Non-unified sparticle and particle masses in unified theories

We give examples of minimal extensions of the simplest SU(5) SUSY-GUT in which all squarks and sleptons of a family have different tree level masses at the unification scale. This phenomenon is general; it occurs when the quarks and leptons are the light remnants of a theory which contains extra heavy families at the unification scale. The examples have interesting relations between Yukawa couplings: In one model the ratio of the top to bottom Yukawas is as large as ∼- 3, partly accounting for the large mtmb. Another gives mbmτ between 23 and 1; this relaxes the strict bounds on the top mass and neutrino properties that come from b−τ unification. Still another allows msmμ to be between 16 and 1 and evades the potentially problematic GUT relation of ms = mμ. The final example has horizontal sparticle splittings in spite of the existence of horizontal symmetries.