Effective Mass Scale of New Physics in the Absence of the Higgs Boson

TL;DR

This paper explores the constraints on the scale of new physics in a universe without the Higgs boson, using electroweak precision measurements to establish bounds on the hypothetical mass scale Lambda.

Contribution

It introduces a framework to constrain the new physics scale Lambda in Higgsless models using electroweak precision data, highlighting conditions under which Lambda is limited.

Findings

Upper bound on Lambda close to SM Higgs mass upper bound in certain theories

Lambda not restricted in some classes of models

Discusses the role of radiative correction Delta r_eff in electroweak measurements

Abstract

We consider a hypothetical scenario in which the Higgs boson is absent, and attempt to constrain the mass scale Lambda of the new physics that would take its place. Using recent measurements of sin^2(theta_eff^lept) and M_W, we show that, in a class of theories characterized by simple conditions, the upper bound on Lambda is close to or smaller than the SM upper bound on M_H, while in the complementary class Lambda is not restricted by our considerations. The issue of fine-tuning when Lambda is large is briefly discussed. As a by-product of our considerations, we discuss the usefulness and important properties of a radiative correction, Delta r_eff, that directly links sin^2(theta_eff^lept) with alpha, G_mu, and M_Z.