Sizable stop mixing in flavored gauge mediation models with discrete non-Abelian symmetries

Abstract

We analyze a minimal flavored gauge mediation model in which the electroweak Higgs and messenger doublets are embedded in multiplets of a discrete non-Abelian symmetry. In this scenario, the minimal Higgs-messenger sector that is consistent with the 125 GeV Higgs mass has two vectorlike pairs of messenger fields. This scenario is obtained in a specific limit of the superpotential interactions of the Higgs-messenger fields and the matter fields. Due to the structure of the messenger-matter Yukawa couplings in this limit, sizable stop mixing and flavor-diagonal soft supersymmetry breaking parameters are achieved. In most of the parameter space, the masses of the colored superpartners are at most in the 5 − 6 TeV range. I. INTRODUCTIONThe 2012 discovery of the 125 GeV Higgs particle [1,2] and subsequent detailed measurements of its properties at the Large Hadron Collider (LHC) has provided significant limits on the allowed possibilities for extensions of the Standard Model (SM). In the context of theories with softly broken supersymmetry at the TeV scale (for reviews, see e.g. [3,4]), the Higgs mass is known to be within the theoretically allowed range for perturbative theories, but its relatively high value either requires large radiative corrections in the minimal supersymmetric standard model (MSSM), or an enlarged Higgs sector to boost the tree-level contributions. As such, it has long been known in the MSSM that large stop mixing or very heavy stops are needed (see e.g. [5]). This can place stringent constraints on specific models of the soft supersymmetry breaking terms, and also has important implications for the potential observability of superpartners at the LHC.The model-building constraints imposed by the Higgs measurements are particularly striking in the context of gauge mediation. In its minimal implementation, gauge-mediated supersymmetry breaking [6-9] predicts highly suppressed scalar trilinear couplings (A terms) at the messenger *

Flavored gauge mediation with discrete non-Abelian symmetries

“…As studied in [33], a key assumption of this scenario is that the three generations of SM quarks and leptons are embedded into doublet and singlet represenations of S 3 . The charge assignments for the fields in the theory is summarized in Table I.…”

“…As discussed in [33], one possible solution that guarantees two zero mass eigenvalues and one nonzero mass eigenvalue is to enforce the following constraints:…”

“…Discrete non-Abelian symmetries provide rigid constraints on these models, with implications not only for the flavor puzzle but also for the well-known µ/B µ problem of gauge mediation [34,35] (see [4,36] for reviews). In [32,33], we showed that three-family models based on S 3 require an expanded Higgs-messenger sector that results in two pairs of heavy messenger doublets, as well as the pair of light doublets that are to be identified as the Higgs fields H u,d of the MSSM. For the case of interest in which the MSSM matter superfields also are embedded within S 3 representations, various scenarios can be constructed with one heavy and two massless generations.…”

“…In this paper, we build upon [32,33] to explore the implications for the flavor puzzle within these scenarios in greater detail. Our focus in particular is on achieving a mass hierarchy for the lighter generations of quarks and charged leptons, and to obtain a reasonable value for the Cabibbo mixing angle of the quark sector (here we will ignore the issue of neutrino mass generation, and return to this question in future work).…”

“…The structure of this work is as follows. We begin with an overview of the discrete non-Abelian Higgs-messenger symmetry and the resulting model structure, focusing on the case of the discrete group S 3 , as in [17,32,33]. We present the model and discuss the generation of masses and mixing angles among the first and second quark families.…”