Tevatron Asymmetry of Tops in a W',Z' Model

Abstract

Recent results from the CDF Collaboration indicate the the top-pair forward-backward asymmetry is largest in regions of high rapidity difference $|\Delta y|$ and invariant mass $M_{t\bar{t}}.$ We show that experimental observations can be explained by our previously proposed Asymmetric Left-Right Model (ALRM). The gauge symmetry $U^{\prime }(1)\times S{U}^{\prime }(2)\times SU(2)$ is broken by a triplet Higgs in the primed sector. The $W^{\prime }$ boson has a $(t,d)$ right-handed coupling and the $Z^{\prime }$ boson has diagonal fermion couplings. We determine the model parameters to be $M_{W^{\prime }}=700$ GeV, $M_{Z^{\prime }}=1$ TeV, and charged current coupling $g_2^{\prime }=3$. The $W^{\prime }$ and $Z^{\prime }$ total decay widths are of $\mathcal{O}(100$ GeV). The signals from $Z^{\prime }\to t\bar{t}$ and $W^{\prime }\to tb$ at the LHC will test the model.

Comments: 14 pages, 7 figures; typos corrected, references added. Version to appear in PLB