Flavour tagging techniques for CPV studies in the $B_s$ system with ATLAS

TL;DR

This paper discusses flavour tagging techniques used in ATLAS to improve sensitivity to $B_s$ meson mixing by distinguishing initial meson flavour, based on 2011 data, with methods calibrated on self-tagged decays.

Contribution

It presents the flavour tagging methods, their performance, and calibration procedures for $B_s$ mixing studies in ATLAS using LHC data.

Findings

Flavour tagging techniques enhance $B_s$ mixing sensitivity.

Calibration on $B^\pm$ decays improves tagging accuracy.

Performance metrics demonstrate effective tagging in ATLAS.

Abstract

The sensitivity to $B_s$ meson mixing phenomena can be significantly improved by distinguishing the initial meson flavour. The flavour tagging techniques used in the ATLAS measurement of the angular amplitudes contributing to $B_s \rightarrow J/\psi\phi$ decays are presented using 4.9 fb$^{-1}$ of $pp$ data at $\sqrt{s}$ = 7 TeV from 2011. The methods, their performance and calibration on self-tagged $B^\pm \rightarrow J/\psi K^\pm$ data are shown.