W+charm production with massive c quarks in PowHel

Understand

The hadroproduction of a $W$ boson in association with a charm quark at the Large Hadron Collider is at the centre of current investigations due to its potential to probe the strangeness content of the proton.

• In this paper we present an implementation of the $W+c$ production process in the PowHel event generator matched to the PYTHIA8 parton shower approach, allowing to obtain predictions for differential cross-sections with NLO QCD accuracy matched to the accuracy of the Shower Monte Carlo event generator.
• Effects of non-diagonal CKM matrix elements, finite charm quark mass and off-shell $W$ decays including spin correlations are taken into account.
• We investigate the production of a leptonically decaying $W$ boson in association with either a charmed meson ($W^\pm~+~D^{*\mp}$) or a charmed jet ($W^\pm~+~j_{c}$) and compare our predictions with particle-level measurements by the ATLAS and CMS collaborations at $\sqrt{s} =$ 7 and 13 TeV.