Radiative corrections to sfermion mass splittings

We study the one-loop radiative corrections to the SU(2)-breaking mass splittings between sfermions in SU(2) doublets in the minimal supersymmetric standard model. At the tree level, the differences of the mass squared mf1L2-mf2L2 of SU(2) doublet sfermions (f1,f2)L in the first two generations are determined by tanβ, and are universal to sleptons and squarks. The radiative correction, however, breaks this relation. The typical deviation from the universality between sleptons and squarks is within ±0.05 in terms of the open-quote open-quote effective cos2β.close-quote close-quote We also study the SUSY parameter dependence of the deviation. For very heavy sfermions, the relative corrections become large. copyright 1996 The American Physical Society