Charged Z ′ to conciliate the apparent disagreement between t t ¯ Tevatron forward-backward asymmetry and LHC charge asymmetry

Abstract

We propose a charged, electrically neutral, and flavour changing Z´ model to conciliate the apparent disagreement between the important excess found in the tt¯ Tevatron forward-backward asymmetry and the null ?compatible with negative? results found in the LHC charge asymmetry. We show that this model contributes positively to the forwardbackward asymmetry, whereas naturally a new cancellation is turned on at the LHC, yielding a null, or even negative, charge asymmetry. We found the region in parameter space that is simultaneously allowed by the stringent Tevatron and LHC observables. We show that the model is safe to atomic parity violation constraints and to tj/tj¯ resonance searches, and propose a possible increase in the Z´ width to avoid ttj¯ constraints. We evaluate the constraints to the model, as well as distinctive features in the fore-coming experimental results.