ep - p h / 93 06 24 2 v 1 7 J un 1 99 3 Natural Suppression of Higgsino - Mediated Proton Decay in Supersymmetric SO ( 10 ) ∗
نویسندگان
چکیده
In supersymmetric Grand Unified Theories, proton decay mediated by the color–triplet higgsino is generally problematic and requires some fine–tuning of parameters. We present a mechanism which naturally suppresses such dimension 5 operators in the context of SUSY SO(10). The mechanism, which implements natural doublet–triplet splitting using the adjoint higgs, converts these dimension 5 operators effectively into dimension 6. By explicitly computing the higgs spectrum and the resulting threshold uncertainties we show that the successful prediction of sin 2 θ W is maintained as a prediction in this scheme. It is argued that only a weak suppression of the higgsino mediated proton decay is achievable within SUSY SU (5) without fine– tuning, in contrast to a strong suppression in SUSY SO(10).
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