Probing topcolor-assisted technicolor from top charge asymmetry and triple-top production at the LHC

Abstract

In a topcolor-assisted technicolor model (TC2) with large FCNC top quark couplings, we study its correlated contributions to the top quark forward-backward asymmetry ($A_{FB}$) at the Tevatron, the top charge asymmetry ($A_{C}$) and the triple-top production at the LHC. Under current constraints on the top quark from the LHC and Tevatron(such as the total and differential production rates), we scan the parameter space of such a TC2 model. We find that in the allowed parameter space the TC2 model can explain the Tevatron measured $A_{FB}$ at $2\sigma$ level, but meanwhile significantly enhance $A_{C}$ at the LHC. Such enhanced $A_{C}$, albeit currently allowed by the LHC measurement at $2\sigma$ level, will serve as a test of TC2 with the improvement of measurement precision at the LHC. Then with all the constraints (including the requirement to explain $A_{FB}$ at $2\sigma$ level and satisfying the current LHC measurement of $A_{C}$ at $2\sigma$ level), we find that the TC2 model can induce sizable triple-top production at the 14 TeV LHC (the production rate can maximally reach 16 pb). Due to the low SM backgrounds, the triple-top production can also be a good probe for TC2 model, complementary to $A_{C}$.Comment: 15 pages, 5 figures, new constraints from LHC addded, published version(Phys. Lett. B