Updated branching fraction measurements of B0( s) → K0Sh+h′ − decays

Abstract The charmless three-body decays B ( s) 0  → K S 0 h + h ′ − (where h (′) = π, K) are analysed using a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 3 fb−1. The branching fractions are measured relative to that of the B 0 → K S 0 π + π − decay, and are determined to be: $$ \begin{array}{l}\frac{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{K}^{\pm }{\pi}^{\mp}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{K}^{+}{\pi}^{-}\right)}=0.123\pm 0.009\left(\mathrm{stat}\right)\pm 0.015\left(\mathrm{syst}\right),\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{K}^{+}{K}^{-}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}=0.549\pm 0.018\left(\mathrm{stat}\right)\pm 0.033\left(\mathrm{syst}\right),\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({B}_s^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}=0.191\pm 0.027\left(\mathrm{stat}\right)\pm 0.031\left(\mathrm{syst}\right)\pm 0.011\left({f}_s/{f}_d\right),\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({B}_s^0\to {K}_{\mathrm{S}}^0{K}^{\pm }{\pi}^{\mp}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}=1.70\pm 0.07\left(\mathrm{stat}\right)\pm 0.11\left(\mathrm{syst}\right)\pm 0.10\left({f}_s/{f}_d\right),\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({B}_s^0\to {K}_{\mathrm{S}}^0{K}^{+}{K}^{-}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}\in \left[0.008-0.051\right]\kern0.5em \mathrm{at}\kern0.5em 90\%\kern0.5em \mathrm{confidence}\kern0.5em \mathrm{level},\hfill \end{array} $$ ℬ B 0 → K S 0 K ± π ∓ ℬ B 0 → K S 0 K + π − = 0.123 ± 0.009 stat ± 0.015 syst , ℬ B 0 → K S 0 K + K − ℬ B 0 → K S 0 π + π − = 0.549 ± 0.018 stat ± 0.033 syst , ℬ B s 0 → K S 0 π + π − ℬ B 0 → K S 0 π + π − = 0.191 ± 0.027 stat ± 0.031 syst ± 0.011 f s / f d , ℬ B s 0 → K S 0 K ± π ∓ ℬ B 0 → K S 0 π + π − = 1.70 ± 0.07 stat ± 0.11 syst ± 0.10 f s / f d , ℬ B s 0 → K S 0 K + K − ℬ B 0 → K S 0 π + π − ∈ 0.008 − 0.051 at 90 % confidence level , where f s /f d represents the ratio of hadronisation fractions of the B s 0 and B 0 mesons.