $3.0fb^{-1}$, collected by the LHCb experiment in proton-proton collisions at the centre-of-mass energies of 7 and 8 TeV. The branching fractions relative to that of $B^+ rightarrow psi(2S)K^+$ are measured to be begin{eqnarray*} frac {mathcal{B}left(B^+rightarrow J/psi 3pi^+ 2pi^- right)} {mathcal{B}left(B^+ rightarrow psi(2S)K^+ right)} & = & left(1.88pm0.17pm0.09right)times10^{-2}, frac {mathcal{B}left(B^+rightarrow psi(2S) pi^+pi^+pi^- right)} {mathcal{B}left(B^+ rightarrow psi(2S)K^+ right)} & = & left(3.04pm0.50pm0.26right)times10^{-2}, end{eqnarray*} where the first uncertainties are statistical and the second are systematic.
Evidence for the decay mode $X(3872)rightarrowpsi(2S)gamma$ in $B^+rightarrow X(3872)K^+$ decays is found with a significance of 4.4 standard deviations. The analysis is based on a data sample of proton-proton collisions, corresponding to an integrated luminosity of 3fb$^{-1}$ collected with the LHCb detector, at centre-of-mass energies of 7 and 8TeV. The ratio of the branching fraction of the $X(3872)topsi(2S)gamma$ decay to that of the $X(3872)rightarrow J/psi gamma$ decay is measured to be $$ frac{Br(X(3872)rightarrowpsi(2S)gamma)}{Br(X(3872)rightarrow J/psigamma)} = 2.46pm0.64pm0.29, %pm0.06,$$ where the first uncertainty is statistical and the second is systematic. The measured value agrees with expectations for a pure charmonium interpretation of the $X(3872)$ state and a mixture of charmonium and molecular interpretations. However, it does not support a pure $Dbar{D}^{*}$ molecular interpretation of the $X(3872)$state.
A study of B+ to J/psi pi+ and B+ to psi(2S) pi+ decays is performed with data corresponding to 0.37 fb-1 of proton-proton collisions at sqrt(s)=7 TeV. Their branching fractions are found to be B(B+ to J/psi pi+) = (3.88 +- 0.11 +- 0.15) x 10^{-5} and B(B+ to psi(2S) pi+) = (2.52 +- 0.26 +- 0.15) x 10^{-5}, where the first uncertainty is related to the statistical size of the sample and the second quantifies systematic effects. The measured CP asymmetries in these modes are ACP(J/psi pi) = 0.005 +- 0.027 +- 0.011 and ACP(psi(2S) pi) = 0.048 +- 0.090 +- 0.011 with no evidence of direct CP violation seen.
The first observation of the decays $bar{B}^0_{s}to D_s^+K^-pi^+pi^-$ and $bar{B}^0to D_s^+K^-pi^+pi^-$ are reported using an integrated luminosity of 1.0 fb$^{-1}$ recorded by the LHCb experiment. The branching fractions, normalized with respect to $bar{B}^0_{s}to D_s^+pi^-pi^+pi^-$ and $bar{B}^0_{s}to D_s^+K^-pi^+pi^-$, respectively, are measured to be {br(bar{B}^0_{s}to D_s^+K^-pi^+pi^-)overbr(bar{B}^0_{s}to D_s^+pi^-pi^+pi^-)} &= (5.2pm0.5pm0.3)times10^{-2}, {br(bar{B}^0to D_s^+K^-pi^+pi^-)overbr(bar{B}^0_{s}to D_s^+K^-^pi^+pi^-)} &= 0.54pm0.07pm0.07, where the first uncertainty is statistical and the second is systematic. The $bar{B}^0_{s}to D_s^+K^-pi^+pi^-$ decay is of particular interest as it can be used to measure the weak phase $gamma$. First observation of the $bar{B}^0_sto D_{s1}(2536)^+pi^-, D_{s1}^+to D_s^+pi^-pi^+$ decay is also presented, and its branching fraction relative to $bar{B}^0_{s}to D_s^+pi^-pi^+pi^-$ is found to be {br(bar{B}^0_sto D_{s1}(2536)^+pi^-, D_{s1}^+to D_s^+pi^-pi^+)overbr(bar{B}^0_{s}to D_s^+pi^-pi^+pi^-)} &= (4.0pm1.0pm0.4)times10^{-3}.
A search for previously unobserved decays of beauty baryons to the final states $K^0_{rmscriptscriptstyle S} p pi^{-}$ and $K^0_{rmscriptscriptstyle S}p K^{-}$ is reported. The analysis is based on a data sample corresponding to an integrated luminosity of $1.0,$fb$^{-1}$ of $pp$ collisions. The $Lambda^0_{b} rightarrow overline{kern -0.2em K}^0_{rmscriptscriptstyle S}p pi^{-}$ decay is observed with a significance of $8.6,sigma$, with branching fraction begin{eqnarray*} {cal{B}}(Lambda^0_{b} rightarrow overline{kern -0.2em K}^0 p pi^{-}) & = & left(1.26 pm 0.19 pm 0.09 pm 0.34 pm 0.05 right) times 10^{-5} ,, end{eqnarray*} where the uncertainties are statistical, systematic, from the ratio of fragmentation fractions $f_{Lambda}/f_{d}$, and from the branching fraction of the $B^0 rightarrow K^0_{rmscriptscriptstyle S}pi^{+}pi^{-}$ normalisation channel, respectively. A first measurement is made of the $CP$ asymmetry, giving begin{eqnarray*} A_{C/!P} (Lambda^0_{b} rightarrow overline{kern -0.2em K}^0 p pi^{-}) & = & 0.22 pm 0.13mathrm{,(stat)} pm 0.03mathrm{,(syst)} , . end{eqnarray*} No significant signals are seen for $Lambda^0_{b} rightarrow K^0_{rmscriptscriptstyle S}p K^{-}$ decays, $Xi^{0}_{b}$ decays to both the $K^0_{rmscriptscriptstyle S}p pi^{-}$ and $K^0_{rmscriptscriptstyle S}p K^{-}$ final states, and the $Lambda^0_{b} rightarrow D^{-}_{s} (rightarrow K^0_{rmscriptscriptstyle S} K^{-}) p$ decay, and upper limits on their branching fractions are reported.
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