Eur. Phys. J. C (2007) 50: 647-654
https://doi.org/10.1140/epjc/s10052-007-0232-8

Regular Article - Theoretical Physics

On electroweak symmetry breaking in the littlest Higgs model

¹ Departamento de Física Teórica I, Universidad Complutense de Madrid, 28040, Madrid, Spain
² Department of Physics, CERN TH Division, 1211, Geneva 23, Switzerland
³ IFIC – Instituto de Física Corpuscular, CSIC – Universitat de València, 46071, Valencia, Spain

^* e-mail: siannah.penaranda@cern.ch

Received: 17 August 2006
Revised: 9 November 2006
Published online: 20 February 2007

Abstract

In SU(5)/SO(5) little Higgs models radiative corrections give rise to SU(2)_L×U(1)_Y symmetry breaking. In this work we start a program for a detailed determination of the relevant terms of the effective Higgs potential by computing the contribution of the t, b and T quarks at the one-loop level, as a starting point for a higher-loop computation. In spite of the fact that some two-loop level contributions are well known to be important, we use our preliminary one-loop result to illustrate that, by demanding the effective potential to reproduce exactly the standard model Higgs potential, and in particular the relation m_H ²=2λv²=2μ², it will be possible to set new constraints on the parameter space of the littlest Higgs model when the computation of all the relevant contributions to the effective Higgs potential is completed.