Search for CP violation in the Bs/Bs-bar system

TL;DR

This paper reports on measurements of CP violation parameters in the Bs/Bs-bar system using LHCb data, including flavor tagging, CKM angle sin 2{eta}, and the weak phase {\phi}s, along with related decay observations.

Contribution

It introduces new measurements of the weak phase {\phi}s and related decay processes in the Bs system using early LHCb data, enhancing understanding of CP violation.

Findings

Measured B(B+ ightarrowJ/{\psi}{\pi}+)/B(B+ ightarrowJ/{\psi}K+) ratio.

First observation of B0s ightarrowJ/{\psi}f2'(1525).

Constrained {\phi}s through amplitude analysis of B0s ightarrow J/{\psi} {\phi} decays.

Abstract

We present studies from the LHCb experiment leading to the measurement of the weak phase {\phi}s. At first, flavor tagging is established by measuring the B0s oscillation frequency \Deltams. Then, flavor tagging is used to perform a measurement of the well known CKM angle sin 2{\beta} in B0 \rightarrow J/{\psi} KS0, before we constrain {\phi}s through an amplitude analysis of B0s \rightarrow J/{\psi} {\phi} decays. These studies use about 35 inverse pb of data taken in 2010. In addition, we present the measurement of B(B+\rightarrowJ/{\psi}{\pi}+)/B(B+\rightarrowJ/{\psi}K+) and the first observation of B0s \rightarrowJ/{\psi}f2'(1525).