New Approach to GUTs

Abstract

We introduce a new string-inspired approach to the subject of grand unification which allows the GUT scale to be small, \lesssim 200 TeV, so that it is within the reach of {\em conceivable} laboratory accelerated colliding beam devices. The key ingredient is a novel use of the heterotic string symmetry group physics ideas to render baryon number violating effects small enough to have escaped detection to date. This part of the approach involves new unknown parameters to be tested experimentally. A possible hint at the existence of these new parameters may already exist in the EW precision data comparisons with the SM expectations.