  Flavor-violating interactions involving new heavy particles are among
proposed explanations for the $t\bar t$ forward-backward asymmetry observed at
the Tevatron. Many of these models generate a $t\bar t$-plus-jet signal at the
LHC. In this paper we identify several new charge asymmetric variables in
$t\bar tj$ events that can contribute to the discovery of such models at the
LHC. We propose a data-driven method for the background, largely eliminating
the need for a Monte Carlo prediction of $t\bar t$-plus-jets, and thus reducing
systematic errors. With a fast detector simulation, we estimate the statistical
sensitivity of our variables for one of these models, finding that
charge-asymmetric variables could materially assist in the exclusion of the
Standard Model across much of the mass and coupling range, given 5 inverse fb
of data. Should any signal appear, our variables will be useful in
distinguishing classes of models from one another.
