Measurement of the branching fraciton of the neutral B(s) meson decaying to D(s)-D(s) mesons and the lifetime difference in the neutral B(s) meson system

We search for the semi-inclusive process B0s→D* sD* s using 2.8 fb-1 of pp¯ collisions at s = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. Under certain theoretical assumptions, these double-charm final states saturate CP-even eigenstates in the B0s decays, allowing the lifetime difference of the B0s system to be related to the branching ratio. We observe 26.6 +/- 8.4 signal events with a significance above background of 3.2 standard deviations. The branching ratio is measured as B&parl0;B0s→D *sD *s&parr0; = 0.035 +/- 0.010(stat) +/- 0.011(syst) and, in the Standard Model, the width difference is derived as DGCPs/G s = 0.072 +/- 0.021(stat) +/- 0.022(syst).