We study the phenomenology of the Georgi-Machacek model at next-to-leading order (NLO) in QCD matched to parton shower, using a fully-automated tool chain based on MadGraph5_aMC@NLO and FeynRules. We focus on the production of the fermiophobic custodial fiveplet scalars H_5^0, H_5^+/-, and H_5^++/-- through vector boson fusion (VBF), associated production with a vector boson (V H_5), and scalar pair production (H_5 H_5). For these production mechanisms we compute NLO corrections to production rates as well as to differential distributions. Our results demonstrate that the Standard Model (SM) overall K-factors for such processes cannot in general be directly applied to beyond-the-SM distributions, due both to differences in the scalar electroweak charges and to variation of the K-factors over the differential distributions.
@article{arxiv.1512.01243,
title = {Automatic predictions in the Georgi-Machacek model at next-to-leading order accuracy},
author = {Celine Degrande and Katy Hartling and Heather E. Logan and Andrea D. Peterson and Marco Zaro},
journal= {arXiv preprint arXiv:1512.01243},
year = {2016}
}