Identification of beauty and charm quark jets at LHCb

TL;DR

This paper evaluates the performance of algorithms for identifying beauty and charm quark jets at LHCb, demonstrating their efficiency and misidentification rates using real collision data from 2011 and 2012.

Contribution

It provides the first detailed performance measurements of b- and c-jet identification algorithms using LHCb data from 7 and 8 TeV collisions.

Findings

b-jet identification efficiency ~65%

c-jet identification efficiency ~25%

Misidentification rate for light jets ~0.3%

Abstract

Identification of jets originating from beauty and charm quarks is important for measuring Standard Model processes and for searching for new physics. The performance of algorithms developed to select $b$- and $c$-quark jets is measured using data recorded by LHCb from proton-proton collisions at $\sqrt{s}=7$ TeV in 2011 and at $\sqrt{s}=8$ TeV in 2012. The efficiency for identifying a $b(c)$ jet is about 65%(25%) with a probability for misidentifying a light-parton jet of 0.3% for jets with transverse momentum $p_{\rm T} > 20$ GeV and pseudorapidity $2.2 < \eta < 4.2$. The dependence of the performance on the $p_{\rm T}$ and $\eta$ of the jet is also measured.