부산대학교 도서관

Abstract The ratios of the branching fractions of the decays Λ c + → pπ − π +, Λ c + → pK − K +, and Λ c + → pπ − K + with respect to the Cabibbo-favoured Λ c + → pK − π + 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: ℬ Λ c + → p π − π + ℬ Λ c + → p K − π + = 7.44 ± 0.08 ± 0.18 % , ℬ Λ c + → p K − K + ℬ Λ c + → p K − π + = 1.70 ± 0.03 ± 0.03 % ℬ Λ c + → p π − K + ℬ Λ c + → p K − π + = 0.165 ± 0.015 ± 0.005 % , $$ \begin{array}{l}\frac{\mathrm{\mathcal{B}}\left({\varLambda}_c^{+}\to p{\pi}^{-}{\pi}^{+}\right)}{\mathrm{\mathcal{B}}\left({\varLambda}_c^{+}\to p{K}^{-}{\pi}^{+}\right)}=\left(7.44\pm 0.08\pm 0.18\right)\%,\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({\varLambda}_c^{+}\to p{K}^{-}{K}^{+}\right)}{\mathrm{\mathcal{B}}\left({\varLambda}_c^{+}\to p{K}^{-}{\pi}^{+}\right)}=\left(1.70\pm 0.03\pm 0.03\right)\%\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({\varLambda}_c^{+}\to p{\pi}^{-}{K}^{+}\right)}{\mathrm{\mathcal{B}}\left({\varLambda}_c^{+}\to p{K}^{-}{\pi}^{+}\right)}=\left(0.165\pm 0.015\pm 0.005\right)\%,\hfill \end{array} $$ 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 ℬ Λ c + → p K − π + $$ \mathrm{\mathcal{B}}\left({\varLambda}_c^{+}\to p{K}^{-}{\pi}^{+}\right) $$ , the corresponding branching fractions are ℬ Λ c + → p π − π + = 4.72 ± 0.05 ± 0.11 ± 0.25 × 10 − 3 , ℬ Λ c + → p K − K + = 1.08 ± 0.02 ± 0.02 ± 0.06 × 10 − 3 , ℬ Λ c + → p π − K + = 1.04 ± 0.09 ± 0.03 ± 0.05 × 10 − 4 , $$ \begin{array}{l}\mathrm{\mathcal{B}}\left({\varLambda}_c^{+}\to p{\pi}^{-}{\pi}^{+}\right)=\left(4.72\pm 0.05\pm 0.11\pm 0.25\right)\times {10}^{-3},\hfill \\ {}\mathrm{\mathcal{B}}\left({\varLambda}_c^{+}\to p{K}^{-}{K}^{+}\right)=\left(1.08\pm 0.02\pm 0.02\pm 0.06\right)\times {10}^{-3},\hfill \\ {}\mathrm{\mathcal{B}}\left({\varLambda}_c^{+}\to p{\pi}^{-}{K}^{+}\right)=\left(1.04\pm 0.09\pm 0.03\pm 0.05\right)\times {10}^{-4},\hfill \end{array} $$ where the final uncertainty is due to ℬ Λ c + → p K − π + $$ \mathrm{\mathcal{B}}\left({\varLambda}_c^{+}\to p{K}^{-}{\pi}^{+}\right) $$ .