Effective operators in t-channel single top production and decay.

The production of a single top quark in the t-channel and its subsequent decay is studied at NLO accuracy in QCD, augmented with the relevant dimension-6 effective operators from the Standard Model Effective Theory. We examine various kinematic and angular distributions for proton-proton collisions at the LHC at 13 TeV, in order to assess the sensitivity to these operators, both with and without the top quark narrow width approximation. Our results will be helpful when devising strategies to establish bounds on their coefficients, including the amount of CP violation of the weak dipole operator.

Charm production in association with an electroweak gauge boson at the LHC.

The production of charm quark jets in association with electroweak gauge bosons at the LHC can be used as a tool to constrain quark parton distribution functions (PDFs). Motivated by recent measurements at the Tevatron and LHC, we calculate cross sections for W/Z+c, comparing these to W/Z+jet, for various PDF sets. The cross-section differences can be understood in terms of the different underlying PDFs, with the strange quark distribution being particularly important for W+c production. We suggest measurements of appropriately defined ratios and comment on how these measurements at the LHC can be used to extract information on the strange and charm content of the proton at high Q(2) scales.