Study of correlation of PDF uncertainty in single top and top pair production at the LHC

The incomplete knowledge of parton distribution functions is an important source of systematic uncertainty for top-quark measurements, including top-quark pair and single top-quark production cross sections, as well as for analyses that have a large background from these processes. The correlation of the parton-distribution-function uncertainty is studied for top-quark pair production and single top-quark production in association with a W boson, in final states with two reconstructed leptons. Four types of correlation are studied: between total production cross-sections, between cross-section and acceptance correction, between the two processes for common selection requirements, and between different jet multiplicity requirements. The uncertainty correlation is evaluated for several sets of parton distribution functions using simulated samples of top-quark pair and single top-quark events.