Top quark physics in the vector color-octet model

We study and constrain the parameter space of the vector color-octet model from the observed data at the Tevatron by studying the top quark pair production and associated observables A(FB)(t (t) over bar) and spin correlation. In particular we study the invariant mass and rapidity dependence of A(FB)(t (t) over bar) at the Tevatron. In addition to the flavor conserving (FC) couplings we extend our study to include the flavor violating (FV) coupling involving the first and third generation quarks for both these processes. In order to ensure that we remain within the constraints imposed by the LHC data, we analyze the charge asymmetry, p(T) spectrum and invariant mass in the t (t) over bar production data at the LHC. The constraints from the dijet resonance searches performed by the LHC are also considered. We also explore the contribution of this model to the single top quark production mediated by charged and neutral color-octet vector bosons. FV couplings introduced then induce the same-sign top-pair production process which is analyzed for both the hadron colliders. We have incorporated the effect of finite decay width of color octets on these processes. We find that it is possible to explain the observed A(FB)(t (t) over bar) anomaly in the color-octet vector model without transgressing the production cross sections of all these processes both through FC and FV couplings at the Tevatron. We predict best point sets in the model parameter space for specific choices of color-octet masses corresponding to chi(2)(min) evaluated using the m(t (t) over bar) and vertical bar Delta gamma vertical bar spectrum of A(FB)(t (t) over bar) from the observed data set of Run II of the Tevatron at the integrated luminosity 8.7 fb(-1). We find that the single top quark production is more sensitive to the FC and FV couplings in comparison to the top-pair production. We provide 95% exclusion contours on the plane of FV chiral couplings from the recent data from Tevatron, CMS and ATLAS corresponding to the nonobservability of large same-sign dilepton events. The four observed point sets are consistent with the cross section, charge asymmetry and spin-correlation measurements for t (t) over bar production and dijet searches at the LHC.