Measurement of the t t-bar production cross section and the top quark mass in the dilepton channel in pp collisions at sqrt(s) =7 TeV

TL;DR

This paper reports measurements of the top quark pair production cross section and mass in proton-proton collisions at 7 TeV using CMS data, confirming consistency with the Standard Model predictions.

Contribution

First measurement of top quark pair production cross section and mass in the dilepton channel at 7 TeV with CMS, employing two different reconstruction methods.

Findings

Cross section measured as 168 +/- 18 (stat.) +/- 14 (syst.) +/- 7 (lumi.) pb.

Top quark mass measured as 175.5 +/- 4.6 (stat.) +/- 4.6 (syst.) GeV/c^2.

Results are consistent with Standard Model predictions.

Abstract

The t t-bar production cross section and top quark mass are measured in proton-proton collisions at sqrt(s) = 7 TeV in a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected by the CMS experiment. The measurements are performed in events with two leptons (electrons or muons) in the final state. Results of the cross section measurement in events with and without b-quark identification are obtained and combined. The measured value is sigma(t t-bar)=168 +/- 18 (stat.) +/- 14 (syst.) +/- 7 (lumi.) pb, consistent with predictions from the standard model. The top quark mass m(top) is reconstructed with two different methods, a full kinematic analysis and a matrix weighting technique. The combination yields a measurement of m(top)=175.5 +/- 4.6 (stat.) +/- 4.6 (syst.) GeV/c^2.