Current status of top-specific variant axion model
Journal
Physical Review D
Journal Volume
97
Journal Issue
3
Date Issued
2018
Author(s)
Abstract
The invisible variant axion model is one of the very attractive models which solves the strong CP problem but does not provoke the domain wall problem. At the electroweak scale, this model requires at least two Higgs doublets, one of which carries a nonzero Peccei-Quinn (PQ) charge and the other is neutral. We consider a scenario where only the right-handed top quark is charged under the PQ symmetry and couples with the PQ-charged Higgs doublet. As a general prediction of this model, the top quark can decay to the observed standard model-like Higgs boson h and the charm or up quark, t→hc/u, which recently exhibited slight excesses at LHC run-I and run-II and will soon be testable at the LHC run-II. If the rare top decay excess stays at the observed central value, we show that tanβ∼1 or smaller is preferred by the Higgs data. The chiral nature of the Higgs flavor-changing interaction is a distinctive feature of this model and testable using the angular distribution of the t→ch decays at the LHC.
Type
journal article