Radiative breaking, proton stability and the viability of no-scale supergravity models

Radiative breaking of the electro-weak symmetry is carried out in the no-scale SU(5) supergravity model where the seed of supersymmetry breaking is the universal gaugino mass m1/2. The dynamically generated superparticle spectrum is then used in the computation of the dressing loop diagrams of dimension-five operators which control proton decay. Using the theoretical assumption that the LSP is electrically neutral and that the Higgs triplet mass MH3<3MG (which corresponds to the Higgs triplet Yukawa coupling being perturbative at the GUT scale) it is shown that the no-scale model gives a p→anti νK+ decay lifetime which is in violation of the current lower limits of the Kamiokande experiment, over the entire allowed range of m1/2 and tan β for both μ>0 and μ<0 where μ is the Higgs mixing parameter. (orig.)