Measurement of the branching fraction of the B0→Ds+π- decay

Abstract

A branching fraction measurement of the B0→Ds+π-$${{B} ^0} {\rightarrow }{{D} ^+{s}} {{\pi } ^-} $$ decay is presented using proton–proton collision data collected with the LHCb experiment, corresponding to an integrated luminosity of 5.0fb-1$$5.0,\text {fb} ^{-1} $$. The branching fraction is found to be B(B0→Ds+π-)=(19.4±$${\mathcal {B}} ({{B} ^0} {\rightarrow }{{D} ^+{s}} {{\pi } ^-} ) =(19.4 \pm $$1.8±1.3±1.2)×10-6$$1.8\pm 1.3 \pm 1.2)\times 10^{-6}$$, where the first uncertainty is statistical, the second systematic and the third is due to the uncertainty on the B0→D-π+$${{B} ^0} {\rightarrow }{{D} ^-} {{\pi } ^+} $$, Ds+→K+K-π+$${{D} ^+{s}} {\rightarrow }{{K} ^+} {{K} ^-} {{\pi } ^+} $$ and D-→K+π-π-$${{D} ^-} {\rightarrow }{{K} ^+} {{\pi } ^-} {{\pi } ^-} $$ 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→u$$b{\rightarrow }u$$ charged-current transition, the result provides information on non-factorisable strong interaction effects and the magnitude of the Cabibbo–Kobayashi–Maskawa matrix element Vub$$V{ub}$$. Additionally, the collision energy dependence of the hadronisation-fraction ratio fs/fd$$f_s/f_d$$ is measured through B¯s0→Ds+π-$${{\overline{B}} {}^0_{s}} {\rightarrow }{{D} ^+_{s}} {{\pi } ^-} $$ and B0→D-π+$${{B} ^0} {\rightarrow }{{D} ^-} {{\pi } ^+} $$ decays.