Di-Electron Production at the LHC: Unravelling Virtual-Photon and Heavy-Flavour Contributions

Abstract

The production of virtual photons is a sensitive probe of the properties of the quark-gluon plasma. Experimentally they are detected via lepton pairs, which suffer from a large background arising from hadron decays. We calculate direct contributions from virtual photons produced via the Drell-Yan process with an additional jet using POWHEG, finding significant effects at low invariant masses, and simulate background contributions from charm- and bottom-quark pair production, quantifying theoretical uncertainties from scale variations and parton distribution functions. We find larger uncertainties for charm- than for bottom-quark contributions.