Phenomenology of the two Higgs doublet sector of a quark-lepton symmetric model

摘要

In the simplest examples of models with a discrete quark-lepton symmetry, an electroweak symmetry braking sector with more than one Higgs doublet is necessary to obtain the correct mass relations between quarks and leptons. A two Higgs doublet model version has flavour-nonconserving Yukawa couplings, which are proportional to the masses of the quark-lepton symmetric partners of the fermions. The main focus of this paper will be on flavour-changing leptonic decays, in particular those of muons since these give the most opportunity for experimental investigation. The neutral Higgs mediated decay (mu)(sup -) (yields) e(sup -) e(sup +)e(sup -) will be investigated at tree-level, as will the charged-Higgs contribution to the decay (mu) (sup -) (yields) (upsilon) (sub (mu)) e(sup -)(upsilon) (sup -)bar (sub e). A one-loop calculation of the process (mu) (yields) e (gamma) will be performed. This will lead on to an examination of the effect on the muon anomalous magnetic moment. Finally, the effect of the quark-lepton symmetric 2HDM contribution to b (yields) s (gamma) will briefly be considered. 10 refs., 2 figs. (Atomindex citation 26:018056)