Measurements of the top quark mass with the ATLAS detector

TL;DR

This paper reports precise measurements of the top quark mass using ATLAS data at 7 and 8 TeV, including an extraction of the pole mass at NLO and combined results with a total uncertainty of 0.70 GeV.

Contribution

It provides new top quark mass measurements from multiple channels and an NLO extraction of the pole mass, improving precision and systematic understanding.

Findings

Top quark pole mass: 173.2 GeV with uncertainties

Combined top quark mass: 172.84 GeV with 0.70 GeV total uncertainty

Systematic effects dominate the uncertainty budget

Abstract

The measurements of the top quark mass given are obtained from ATLAS data taken at proton--proton centre-of-mass energies of $\sqrt{s}=7$ and $8$ TeV. An extraction of the top quark pole mass ($m_{\mathrm{top}}^{\mathrm{pole}}$) at next-to-leading order (NLO) is presented. This result is obtained from normalised differential cross-sections in the $t\bar{t}\to\mbox{dilepton}$ channel leading to: $m_{\mathrm{top}}^{\mathrm{pole}} = 173.2 \pm 0.9 (\mathrm{stat.}) \pm 0.8 (\mathrm{syst.}) \pm 1.2 (\mathrm{theo.})$ GeV. In addition, measurements of $m_{\mathrm{top}}$ are discussed that are based on the template method performed in three $t\bar{t}$ decay channels. For all results the uncertainty is dominated by systematic effects. Finally, the 2016 ATLAS combined value of $m_{\mathrm{top}}$ is: $m_{\mathrm{top}}=172.84 \pm 0.34 (\mathrm{stat.}) \pm 0.61 (\mathrm{syst.})$ GeV,with a total uncertainty of 0.70 GeV, i.e. a precision of 0.4$\%$.