Status of the superworld from theory to experiment

Abstract

Among the most outstanding conceptual developments in particle physics we have: the unification of all particle interactions at very-high energies (Grand Unification), the fermion-boson symmetry (Supersymmetry), the non-point-like structure of elementary particles (String theory), and the understanding that all dynamical quantities (gauge couplings, masses, Yukawa couplings) run with energy (Renormalization Group Equations). The goal is to make use of these great developments to construct a theory which embraces all fundamental forces of Nature, including gravity. In this review we address this problem and its possible implications for physics in the energy range where our experimental facilities operate. We show that what is required are not qualitative arguments but a set of detailed calculations with definite predictions. This is why we have chosen two specific Supergravity models: SU(5) and SU(5)× U(1). One as representative of Field Theory, the other of String Theory. This kind of model-building at the Planck scale seems to tell us that new physics beyond the Standard Model could be near the Fermi scale. Therefore detailed calculations for existing facilities (Tevatron, LEP I-II, HERA, Gran Sasso, Super Kamiokande, Dumand, Amanda, etc.) are a definite way to put string theory - i.e., the existence of the Superworld - under experimental test, now.