A minimal little Higgs model

Abstract

We discuss a little Higgs scenario that introduces below the TeV scale just the two minimal ingredients of these models, a vectorlike $T$ quark and a singlet component (implying anomalous couplings) in the Higgs field, together with a pseudoscalar singlet $\ensuremath{\eta}$. In the model, which is a variation of Schmaltz's simplest little Higgs model, all the extra vector bosons are much heavier than the $T$ quark. In the Yukawa sector the global symmetry is approximate, implying a single large coupling per flavor, whereas in the scalar sector it is only broken at the loop level. We obtain the one-loop effective potential and show that it provides acceptable masses for the Higgs $h$ and for the singlet $\ensuremath{\eta}$ with no need for an extra $\ensuremath{\mu}$ term. We find that ${m}_{\ensuremath{\eta}}$ can be larger than ${m}_{h}/2$, which would forbid the (otherwise dominant) decay mode $h\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\eta}$.