Signature of the Maximally Symmetric 2HDM via $W^{\pm}/Z$-Quadruplet Productions at the LHC

TL;DR

This paper explores the signatures of the Maximally Symmetric Two-Higgs Doublet Model (MS-2HDM) at the LHC, focusing on $W^{ m iny ext{±}}/Z$-pair production processes, and finds that heavy Higgs states can significantly enhance certain production channels.

Contribution

It provides the first detailed NLO QCD analysis of MS-2HDM signatures at the LHC, highlighting distinctive quadruplet production enhancements.

Findings

SM-like Higgs production aligns with the SM

Heavy Higgs states boost $W/Z$-quadruplet production at low transverse momentum

Analysis aids future discovery prospects of MS-2HDM

Abstract

We consider the Maximally Symmetric Two-Higgs Doublet Model (MS-2HDM) in which the so-called Standard Model (SM) alignment can be achieved naturally by the virtue of an SO(5) symmetry imposed on the 2HDM. We investigate the signature of the MS-2HDM via $p p \to HX \to VV^* X$ and $p p \to HHX \to VV^*V'V'^* X$ processes at the LHC for different values of $\tan \beta$. We perform our calculations with NLO QCD accuracy, using the \textsf{Herwig~7} multi-purpose event generator at $\sqrt{s}=13$~TeV center-of-mass energy. We show that the production of single SM-like Higgs bosons via $W^{\pm}/Z$-pairs is completely aligned with the SM. Interestingly, the presence of the heavy Higgs states significantly enhances the cross-section for the $W^{\pm}/Z$-quadruplet production channels in the low-$p_{\perp}$ regions. These vital analyses may aid the future discovery of this minimal and very predictive extension of the SM and can be generalised to other realisations of the 2HDM.