Msgut Reborn?

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We present examples of fits of fermion mass data using the 10-120- FM Higgs system in Susy SO(10) GUTs that follow the scenarioblmdoom,nmsgutI in which the 120 -plet collaborates with the 10-plet to fit the charged fermion masses while small -plet couplings enhance the Type I seesaw neutrino masses to viable values and make the fit to light fermions accurate. Restricting ourselves to the CP conserving case we use a linear perturbative technique to obtain accurate charged fermion fits (χ²tot <.2) to all the charged fermion masses and angles. The resulting fits imply Type I neutrino masses that are generically 10²- 10³ times larger than those obtained in the 10- scenario precisely because of the small coupling. Thus the difficulty of obtaining sufficiently large neutrino masses in the context of these Next to Minimal Susy GUTs is essentially removed. The remaining free parameters allow one to obtain the correct ratio of neutrino mass squared splitting and a large(θ₂₃PMNS) and small(θ₁₃PMNS) mixing angle. The θ₁₂PMNS is however small and this indicates that -as in the Type I 10- case - a fully realistic fit to the lepton mixing data also requires CP violation.