The S parameter for a Light Composite Higgs: a Dispersion Relation Approach
Abstract
We derive a dispersion relation for the S parameter in the SO(5)/SO(4) Minimal Composite Higgs model. This generalizes the Peskin-Takeuchi formula to the case when a light Higgs boson is present in the spectrum. Our result combines an IR effect due to the reduction in the Higgs boson couplings with a UV contribution from the strong sector. It also includes a finite matching term, achieving a very good relative accuracy O(m_h/m_\rho). We apply our formula in several toy examples, modeling the UV spectral density via Vector Meson Dominance.
Keywords
Cite
@article{arxiv.1211.5543,
title = {The S parameter for a Light Composite Higgs: a Dispersion Relation Approach},
author = {Axel Orgogozo and Slava Rychkov},
journal= {arXiv preprint arXiv:1211.5543},
year = {2015}
}
Comments
21 pages, no figures; v2: references added, typos corrected; v3: accuracy estimate revised, comparison with gauge formalism made more precise, other minor improvements, version to appear in JHEP; v4: misprints corrected, footnote added