Top A FB at the Tevatron vs. charge asymmetry at the LHC in chiral U(1) flavor models with flavored Higgs doublets

Abstract

We consider the top forward-backward (FB) asymmetry at the Tevatron and top charge asymmetry at the LHC within chiral U(1)′ models with flavor-dependent U(1) ′ charges and flavored Higgs fields, which were introduced in the Ref. [68]. In this model, one has to include the flavor changing couplings of the Higgs bosons as well as the Z ′ to the up-type quarks. The models could enhance not only the top forward-backward asymmetry at Tevatron, but also the top charge asymmetry at LHC, without too large same-sign top-quark pair production rates. Also the m tt distribution at high m tt show less deviations from the SM predictions. We identify parameter spaces for the U (1) ′ gauge boson and (pseudo)scalar Higgs bosons where all the experimental data could be accommodated, including the case with about 125 GeV Higgs boson, as suggested recently by ATLAS and CMS.

A resolution of the flavor problem of two Higgs doublet models with an extra U(1)H symmetry for Higgs flavor

“…In fact, the present authors recently constructed a new class of multi-Higgs doublet models which were designed to accommodate the top forward-backward asymmetry at the Tevatron without conflict with the upper bounds on the same sign top pair production at the LHC [6,7,24]. The model was based on the flavor dependent leptophobic U (1)…”

“…X can have the Yukawa couplings, λ ij Xq Li U Rj , which allow the extra quark to decay. We can avoid tree-level FCNC contributions if X does not get VEV, and X becomes a cold dark matter (CDM) candidate [6,7].…”

“…The set similar to the Type-II model could cancel the anomaly, changing the charge assignment of the extra fields properly, and good cold dark matter candidates could be realized, as mentioned in Refs. [6,7].…”

“…Some of these extra new particles might have influences on the production rates and decay branching ratios of Higgs bosons. In certain models, we find that some particles are stable and can play a role of nonbaryonic cold dark matter of the universe [6,7].…”

“…These issues are more model-dependent, and more careful study on the Higgs boson phenomenology is required for each type of 2HDMs proposed in this Letter. This is left for a future work [11].…”