2004/10/31 by Ilja Dorsner, Pavel Fileviez Perez · 1 citation
Physics and Astronomy · #hep-ph #hep-ex #hep-th
paper · pdf · doi:10.1016/j.physletb.2005.08.039
published as Phys.Lett.B625:88-95,2005 · 13 pages, 2 figures. Few corrections, new references
arxiv created 2005/07/21 · arxiv updated 2009/12/01
We investigate model independent upper bounds on total proton lifetime in the context of Grand Unified Theories with the Standard Model matter content. We find them to be τp ≤ 1.5+0.5-0.3 × 1039 \frac(MX/1016 \textrmGeV)4αGUT2 (0.003 \textrmGeV3 / α)2 \textrmyears and τp ≤ 7.1+0.0-0.0 × 1036 \frac(MX/1016 \textrmGeV)4αGUT2 (0.003 \textrmGeV3 / α)2 \textrmyears in the Majorana and Dirac neutrino case, respectively. These bounds, in conjunction with experimental limits, put lower limit on the mass MX of gauge bosons responsible for the proton and bound-neutron decay processes. For central values of relevant input parameters we obtain MX ≥ 4.3 × 1014 √αGUT \textrmGeV. Our result implies that a large class of non-supersymmetric Grand Unified models, with typical values αGUT ∼ 1/39, still satisfies experimental constraints on proton lifetime. Our result is independent on any CP violating phase and the only significant source of uncertainty is associated with imprecise knowledge of α--the nucleon decay matrix element.