2012/05/24 by Goran Senjanovic · 1 citation
Physics and Astronomy · #hep-ex #hep-ph
paper · pdf · doi:10.1142/s2010194512006848
To be published in the proceedings of the Scientific and Human Legacy of Julius Wess, Memorial Workshop held in Donji Milanovac, Serbia, August 2011
arxiv created 2012/05/24 · arxiv updated 2015/06/05
I review the unification of gauge couplings of strong, weak and electro-magnetic interactions. I start by recalling the history of the most important prediction of low-energy supersymmetry: the correct value of the weak mixing angle tied to a large top quark mass. I then turn to the discussion of the present day situation of the minimal supersymmetric Grand Unified Theories based on SU(5) and SO(10) groups, and I show why the minimal SU(5) is in accord with experiment. For the sake of completeness I also summarize the problems and possible solutions of the minimal ordinary SU(5). One version, based on the minimal Georgi-Glashow model, augmented by the adjoint fermion, predicts a light fermion triplet to lie below TeV or so. Its (lepton number violating) decays offer a hope of probing neutrino (Majorana) masses and mixings at the LHC.