Search for CP violation in the Bs - Bsbar system with LHCb

TL;DR

This paper reports on the search for CP violation in the Bs - Bsbar system using LHCb data, aiming to measure the mixing-induced CP-violating asymmetry in Bs decays, which could reveal physics beyond the Standard Model.

Contribution

It presents the methodology and initial results of a time-dependent angular analysis of Bs decays to measure CP violation, advancing the experimental efforts at LHCb.

Findings

Initial measurements of CP asymmetry in Bs decays

Constraints on New Physics models from the data

Development of analysis techniques for future precision

Abstract

The determination of the mixing induced CP-violating asymmetry in decays such as $B^0_s \to J/\psi \phi$ is one of the key goals of the LHCb experiment. Its value is predicted to be very small in the Standard Model but can be significantly enhanced in many models of New Physics. The steps towards a precise determination of this phase with a flavour-tagged, time-dependent, angular analysis of the decay $B^0_s \to J/\psi \phi$ will be presented, and first results shown from this measurement programme, using data collected in 2010 and the early months of the 2011 run. Results will also be shown, and prospects discussed, from related measurements.