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Register a new userMeasurements of the branching fractions of $Lambda_{c}^{+} rightarrow p pi^{-} pi^{+}$, $Lambda_{c}^{+} rightarrow p K^{-} K^{+}$, and $Lambda_{c}^{+} rightarrow p pi^{-} K^{+}$
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The ratios of the branching fractions of the decays $Lambda_{c}^{+} rightarrow p pi^{-} pi^{+}$, $Lambda_{c}^{+} rightarrow p K^{-} K^{+}$, and $Lambda_{c}^{+} rightarrow p pi^{-} K^{+}$ with respect to the Cabibbo-favoured $Lambda_{c}^{+} rightarrow p K^{-} pi^{+}$ decay are measured using proton-proton collision data collected with the LHCb experiment at a 7 TeV centre-of-mass energy and corresponding to an integrated luminosity of 1.0 fb$^{-1}$: begin{align*} frac{mathcal{B}(Lambda_{c}^{+} rightarrow p pi^{-} pi^{+})}{mathcal{B}(Lambda_{c}^{+} rightarrow p K^{-} pi^{+})} & = (7.44 pm 0.08 pm 0.18),%, frac{mathcal{B}(Lambda_{c}^{+} rightarrow p K^{-} K^{+})}{mathcal{B}(Lambda_{c}^{+} rightarrow p K^{-} pi^{+})} &= (1.70 pm 0.03 pm 0.03),%, frac{mathcal{B}(Lambda_{c}^{+} rightarrow p pi^{-} K^{+})}{mathcal{B}(Lambda_{c}^{+} rightarrow p K^{-} pi^{+})} & = (0.165 pm 0.015 pm 0.005 ),%, end{align*} where the uncertainties are statistical and systematic, respectively. These results are the most precise measurements of these quantities to date. When multiplied by the world-average value for $mathcal{B}(Lambda_{c}^{+} rightarrow p K^{-} pi^{+})$, the corresponding branching fractions are begin{align*} mathcal{B}(Lambda_{c}^{+} rightarrow p pi^{-} pi^{+}) &= (4.72 pm 0.05 pm 0.11 pm 0.25) times 10^{-3}, mathcal{B}(Lambda_{c}^{+} rightarrow p K^{-} K^{+}) &= (1.08 pm 0.02 pm 0.02 pm 0.06) times 10^{-3}, mathcal{B}(Lambda_{c}^{+} rightarrow p pi^{-} K^{+}) &= (1.04 pm 0.09 pm 0.03 pm 0.05) times 10^{-4}, end{align*} where the final uncertainty is due to $mathcal{B}(Lambda_{c}^{+} rightarrow p K^{-} pi^{+})$.
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We investigate the reaction $ pi^- p rightarrow D^- Lambda_{c}^{+} $ within the generalized parton picture. The process is described by a handbag-type mechanism with the charm-quark mass acting as the hard scale. As in the case of preceding work on $bar{p} p rightarrow bar{Lambda}^-_c Lambda_{c}^{+} $ we argue that the process amplitude factorizes into one for the perturbatively calculable partonic subprocess $bar{u} urightarrow bar{c} c$ and hadronic matrix elements that can be parameterized in terms of generalized parton distributions. Modeling the generalized parton distributions by overlaps of (valence-quark) light-cone wave functions for the hadrons involved, we obtain numerical results for unpolarized differential and integrated cross sections as well as spin observables. Our approach works well above the production threshold ($s gtrsim 20 $GeV$^2$) in the forward hemisphere and predicts unpolarized cross sections of the order of nb, a finding that could be of interest in view of plans to measure $ pi^- p rightarrow D^- Lambda_{c}^{+} $ at J-PARC.
We report branching fraction measurements of four decay modes of the $Lambda_{c}^{+}$ baryon, each of which includes an $eta$ meson and a $Lambda$ baryon in the final state, and all of which are measured relative to the $Lambda_{c}^{+} rightarrow p K^{-} pi^{+}$ decay mode. The results are based on a $980~mathrm{fb^{-1}}$ data sample collected by the Belle detector at the KEKB asymmetric-energy $e^{+}e^{-}$ collider. Two decays, $eta Sigma^{0} pi^{+}$ and $Lambda(1670) pi^{+}$, are observed for the first time, while the measurements of the other decay modes, $Lambda_{c}^{+} rightarrow etaLambdapi^{+}$ and $etaSigma(1385)^{+}$, are more precise than those made previously. We obtain $mathcal{B}(Lambda_{c}^{+} rightarrow eta Lambda pi^{+})/mathcal{B}(Lambda_{c}^{+} rightarrow p K^{-} pi^{+})$ = $0.293 pm 0.003 pm 0.014$, $mathcal{B}(Lambda_{c}^{+} rightarrow eta Sigma^{0} pi^{+})/mathcal{B}(Lambda_{c}^{+} rightarrow p K^{-} pi^{+})$ = $0.120 pm 0.006 pm 0.006$, $mathcal{B}(Lambda_{c}^{+} rightarrow Lambda(1670) pi^{+}) times mathcal{B}(Lambda(1670) rightarrow eta Lambda)/mathcal{B}(Lambda_{c}^{+} rightarrow p K^{-} pi^{+})$ = $(5.54 pm 0.29 pm 0.73 ) times 10^{-2}$, and $mathcal{B}(Lambda_{c}^{+} rightarrow eta Sigma(1385)^{+})/mathcal{B}(Lambda_{c}^{+} rightarrow p K^{-} pi^{+})$ = $0.192 pm 0.006 pm 0.016$. The mass and width of the $Lambda(1670)$ are also precisely determined to be $1674.3 pm 0.8 pm 4.9~{rm MeV}/c^{2}$ and $36.1 pm 2.4 pm 4.8~{rm MeV}$, respectively, where the uncertainties are statistical and systematic, respectively.
The branching fractions of the doubly Cabibbo-suppressed decays $D^+rightarrow K^-K^+K^+$, $D^+rightarrow pi^-pi^+K^+$ and $D^+_srightarrowpi^-K^+K^+$ are measured using the decays $D^+rightarrow K^-pi^+pi^+$ and $D^+_srightarrow K^-K^+pi^+$ as normalisation channels. The measurements are performed using proton-proton collision data collected with the LHCb detector at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 2.0 fb$^{-1}$. The results are begin{align} frac {mathcal{B}(D^+rightarrow K^-K^+K^+)} {mathcal{B}(D^+rightarrow K^-pi^+pi^+)}& = (6.541 pm 0.025 pm 0.042) times 10^{-4}, onumber frac {mathcal{B}(D^+rightarrow pi^-pi^+K^+)} {mathcal{B}(D^+rightarrow K^-pi^+pi^+)}& = (5.231 pm 0.009 pm 0.023) times 10^{-3}, onumber frac {mathcal{B}(D^+_srightarrowpi^-K^+K^+)} {mathcal{B}(D^+_srightarrow K^-K^+pi^+)}& = (2.372 pm 0.024 pm 0.025) times 10^{-3}, onumber end{align} where the uncertainties are statistical and systematic, respectively. These are the most precise measurements up to date.
Using data samples collected with the BESIII detector at center-of-mass energies $sqrt{s} = 4.23, 4.26, 4.36,$ and $4.42$~rm{GeV}, we measure the branching fractions of $eta_cto K^+K^-pi^0$, $K^0_S K^{pm}pi^{mp}$, $2(pi^+pi^-pi^0)$, and $p bar{p}$, via the process $e^+e^-topi^+pi^-h_c$, $h_ctogammaeta_c$. The corresponding results are $(1.15pm0.12pm0.10)%$, $(2.60pm0.21pm0.20)%$, $(15.2pm1.8pm1.7)%$, and $(0.120pm0.026pm0.015)%$, respectively. Here the first uncertainties are statistical, and the second ones systematic. Additionally, the charged track multiplicity of $eta_c$ decays is measured for the first time.
A search is made for the highly-suppressed B meson decays $B^{+}rightarrow K^{+}K^{+}pi^{-}$ and $B^{+}rightarrow pi^{+}pi^{+}K^{-}$ using a data sample corresponding to an integrated luminosity of 3.0 $fb^{-1}$ collected by the LHCb experiment in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. No evidence is found for the decays, and upper limits at 90% confidence level are determined to be $mathcal{B}(B^{+}rightarrow K^{+}K^{+}pi^{-}) < 1.1times 10^{-8}$ and $mathcal{B}(B^{+}rightarrow pi^{+}pi^{+}K^{-}) < 4.6times 10^{-8}$.
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