New spectra in the HEIDI Higgs models

Abstract

We study the so-called HEIDI models, which are renormalizable extensions of the standard model with a higher dimensional scalar singlet field. As an additional parameter we consider a higher-dimensional mixing mass parameter. This leads to enriched possibilities compared to a previous study. We find effective spectral densities of the Higgs propagator, consisting of one, two or no particle peaks, together with a continuum. We compare with the LEP-2 data and determine for which range of the model parameters the data can be described. Assuming two peaks to be present we find for the new mass scale $\nu \approx 56\pm 12\text{gev}$, largely independent of the dimension. In the limiting case of $d\to 6$ and two peaks we find a higher dimensional coupling constant ${\alpha }_6=0.70\pm 0.18$, indicative of strong interactions among the higher dimensional fields. The LHC will not be able to study this Higgs field.

Comments: 17 pages, 4 figures