CONICET | Buscador de Institutos y Recursos Humanos

We present a phenomenological analysis of the recent Tevatron resultson the $tar t$ forward-backward asymmetry and invariant-massspectrum assuming a new contribution from an $s$-channel gluon resonance with a mass in the range from $700$ to $2500$ GeV. In contrast tomost of the previous works, this analysis shows that for masses below $sim 1$ TeVresonant New Physics could accommodate the experimental data. Ingeneral, we find that axial-like couplings are preferred for light andtop quark couplings, and that only top quark couples strongly to NewPhysics. We find that composite model scenarios arise naturally fromonly phenomenological analyses of the experimental results. We showthat our results are compatible with recent LHC limits in dijet and$tar t$ production, and find some tension for large resonance mass$sim 2.5$ TeV. We indicate as best observables for discriminatinga relatively light new gluon a better resolution in CDF forward-backwardasymmetry, as well as the $tar t$ charge asymmetry and invariant-massspectrum at the LHC.