Chiral U(1) flavor models and flavored Higgs doublets: the top FB asymmetry and the W jj

Abstract

We present U (1) flavor models for leptophobic Z ′ with flavor dependent couplings to the right- We also show that the extension could realize cold dark matter candidates.

B → D (*) τν and B → τν in chiral U(1)′ models with flavored multi Higgs doublets

“…[18,19], the present authors proposed flavor models with extra Higgs fields, where gauged U(1) ′ symmetry forbids the potentially problematic FCNCs for B-B and K-K mixings but allows certain amounts of FCNCs which are still consistent with experimental data, by slightly breaking the criteria of ref. [17].…”

“…There, neutral CP-even scalars and a CP-odd scalar can have large (t, q) q=u,c,t elements of Yukawa couplings. Their tree-level mediations enhance the top forward-backward asymmetry (A t FB ) at the Tevatron, while accommodating with the newest strong constraints from LHC thanks to the destructive interference among the scalars [18][19][20][21]. In previous works, phenomenology of the charged Higgs boson in our models was not considered carefully because the charge Higgs boson cannot have sizable contribution to the top quark production at hadron colliders.…”

“…In section 2, we give a brief review of our models proposed in refs. [18,19]. We assign family dependent U(1) ′ charges to the right-handed (RH) up-type quarks in order to generate flavor changing Z ′ − u R − t R couplings in the mass eigenstates.…”

“…Then we will immediately realize that it is mandatory to introduce extra U(1) ′ -charged Higgs doublets in order to write Yukawa couplings for the up-type quarks including top quark, which have been first realized in refs. [18,19]. Thus we are led to multi-Higgs doublet models in the presence of a new spin-1 Z ′ boson with chiral couplings to the SM fermions.…”

“…In refs. [17][18][19], gauged U(1) ′ symmetry is assigned to the SM fermions and newly introduced extra Higgs doublets instead of Z 2 symmetry. Especially, in refs.…”