Testing non-supersymmetric SU(5) unification

by Ilja Dorsner (ICTP, Trieste)

Friday 2 Sept 2005, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

I present predictions and discuss possible experimental signatures of a minimal realistic non-supersymmetric SU(5) grand unified theory. To accomplish unification and generate neutrino mass, only one extra Higgs representation - a 15 of SU(5) - is introduced besides the particle content of the minimal Georgi-Glashow scenario. As I will argue, generic prediction of this setup is a set of rather light scalar leptoquarks. In the case of the most natural implementation of the type II see-saw mechanism, their mass is in the phenomenologically interesting region (O(10² - 10³) GeV). As such, the scenario has a potential to be tested at the next generation of collider experiments, particularly at the Large Hadron Collider (LHC) at CERN. The presence of the 15 generates additional contributions to proton decay which, for light scalar leptoquarks, can be more important than the usual gauge d = 6 ones. I exhaustively study both and show that the scenario is not excluded but nicely constrained by current experimental bounds on nucleon lifetimes.