2020 Impact factor 4.590
Particles and Fields
Eur. Phys. J. C 16, 635-639
DOI 10.1007/s100520000446

Mass scale of new physics in the absence of the Higgs boson

B.A. Kniehl - A. Sirlin

II. Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany

Received: 20 March 2000 / Revised version: 15 May 2000 /
Published online: 6 July 2000 - © Springer-Verlag 2000

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 $\sin^2\theta_{\mathrm{eff}}^{\mathrm{lept}}$ and MW, we show that, in a class of theories characterized by simple conditions, the upper bound on $\Lambda$ is close to or smaller than the upper bound on MH in the Standard Model, while in the complementary class $\Lambda$ is not restricted by our considerations. The issue of fine-tuning when $\Lambda$ is large is briefly discussed. Observations concerning the magnitude of the Higgs-boson contributions in the Standard Model are included. As a by-product of our considerations, we discuss the usefulness and important properties of a radiative correction, $\Delta r_{\mathrm{eff}}$, that directly links $\sin^2\theta_{\mathrm{eff}}^{\mathrm{lept}}$ with $\alpha$, $G_\mu$, and MZ.

Copyright Società Italiana di Fisica, Springer-Verlag 2000