Colored bosons on top FBA and angular cross section for $t\bar{t}$ production

Abstract

With full data set that corresponds to an integrated luminosity of 9.4 fb${}^{-1}$, CDF has updated the top quark forward-backward asymmetry (FBA) as functions of rapidity difference $|\Delta y|$ and $t\bar{t}$ invariant mass $M_{t\bar{t}}$. Beside the sustained inconsistency between experiments and standard model (SM) predictions at large $|\Delta y|$ and $M_{t\bar{t}}$, an unexpected large first Legendre moment with $a_1=0.39\pm 0.108$ is found. In order to solve the large top FBA, we study the contributions of color triplet scalar and color octet vector boson. We find that the top FBA at $|\Delta y|>1$ and $M_{t\bar{t}}>450$ GeV in triplet and octet model could be enhanced to be around 30% and 20%, whereas the first Legendre moment is $a_1^{\mathbf{Di}}=0.38$ and $a_1^{\mathbf{Axi}}=0.23$, respectively.

Comments: 13 pages, 5 figures; references added