Constraining models with a large scalar multiplet
High Energy Physics - Phenomenology
2013-07-17 v2
Abstract
Models in which the Higgs sector is extended by a single electroweak scalar multiplet X can possess an accidental global U(1) symmetry at the renormalizable level if X has isospin T greater or equal to 2. We show that all such U(1)-symmetric models are excluded by the interplay of the cosmological relic density of the lightest (neutral) component of X and its direct detection cross section via Z exchange. The sole exception is the T=2 multiplet, whose lightest member decays on a few-day to few-year timescale via a Planck-suppressed dimension-5 operator.
Cite
@article{arxiv.1303.1244,
title = {Constraining models with a large scalar multiplet},
author = {Kevin Earl and Katy Hartling and Heather E. Logan and Terry Pilkington},
journal= {arXiv preprint arXiv:1303.1244},
year = {2013}
}
Comments
20 pages, 5 figures. Additional constraints from Higgs decay, typos corrected in Eqs. 26 and A3, refs added, version accepted by PRD