Studies of CP-conserving and CP-violating Bs mixing parameters with the D0 experiment

TL;DR

This paper reports measurements of Bs meson mixing parameters, including the width difference and CP-violating phase, using data from the D0 experiment at Fermilab, providing insights into CP violation in the Bs system.

Contribution

First measurement of the CP-violating phase and width difference in Bs mixing using D0 Run IIa data, with combined results constraining these parameters.

Findings

Measured width difference ΔΓs = 0.13 ± 0.09 ps^{-1}

Set a constraint on the CP-violating phase φs = -0.70^{+0.47}_{-0.39}

Provided the first constraint on CP violation in Bs mixing

Abstract

This paper summarises the recent results of the Run IIa D0 experiment at the Tevatron Collider at Fermilab on the observable parameters of the $B_{s}$ meson. A measurement of the branching fraction $B_s->D_s^{(*)}D_s^{(*)}$ is reported, which provides an estimate of the width difference $\Delta\Gamma_{s}^{CP}/\Delta\Gamma_{s}$. Through the decay $B_{s} \to J/\psi \phi$ the width difference $\Delta\Gamma_{s}$ is extracted, and for the first time a constraint is set on the CP-violating phase $\phi_{s}$, although a four-fold ambiguity remains. This result is combined with other D0 measurements to yield $\Delta\Gamma_{s}=0.13\pm0.09 {\rm ps^{-1}}$, $\phi_{s} = -0.70^{+0.47}_{-0.39}$.