Measurement of the cross-section for producing a $W$ boson in association with a single top quark in $pp$ collisions at $\sqrt{s}={13}$ TeV with ATLAS

Understand

The inclusive cross-section for the associated production of a $W$ boson and top quark is measured using data from proton-proton collisions at $\sqrt{s}={13}$ TeV.

• The dataset corresponds to an integrated luminosity of 3.2 fb$^{-1}$, and was collected in 2015 by the ATLAS detector at the Large Hadron Collider at CERN.
• Events are selected requiring two opposite sign isolated leptons and at least one jet; they are separated into signal and control regions based on their jet multiplicity and the number of jets that are identified as containing $b$ hadrons.
• The $Wt$ signal is then separated from the $t\bar{t}$ background using boosted decision tree discriminants in two regions.