Top Quarks and Electroweak Symmetry Breaking in Little Higgs Models
Maxim Perelstein, Michael E. Peskin, Aaron Pierce
TL;DR
The paper investigates how Little Higgs models realize electroweak symmetry breaking with a pseudo-Goldstone Higgs, concentrating on the top quark sector and its heavy partner T. It shows that top-sector dynamics can generate a negative Higgs mass-squared while canceling one-loop quadratic divergences, through an SU(3) global symmetry and a Lagrangian that mixes the Standard Model top with a vector-like partner. The authors derive the relation between Higgs-top couplings and the heavy-top couplings, explicitly computing the t–T mixing parameters λ1, λ2 and the resulting λ_t and λ_T, and discuss the resulting phenomenology and experimental tests. They propose LHC tests via production and decays of the T, with measurements of widths and cross sections to probe the underlying EWSB mechanism and top-sector structure, while considering precision electroweak constraints on T.
Abstract
`Little Higgs' models, in which the Higgs particle arises as a pseudo-Goldstone boson, have a natural mechanism of electroweak symmetry breaking associated with the large value of the top quark Yukawa coupling. The mechanism typically involves a new heavy SU(2)_{L} singlet top quark, T. We discuss the relationship of the Higgs boson and the two top quarks. We suggest experimental tests of the Little Higgs mechanism of electroweak symmetry breaking using the production and decay of the T at the Large Hadron Collider.