Comment on the CMS search for charge-asymmetric production of W' boson in ttbar + jet events

Understand

A reanalysis is presented on the CMS result on a search for a W' boson that couples to the top and down quarks.

• The model is motivated by the Tevatron results on the forward-backward asymmetry of ttbar pair production.
• In the evaluation of the theoretical cross section of pp -> ttbar + j, the interference effect between the SM and W' amplitudes is shown to be important, though it is ignored in the CMS analysis.
• The lower mass bound on the W' boson is relaxed from 840 GeV to 740 GeV at the 95% C.L.