Measurement of the top quark mass using proton-proton data at sqrt(s) = 7 and 8 TeV

TL;DR

This paper reports precise measurements of the top quark mass using proton-proton collision data at 7 and 8 TeV from the CMS experiment, combining multiple decay channels and analyzing kinematic dependencies.

Contribution

It provides the most accurate top quark mass measurement to date by combining results from different decay channels and collision energies, with detailed systematic analysis.

Findings

Top quark mass measured as 172.44 GeV with ~0.5 GeV total uncertainty.

No kinematic bias observed in the top quark mass measurements.

Results are consistent with current theoretical models of top quark production.

Abstract

A new set of measurements of the top quark mass are presented, based on the proton-proton data recorded by the CMS experiment at the LHC at sqrt(s) = 8 TeV corresponding to a luminosity of 19.7 inverse femtobarns. The top quark mass is measured using the lepton + jets, all-jets and dilepton decay channels, giving values of 172.35 +/- 0.16 (stat) +/- 0.48 (syst) GeV, 172.32 +/- 0.25 (stat) +/- 0.59 (syst) GeV, and 172.82 +/- 0.19 (stat) +/- 1.22 (syst) GeV, respectively. When combined with the published CMS results at sqrt(s) = 7 TeV, they provide a top quark mass measurement of 172.44 +/- 0.13 (stat) +/- 0.47 (syst) GeV. The top quark mass is also studied as a function of the event kinematical properties in the lepton + jets decay channel. No indications of a kinematic bias are observed and the collision data are consistent with a range of predictions from current theoretical models of t t-bar production.