NON-UNIFIED SPARTICLE AND PARTICLE MASSES IN UNIFIED THEORIES.

Abstract

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 $\simeq 3$, partly accounting for the large $m_t /m_b$. Another gives $m_b/m_\tau$ between 2/3 and 1; this relaxes the strict bounds on the top mass and neutrino properties that come from $b$--$\tau$ unification. Still another allows $ m_s/m_\mu$ to be between 1/6 and 1 and evades the potentially problematic GUT relation of $m_s=m_\mu$. The final example has horizontal sparticle splittings in spite of the existence of horizontal symmetries.