Time Dependent B0s - B0s-bar Mixing Using Inclusive and Semileptonic B Decays at SLD

TL;DR

This paper reports a preliminary 95% confidence level exclusion on the B0s - B0s-bar mixing oscillation frequency using inclusive and semileptonic B decay analyses from SLD data, constraining the possible values of the oscillation parameter.

Contribution

It introduces two novel analysis techniques for measuring B0s mixing frequency using polarized Z0 decays and combines them with a third method for improved exclusion limits.

Findings

Excluded Delta m_s < 7.6 ps^-1 at 95% CL

Excluded 11.8 < Delta m_s < 14.8 ps^-1 at 95% CL

Set constraints on B0s mixing frequency

Abstract

We set a preliminary 95% C.L. exclusion on the oscillation frequency of B0s - B0s-bar mixing using a sample of 400,000 hadronic Z0 decays collected by the SLD experiment at the SLC between 1996 and 1998. The analyses determine the b-hadron flavor at production by exploiting the large forward-backward asymmetry of polarized Z0 -> b b-bar decays as well as information from the hemisphere opposite that of the reconstructed B decay. In one analysis, B decay vertices are reconstructed inclusively with a topological technique,and separation between B0s and B0s-bar decays exploits the B0s -> Ds- cascade charge structure. In the other analysis, semileptonic decays are selected and the B decay point is reconstructed by intersecting a lepton track with the trajectory of a topologically reconstructed D meson. The two analyses are combined with a third analysis described elsewhere to exclude the following values of the B0s - B0s-bar mixing oscillation frequency: Delta m_s < 7.6 ps-1 and 11.8 < Delta m_s < 14.8 ps-1 at the 95% confidence level.