No Arabic abstract
We search for the decay $B_{s}^{0}rightarrowgammagamma$ and measure the branching fraction for $B_{s}^{0}rightarrowphigamma$ using 121.4~$textrm{fb}^{-1}$ of data collected at the $Upsilon(mathrm{5}S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}e^{-}$ collider. The $B_{s}^{0}rightarrowphigamma$ branching fraction is measured to be $(3.6 pm 0.5 (mathrm{stat.}) pm 0.3 (mathrm{syst.}) pm 0.6 (f_{s})) times 10^{-5}$, where $f_{s}$ is the fraction of $B_{s}^{(*)}bar{B}_{s}^{(*)}$ in $bbar{b}$ events. Our result is in good agreement with the theoretical predictions as well as with a recent measurement from LHCb. We observe no statistically significant signal for the decay $B_{s}^{0}rightarrowgammagamma$ and set a $90%$ confidence-level upper limit on its branching fraction at $ 3.1 times 10^{-6}$. This constitutes a significant improvement over the previous result.
The branching fraction of the decay $B_{s}^{0} rightarrow D_{s}^{(*)+}D_{s}^{(*)-}$ is measured using $pp$ collision data corresponding to an integrated luminosity of $1.0fb^{-1}$, collected using the LHCb detector at a centre-of-mass energy of $7$TeV. It is found to be begin{align*} {mathcal{B}}(B_{s}^{0}rightarrow~D_{s}^{(*)+}D_{s}^{(*)-}) = (3.05 pm 0.10 pm 0.20 pm 0.34)%, end{align*} where the uncertainties are statistical, systematic, and due to the normalisation channel, respectively. The branching fractions of the individual decays corresponding to the presence of one or two $D^{*pm}_{s}$ are also measured. The individual branching fractions are found to be begin{align*} {mathcal{B}}(B_{s}^{0}rightarrow~D_{s}^{*pm}D_{s}^{mp}) = (1.35 pm 0.06 pm 0.09 pm 0.15)%, ewline{mathcal{B}}(B_{s}^{0}rightarrow~D_{s}^{*+}D_{s}^{*-}) = (1.27 pm 0.08 pm 0.10 pm 0.14)%. end{align*} All three results are the most precise determinations to date.
A search for charmless three-body decays of $B^0$ and $B_{s}^0$ mesons with a $K_{rm S}^0$ meson in the final state is performed using the $pp$ collision data, corresponding to an integrated luminosity of $1.0,mbox{fb}^{-1}$, collected at a centre-of-mass energy of $7mathrm{,Tekern -0.1em V}$ recorded by the LHCb experiment. Branching fractions of the $B_{(s)}^0 to K_{rm S}^0 h^{+} h^{prime -}$ decay modes ($h^{(prime)} = pi, K$), relative to the well measured $B^0 to K_{rm S}^0 pi^{+} pi^{-}$ decay, are obtained. First observation of the decay modes $B_s^0 to K_{rm S}^0 K^{pm} pi^{mp}$ and $B_s^0 to K_{rm S}^0 pi^{+} pi^{-}$ and confirmation of the decay $B^0 to K_{rm S}^0 K^{pm} pi^{mp}$ are reported. The following relative branching fraction measurements or limits are obtained begin{eqnarray*} onumber frac{{cal B}(B^0 to K_{rm S}^0 K^{pm} pi^{mp})}{{cal B}(B^0 to K_{rm S}^0 pi^{+} pi^{-})} &=& 0.128 pm 0.017 , ({rm stat.}) pm 0.009 , ({rm syst.}) ,, onumber frac{{cal B}(B^0 to K_{rm S}^0 K^{+} K^{-} )}{{cal B}(B^0 to K_{rm S}^0 pi^{+} pi^{-})} &=& 0.385 pm 0.031 , ({rm stat.}) pm 0.023 , ({rm syst.}) ,, onumber frac{{cal B}(B_s^0 to K_{rm S}^0 pi^{+} pi^{-} )}{{cal B}(B^0 to K_{rm S}^0 pi^{+} pi^{-})} &=& 0.29phantom{0} pm 0.06phantom{0} , ({rm stat.}) pm 0.03phantom{0} , ({rm syst.}) pm 0.02 , (f_s/f_d) ,, onumber frac{{cal B}(B_s^0 to K_{rm S}^0 K^{pm} pi^{mp})}{{cal B}(B^0 to K_{rm S}^0 pi^{+} pi^{-})} &=& 1.48phantom{0} pm 0.12phantom{0} , ({rm stat.}) pm 0.08phantom{0} , ({rm syst.}) pm 0.12 , (f_s/f_d) ,, onumber frac{{cal B}(B_s^0 to K_{rm S}^0 K^{+} K^{-} )}{{cal B}(B^0 to K_{rm S}^0 pi^{+} pi^{-})} &in& [0.004;0.068] ; {rm at ;; 90% ; CL} ,. end{eqnarray*}
Branching fractions of the decays $H_bto H_cpi^-pi^+pi^-$ relative to $H_bto H_cpi^-$ are presented, where $H_b$ ($H_c$) represents B^0-bar($D^+$), $B^-$ ($D^0$), B_s^0-bar ($D_s^+$) and $Lambda_b^0$ ($Lambda_c^+$). The measurements are performed with the LHCb detector using 35${rm pb^{-1}}$ of data collected at $sqrt{s}=7$ TeV. The ratios of branching fractions are measured to be B(B^0-bar -> D^+pi^-pi^+pi^-)/ B(B^0-bar -> D^+pi^-) = 2.38pm0.11pm0.21 B(B^- -> D^0pi^-pi^+pi^-) / B(B^- -> D^0pi^-) = 1.27pm0.06pm0.11 B(B_s^0-bar -> D_s^+pi^-pi^+pi^-) / B(B_s^0-bar -> D_s^+pi^-) = 2.01pm0.37pm0.20 B(Lambda_b^0->Lambda_c^+pi^-pi^+pi^-) / B(Lambda_b^0 -> Lambda_c^+pi^-) = 1.43pm0.16pm0.13. We also report measurements of partial decay rates of these decays to excited charm hadrons. These results are of comparable or higher precision than existing measurements.
A measurement of the relative branching fraction of $B_{s}^{0} rightarrow J/ps i f_{0}(980), f_{0}(980) rightarrow pi^{+}pi^{-}$ to $B_{s}^{0} rightarrow J/psi phi, p hi rightarrow K^{+}K^{-}$ is presented. The decay mode $B_{s}^{0} rightarrow J/psi f_{0}(980)$ is an interesting mode since it is a CP-odd eigenstate which could be used in CP-violating studies. Using approximat ely 8 $rm{fb}^{-1}$ of data recorded with the D0 detector at the Fermilab Tevatron Collider, a relative branching fraction of 0.210 $pm$ 0.032thinspace(stat) $pm$ 0.036thi nspace(syst) is found.
A study of $B^{0}_{s} to eta_{c} phi$ and $B^{0}_{s} to eta_{c} pi^{+}pi^{-}$ decays is performed using $pp$ collision data corresponding to an integrated luminosity of 3.0$,rm fb^{-1}$, collected with the LHCb detector in Run~1 of the LHC. The observation of the decay $B^{0}_{s} to eta_{c} phi$ is reported, where the $eta_{c}$ meson is reconstructed in the $pbar p$, $K^+K^-pi^+pi^-$, $pi^+pi^-pi^+pi^-$ and $K^+K^-K^+K^-$ decay modes and the $phi(1020)$ in the $K^+ K^-$ decay mode. The decay $B^{0}_{s} to J/psi phi$ is used as a normalisation channel. Evidence is also reported for the decay $B^{0}_{s} to eta_{c} pi^{+}pi^{-}$, where the $eta_{c}$ meson is reconstructed in the $pbar p$ decay mode, using the decay $B^{0}_{s} to J/psi pi^+ pi^-$ as a normalisation channel. The measured branching fractions are begin{eqnarray*} {mathcal B (B^{0}_{s} to eta_{c} phi)} &=& left(5.01 pm 0.53 pm 0.27 pm 0.63 right) times 10^{-4} ,, onumber {mathcal B (B^{0}_{s} to eta_{c} pi^+ pi^-)} &=& left(1.76 pm 0.59 pm 0.12 pm 0.29 right) times 10^{-4} ,, end{eqnarray*} where in each case the first uncertainty is statistical, the second systematic and the third uncertainty is due to the limited knowledge of the external branching fractions.