Triplet extended supersymmetric standard model

Abstract

We revisit an extension of the MSSM by adding a hypercharge-neutral, SU (2)-triplet chiral superfield. Similar to the NMSSM, the triplet gives an additional contribution to the quartic coupling in the Higgs potential, and the mass of the lightest CP -even Higgs boson can be greater than MZ at tree-level. In addition to discussing the perturbativity, fine-tuning, and decoupling issues of this model, we compute the dominant 1-loop corrections to the mass of the lightest CP -even Higgs boson from the triplet sector. When the Higgs-Higgs-Triplet coupling in the superpotential is comparable to the top Yukawa coupling, we find that the Higgs mass can be as heavy as 140 GeV even without the traditional contributions from the top-s-top sector, and at the same time consistent with the precision electroweak constraints. At the expense of having Landau poles before the GUT scale, this opens up a previously forbidden region in the MSSM parameter space where both s-tops are light. In addition to having relatively small fine-tuning (about one part in 30), this leads to a gluo-philic Higgs boson whose production via gluon-gluon fusion at the LHC can be twice as large as the SM In this paper, we extend the MSSM with a hypercharge-neutral, SU (2)-triplet chiral superfield T and name the model triplet-extended supersymmetric standard model (TESSM). Extensions of this type have been studied extensively by Espinosa and Quiros [29][30], Felix-Beltran [31], Setzer and Spinner [32], and Diaz-Cruz et al. [33]. While this model does not solve the µ-problem, it is an interesting alternative to the NMSSM, as an economical extension of the MSSM, because it can also achieve a mass of the lightest CP -even Higgs boson that is larger than M Z at tree level. Furthermore, compared to the MSSM and the NMSSM, we expect there to be more radiative corrections to the mass of the lightest CP -even Higgs boson due to the additional states in the triplet. To the extent that these triplet-induced radiative corrections are significant, we may further alleviate the little hierarchy problem.Unfortunately, in both the NMSSM and the TESSM, the respective singlet-induced and triplet-induced radiative corrections are typically small when we demand perturbativity at the scale of grand unified theory (GUT) near 10 16 GeV. This is because perturbativity at the GUT scale imposes the bound λ < ∼ 0.7 at the weak scale, where λ is respectively the Higgs-singlet-Higgs and the Higgs-triplet-Higgs coupling in the superpotential of the NMSSM and TESSM. In both models, while the tree-level mass of the lightest CP -even Higgs boson can be as large as 100 GeV, the O(λ 4 ) radiative corrections are not large enough to lift the Higgs mass over the LEP bounds. On the other hand, in the TESSM, when we have λ ∼ 0.9 (so that λ is comparable with the top Yukawa coupling)at the weak scale, we find the tree-level mass of the lightest CP -even Higgs boson to be close to the LEP bound and the O(λ 4 ) radiative corrections alone can easily lift the Higgs mass over the LEP bound even wit...

Perspectives on a supersymmetric extension of the standard model with a Y = 0 Higgs triplet and a singlet at the LHC

“…In particular, the addition of a Y = 0 hypercharge superfield gives large tree-level as well as one-loop corrections to the Higgs masses, and relaxes the fine tuning problem of the MSSM by requiring a lower SUSY mass scale [38][39][40]. There are some special features of these extensions which are particularly interesting and carry specific signatures.…”

Multi-lepton signatures of the triplet like charged Higgs at the LHC

“…In this region the tree level triplet contribution to the Higgs mass is maximized with large values of λ [33,34] so that as sizable loop corrections as in the case of MSSM are not needed. Table 1 shows the benchmark points chosen for our collider study in the next section.…”

“…It was shown in refs. [33,34] that it is possible to obtain the lightest Higgs boson with a mass up to 125 GeV even at tree level when λ is so large that the model is in the non-perturbative regime at the high scales. As long as we demand perturbativity of the model, for a 125 GeV Higgs one needs radiative corrections to the neutral Higgs sector which, however, are not necessarily as large as those in the MSSM [31-33, 35, 38].…”

“…coming both from the colored sector and the electroweak sector since it is known that for TESSM the neutralino and chargino corrections can have crucial impact on the lightest Higgs mass [31,33,34]. For the numerical calculations, we use an effective formula for the 1-loop contributions to the CP even scalar mass matrix [33,34] (∆M…”

“…For the numerical calculations, we use an effective formula for the 1-loop contributions to the CP even scalar mass matrix [33,34] (∆M…”