We study gauge mediation of supersymmetry breaking in SU(5) supersymmetric grand unified theory with gauge fields as messengers. The generated soft supersymmetry breaking parameters lead to close to maximal mixing scenario for the Higgs mass and highly red
2.1Large(maximal)mixinginmodels
Sincetheradiativelygeneratedmaximalmixingscenariocaninprincipleeliminate netuningofEWSBcompletely,itisdesirabletoseewhetheritispossibletogetevenclosetoitinspeci cmodels.
ItiseasytoseethatthissolutiondoesnotexistinmSUGRA.Asaconsequenceofuniversalitiesingauginoandscalarmasses,whenstopmasssquaredisnegativeenoughtogeneratemaximalstopmixingattheEWscaleradiatively,sleptonsremaintachyonicevenattheEWscalebecausethebinocontributiontotherunningofsleptonmassesissmall.TheEWscalesleptonmassism2e 22
RGeVgivesthefollowinginequality m0+0.15M1/2[17].Imposingtheslepton
massbound100
m20≥ (0.4)2+(100GeV