CONDITIONS ON SUPERSYMMETRY SOFT-BREAKING TERMS FROM GUTS

We study the effect of integrating out the heavy fields in a supersymm etric GUT which does not contain small mass parameters in the limit of exact supersymmetry. The trilinear (A) and bilinear (B) coefficients of the supersymmetry soft-breaking terms of the low-energy effective t heory are related in a simple and model-independent way to those of th e underlying theory. From these relations, we obtain the bound Absolut e value of B greater-than-or-equal-to 2, which, together with the requ irements of stability of the potential and electroweak symmetry breaki ng, imposes severe constraints on the space of allowed supersymmetric parameters. In models based on supergravity with a flat Kahler metric, we obtain B = 2, instead of the relation B = A - 1 usually used in ph enomenological applications. The low-energy theory contains also a sup ersymmetric mass term mu for the two Higgs doublets, which is of the o rder of the supersymmetry-breaking scale.