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

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 $pp\to HX\to V{V}^{\ast }X$ and $pp\to HHX\to V{V}^{\ast }{V}^{\prime }{V}^{\prime \ast }X$ 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.

Comments: 20 pages, 12 figures