  Electroweak production of single top quarks is an as-yet-unverified
prediction of the Standard model, potentially sensitive to new physics. Two of
the single top quark productions channels have significant charge asymmetries
at the LHC, while the much larger background from $t\bar{t}$ is nearly
charge-symmetric. This can be used to reduce systematic uncertainties and make
precision measurements of single top quark production.
