Measurement of the Charge Asymmetry in Top Quark Pair Production

TL;DR

This paper measures the charge asymmetry in top quark pair production at the LHC using CMS data, comparing results with standard model predictions to test the theory's accuracy.

Contribution

It provides the first measurement of the charge asymmetry in top quark pairs at the LHC with detailed analysis and comparison to theoretical predictions.

Findings

Measured charge asymmetry consistent with standard model

Used novel unfolding technique for analysis

Analyzed data with electron/muon and multiple jets signature

Abstract

We present a measurement of the charge asymmetry in top quark pair production using an integrated luminosity of 1.09 fb-1 collected with the CMS detector. Top quark pairs with a signature of one electron or muon and four or more jets, at least one of them b tagged, are selected. At the LHC a small charge asymmetry in the rapidity distributions of top and antitop quarks is predicted. Therein slightly broader rapidity distributions for top quarks are expected, while antitop quarks are produced more centrally and possess narrower rapidity distributions. We determine the charge asymmetry based on two different sensitive variables and the results are compared with the most precise standard model theory predictions using a dedicated unfolding technique.