$B$ flavour tagging using charm decays at the LHCb experiment

TL;DR

This paper presents a new algorithm for determining the initial flavor of neutral B mesons at the LHCb experiment by analyzing charm decays, achieving a tagging power of about 0.30%.

Contribution

The paper introduces a charm-based flavor tagging algorithm calibrated with LHCb data, enhancing B meson analysis capabilities.

Findings

Tagging power of 0.30% on B→J/ψ X decays.

Calibration performed using 3.0 fb^{-1} of data at 7 and 8 TeV.

Algorithm exploits correlation between B flavor and charm hadron charge.

Abstract

An algorithm is described for tagging the flavour content at production of neutral $B$ mesons in the LHCb experiment. The algorithm exploits the correlation of the flavour of a $B$ meson with the charge of a reconstructed secondary charm hadron from the decay of the other $b$ hadron produced in the proton-proton collision. Charm hadron candidates are identified in a number of fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is calibrated on the self-tagged decay modes $B^+ \to J/\psi \, K^+$ and $B^0 \to J/\psi \, K^{*0}$ using $3.0\mathrm{\,fb}^{-1}$ of data collected by the LHCb experiment at $pp$ centre-of-mass energies of $7\mathrm{\,TeV}$ and $8\mathrm{\,TeV}$. Its tagging power on these samples of $B \to J/\psi \, X$ decays is $(0.30 \pm 0.01 \pm 0.01) \%$.