A search for the decays $B^0_{s}\rightarrow \mu^+ \mu^- \mu^+ \mu^-$ and $B^0 \rightarrow \mu^+ \mu^- \mu^+ \mu^-$ is performed using data, corresponding to an integrated luminosity of ...1.0\ensuremath{\{\,fb}^{-1}}\xspace, collected with the LHCb detector in 2011. The number of candidates observed is consistent with the expected background and, assuming phase-space models of the decays, limits on the branching fractions are set: \{${\ensuremath{\cal B}\xspace}(B^0_{s}\rightarrow \mu^+ \mu^- \mu^+ \mu^-) < 1.6 \ (1.2) \times 10^{-8}$} and \{${\ensuremath{\cal B}\xspace}(B^0 \rightarrow \mu^+ \mu^- \mu^+ \mu^-)< 6.6 \ (5.3) \times 10^{-9}$} at 95\,% (90\,%) confidence level. In addition, limits are set in the context of a supersymmetric model which allows for the $B^0_{(s)}$ meson to decay into a scalar ($S$) and pseudoscalar particle ($P$), where $S$ and $P$ have masses of 2.5 GeV and 214.3 MeV, respectively, both resonances decay into $\mu^+\mu^-$. The branching fraction limits for these decays are \{${\ensuremath{\cal B}\xspace}(\ensuremath{B^0_{s}\rightarrow SP}\xspace) < 1.6 \ (1.2) \times 10^{-8}$} and \{${\ensuremath{\cal B}\xspace}(\ensuremath{B^0\rightarrow SP}\xspace)< 6.3 \ (5.1) \times 10^{-9}$} at 95% (90%) confidence level.
The decay $B_c^+\to J/\psi K^+$ is observed for the first time using a data sample, corresponding to an integrated luminosity of 1.0 ${\,fb}^{-1}$, collected by the LHCb experiment in $pp$ collisions ...at a centre-of-mass energy of $7\mathrm{\,Te\kern -0.1em V}$. A yield of $46\pm12$ events is reported, with a significance of 5.0 standard deviations. The ratio of the branching fraction of $B_c^+\to J/\psi K^+$ to that of $B_c^+\to J/\psi\pi^+$ is measured to be $0.069\pm0.019\pm0.005$, where the first uncertainty is statistical and the second is systematic.
A first observation of the decay $B_s^0 \rightarrow \phi \bar{K}^{*0}$ is reported from an analysis based on a data sample, corresponding to an integrated luminosity of 1.0 fb$^{-1}$ of $pp$ ...collisions at sqrt(s) = 7 TeV, collected with the LHCb detector. A yield of $30 \pm 6$ $B_s^0 \rightarrow (KK)(K\pi)$ candidates is found in the mass windows $1012.5 < M(KK) < 1026.5 MeV/c^2$ and $746 < M(K\pi)< 1046 MeV/c^2$, corresponding to a signal significance of 6.1 standard deviations. The candidates are found to be dominated by $B_s^0 \rightarrow \phi \bar{K}^{*0}$ decays, and the branching fraction is measured to be $BF(B_s^0 \rightarrow \phi \bar{K}^{*0}) = (1.10 \pm 0.24 (stat) \pm 0.14 (syst) \pm 0.08 (f_d/f_s)) \times 10^{-6}$, where the uncertainties are statistical, systematic and from the ratio of fragmentation fractions $f_d/f_s$ which accounts for the different production rate of $B^0$ and $B_s^0$ mesons. The fraction of longitudinal polarization in $B_s^0 \rightarrow \phi \bar{K}^{*0}$ decays is found to be $f_0 = 0.51 \pm 0.15 (stat) \pm 0.07 (syst)$.
An analysis of $B^{\pm}\to DK^{\pm}$ and $B^{\pm}\to D\pi^{\pm}$ decays is presented where the $D$ meson is reconstructed in the four-body final state $K^{\pm}\pi^{\mp} \pi^+ \pi^-$. Using LHCb data ...corresponding to an integrated luminosity of $1.0{\rm \,fb}^{-1}$, first observations are made of the suppressed ADS modes $B^{\pm}\to \pi^{\pm} K^{\mp}\pi^+\pi^-_D K^{\pm}$ and $B^{\pm}\to \pi^{\pm} K^{\mp} \pi^+\pi^- _D\pi^{\pm}$ with a significance of $5.1\sigma$ and greater than $10\sigma$, respectively. Measurements of CP asymmetries and CP-conserving ratios of partial widths from this family of decays are also performed. The magnitude of the ratio between the suppressed and favoured $B^{\pm}\to DK^{\pm}$ amplitudes is determined to be $r^K_B = 0.097 \pm{0.011}$.
The determination of the differential branching fraction and the first angular analysis of the decay $B_s^0\to\phi\mu^{+}\mu^{-}$ are presented using data, corresponding to an integrated luminosity ...of $1.0\,{\rm fb}^{-1}$, collected by the LHCb experiment at $\sqrt{s}=7\,{\rm TeV}$. The differential branching fraction is determined in bins of $q^{2}$, the invariant dimuon mass squared. Integration over the full $q^{2}$ range yields a total branching fraction of ${\cal B}(B_s^0\to\phi\mu^{+}\mu^{-}) = (7.07\,^{+0.64}_{-0.59}\pm 0.17 \pm 0.71)\times 10^{-7}$, where the first uncertainty is statistical, the second systematic, and the third originates from the branching fraction of the normalisation channel. An angular analysis is performed to determine the angular observables $F_{\rm L}$, $S_3$, $A_6$, and $A_9$. The observables are consistent with Standard Model expectations.
A measurement of the CP asymmetry in B(0)→K(*0)μ(+)μ(-) decays is presented, based on 1.0 fb(-1) of pp collision data recorded by the LHCb experiment during 2011. The measurement is performed in six ...bins of invariant mass squared of the μ(+)μ(-) pair, excluding the J/ψ and ψ(2S) resonance regions. Production and detection asymmetries are removed using the B(0)→J/ψK(*0) decay as a control mode. The integrated CP asymmetry is found to be -0.072±0.040(stat)±0.005(syst), consistent with the standard model.
The production of J/psi and Upsilon mesons in pp collisions at sqrt(s) = 8 TeV is studied with the LHCb detector. The J/psi and Upsilon mesons are reconstructed in the mu+mu- decay mode and the ...signal yields are determined with a fit to the mu+mu- invariant mass distributions. The analysis is performed in the rapidity range 2.0
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