Top quark charge asymmetry: searching for light axigluons in tt + jet production at the LHC

We investigate the discovery potential of light color-octet bosons in the mass range of 100-400 GeV in exclusive top-pair plus jet production at the LHC, pp → tt + jet . We study the impact of such bosons on the incline, the energy and the rapidity asymmetries. We show that light axigluons with large couplings to quarks can be discovered at the LHC with a luminosity of a few fb −1 . Almost all of the considered axigluon parameter space can be probed using the already available 2011/2012 LHC data. In a small-coupling scenario, axigluons could be discovered using the charge asymmetry with 65 fb −1 at the LHC and a center of mass energy of 14 TeV. We furthermore show that tt + jet production could reveal the existence of scenarios where axigluons couple with a different strength to up-and down-type quarks.