Automatic predictions in the Georgi-Machacek model at next-to-leading order accuracy

TL;DR

This paper presents automated NLO QCD predictions for scalar production in the Georgi-Machacek model, highlighting the importance of process-specific K-factors for accurate phenomenology in collider experiments.

Contribution

It introduces a fully-automated computational framework for NLO predictions in the Georgi-Machacek model, focusing on scalar production processes and their differential distributions.

Findings

NLO corrections significantly affect production rates.

Standard Model K-factors are not directly applicable to BSM distributions.

Differential K-factors vary across different processes.

Abstract

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.