Constrained SUSY seesaws with a 125 GeV Higgs

M. Hirsch,A. Vicente,F. R. Joaquim

doi:10.1007/jhep11(2012)105

Abstract

Abstract Motivated by the ATLAS and CMS discovery of a Higgs-like boson with a mass around 125 GeV, and by the need of explaining neutrino masses, we analyse the three canonical SUSY versions of the seesaw mechanism (type I, II and III) with CMSSM boundary conditions. In type II and III cases, SUSY particles are lighter than in the CMSSM (or the constrained type I seesaw), for the same set of input parameters at the universality scale. Thus, to explain $ {m_{{{h^0}}}}\simeq 125 $ GeV at low energies, one is forced into regions of parameter space with very large values of m 0, M 1/2 or A 0. We compare the squark and gluino masses allowed by the ATLAS and CMS ranges for $ {m_{{{h^{{^0}}}}}} $ (extracted from the 2011-2012 data), and discuss the possibility of distinguishing seesaw models in view of future results on SUSY searches. In particular, we briefly comment on the discovery potential of LHC upgrades, for squark/gluino mass ranges required by present Higgs mass constraints. A discrimination between different seesaw models cannot rely on the Higgs mass data alone, therefore we also take into account the MEG upper limit on BR(μ → eγ) and show that, in some cases, this may help to restrict the SUSY parameter space, as well as to set complementary limits on the seesaw scale.

Highlights

Mixing [7, 10, 16, 31, 32]
A discrimination between different seesaw models cannot rely on the Higgs mass data alone, we take into account the MEG upper limit on branching ratio (BR)(μ → eγ) and show that, in some cases, this may help to restrict the SUSY parameter space, as well as to set complementary limits on the seesaw scale
The renormalization group (RG) flow of all Yukawa couplings and mass parameters is modified with respect to the constrained minimal supersymmetric standard model (CMSSM) case [118,119,120,121,122]

Summary

Introduction

Mixing [7, 10, 16, 31, 32]. In the latter case, the lightest stop could still be relatively light, say mt1 >∼ 500 GeV [45]. The main purpose of this work is to investigate whether imposing a Higgs mass around 125 GeV allows to some extent to differentiate the CMSSM from the constrained SUSY seesaws and whether type II and III seesaws are distinguishable among themselves. We will complement this analysis by imposing the MEG constraint on the branching ratio of the radiative lepton flavour violating decay Br(μ → eγ) ≤ 2.4 × 10−12 [80].

Objectives

Results

Conclusion