No Arabic abstract
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.
Measurements are presented of the branching fractions of the decays $B_{s}^{0} to D_{s}^{mp} K^{pm}$ and $B^{0} to D_{s}^{-} K^{+}$ relative to the decays $B_{s}^{0} to D_{s}^{-} pi^{+}$ and $B^{0} to D^{-} pi^{+}$, respectively. The data used correspond to an integrated luminosity of 3.0 fb$^{-1}$ of proton-proton collisions. The ratios of branching fractions are $dfrac{mathcal{B}(B_{s}^{0} to D_{s}^{mp} K^{pm})}{mathcal{B}(B_{s}^{0} to D_{s}^{-} pi^{+})} = 0.0752 pm 0.0015 pm 0.0019$ and $dfrac{mathcal{B}(B^{0} to D_{s}^{-} K^{+})}{mathcal{B}(B^{0} to D^{-} pi^{+})} = 0.0129 pm 0.0005 pm 0.0008,$ where the uncertainties are statistical and systematic, respectively.
We study $D_{s}^{+}$ decays to final states involving the $eta$ with a 482$,$pb$^{-1}$ data sample collected at $sqrt{s}$ = 4.009$,$GeV with the mbox{BESIII} detector at the BEPCII collider. We measure the branching fractions $mathcal{B}(D^+_{s}rightarrow etaX)$ = (8.8$pm$1.8$pm$0.5)$%$ and $mathcal{B}(D_{s}^{+}rightarrow etarho^{+})$ = ($5.8pm1.4pm0.4$)$%$ where the first uncertainty is statistical and the second is systematic. In addition, we estimate an upper limit on the non-resonant branching ratio $mathcal{B}(D_{s}^{+}rightarrow etapi^+pi^0)<5.1%$ at the 90$%$ confidence level. Our results are consistent with CLEOs recent measurements and help to resolve the disagreement between the theoretical prediction and CLEOs previous measurement of $mathcal{B}(D_{s}^{+}rightarrow etarho^{+})$.
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 branching fraction measurement of the $B^{0}rightarrow D_{s}^{+}pi^{-}$ decay is presented using proton-proton collision data collected with the LHCb experiment, corresponding to an integrated luminosity of $5.0,$fb$^{-1}$. The branching fraction is found to be ${mathcal{B}(B^{0}rightarrow D_{s}^{+}pi^{-}) = (19.4 pm 1.8pm 1.3 pm 1.2)times 10^{-6}}$, where the first uncertainty is statistical, the second systematic and the third is due to the uncertainty on the $B^0 to D^{-}pi^{+}$, $D_{s}^{+}rightarrow K^{+}K^{-}pi^{+}$ and $D^{-}rightarrow K^{+}pi^{-}pi^{-}$ branching fractions. This is the most precise single measurement of this quantity to date. As this decay proceeds through a single amplitude involving a $b to u$ charged-current transition, the result provides information on non-factorisable strong interaction effects and the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element $V_{ub}$. Additionally, the collision energy dependence of the hadronisation-fraction ratio $f_s/f_d$ is measured through $bar{B}{}_{s}^{0}rightarrow D_{s}^{+}pi^{-}$ and $B^0 to D^{-}pi^{+}$ decays.
We present a measurement of the $CP$-violating weak mixing phase $phi_s$ using the decay $bar{B}^{0}_{s}to D_{s}^{+}D_{s}^{-}$ in a data sample corresponding to $3.0$ fb$^{-1}$ of integrated luminosity collected with the LHCb detector in $pp$ collisions at centre-of-mass energies of 7 and 8 TeV. An analysis of the time evolution of the system, which does not constrain $|lambda|=1$ to allow for the presence of $CP$ violation in decay, yields $phi_s = 0.02 pm 0.17$ (stat) $pm 0.02$ (syst) rad, $|lambda| = 0.91^{+0.18}_{-0.15}$ (stat) $pm0.02$ (syst). This result is consistent with the Standard Model expectation.