Evidence for the decay Bs0→Ds(*)Ds(*) and a measurement of ΔΓsCP/Γs

We search for the semi-inclusive process ${B}_{s}^{0}\ensuremath{\rightarrow}{D}_{s}^{(*)}{D}_{s}^{(*)}$ using $2.8\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ recorded by the D0 detector operating at the Fermilab Tevatron Collider. We observe $26.6\ifmmode\pm\else\textpm\fi{}8.4$ signal events with a significance above background of 3.2 standard deviations yielding a branching ratio of $\mathcal{B}({B}_{s}^{0}\ensuremath{\rightarrow}{D}_{s}^{(*)}{D}_{s}^{(*)})=0.035\ifmmode\pm\else\textpm\fi{}0.010(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}0.011(\mathrm{syst}.)$. Under certain theoretical assumptions, these double-charm final states saturate $CP$-even eigenstates in the ${B}_{s}^{0}$ decays resulting in a width difference of $\ensuremath{\Delta}{\ensuremath{\Gamma}}_{s}^{CP}/{\ensuremath{\Gamma}}_{s}=0.072\ifmmode\pm\else\textpm\fi{}0.021(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}0.022(\mathrm{syst}.)$.