Instanton-induced processes. An overview

A first part of this review is devoted to a summary of our extensive studies of the discovery potential for instanton (I)-induced, deep-inelastic processes at HERA. Included are some key issues about I-perturbation theory, an exploitation of crucial lattice constraints and a status report about the recent I-search results by the HERA collaborations H1 and ZEUS in relation to our predictions. Next follows a brief outline of an ongoing project concerning a broad exploration of the discovery potential for hard instanton processes at the LHC. I then turn to an overview of our work on high-energy processes, involving larger-sized instantons. I shall mainly focus on the phenomenon of saturation at small Bjorken-x from an instanton perspective. In such a framework, the saturation scale is associated with the conspicuous average instanton size, left angle ρ right angle ∝ 0.5 fm, as known from lattice simulations. A further main result is the intriguing identification of the ''Colour Glass Condensate'' with the QCD sphaleron state. (orig.)