CP Violation, Cosmological Baryon Asymmetry and Neutrino Masses — The Effect of Intermediate Mass Scales

Abstract

The question whether the 102 – 1015 GeV big desert is completely wild or contains some oases at intermediate mass scales (IMS) is still open. As we are denied any direct verification (at least for IMS some orders of magnitude away from MW), it behooves us to sharpen any possible motivation and/or consequences of such IMS. Apart from the “classical” emotional (aesthetical) repulsion for a desert which does not present any analog with previous physics, some interest in IMS has been renewed by new trends in particle physics: i) technicolour (including supercolour or technicolour/supersymmetric technicolour scenarios) and the composite models introduce a new fundamental strong interaction, whose scale must be in the TeV region to reproduce the phenomenological weak interaction scale MW (no matter how poor, they represent the only candidates for a dynamical understanding of MW); ii) some standard problems of the fruitful particle physics-cosmology marriage could require a prolonged first order phase transition, thus introducing some physical scale between the grand unification mass (MQU) and MW