Theoretical Uncertainties in Proton Lifetime Estimates

We recapitulate the primary sources of theoretical uncertainties in proton lifetime estimates in renormalizable, four-dimensional and non-supersymmetric grand unifications that represent the most conservative framework in which this question may be addressed at the perturbative level. We point out that many of these uncertainties are so severe that there are only very few scenarios in which an NLO approach, as crucial as it is for a real testability of any specific model, is actually sensible. Among these, the most promising seems to be the minimal renormalizable SO(10) GUT whose high-energy gauge symmetry is spontaneously broken by the adjoint and the five-index antisymmetric irreducible representations.Comment: 6 pages, 1 figure, prepared for the proceedings of the CETUP* 2015 program (Neutrinos and Beyond Standard Model Physics session: July 6 - July 17, 2015), Lead, South Dakot

Non-unitarity effects in a realistic low-scale seesaw model

We analyze the structure of the non-unitary leptonic mixing matrix in the inverse seesaw model with heavy singlets accessible at the LHC. In this model, unlike in the usual TeV seesaw scenarios, thelow-scale right-handed neutrinos do not suffer from naturalness issues. Underlying correlations among various parameters governing the non-unitarity effects are established, which leads to a considerable improvement of the generic non-unitarity bounds. In view of this, we study the discovery potential of the non-unitarity effects at future experiments, focusing on the sensitivity limits at a neutrino factory.Comment: 6 pages, 2 figures, numerical results updated, references adde

Quark and lepton masses and mixing in SO(10) with a GUT-scale vector matter

We explore in detail the effective matter fermion mass sum-rules in a class of renormalizable SUSY SO(10) grand unified models where the quark and lepton mass and mixing patterns originate from non-decoupling effects of an extra vector matter multiplet living around the unification scale. If the renormalizable type-II contribution governed by the SU(2)_L-triplet in 54_H dominates the seesaw formula, we obtain an interesting correlation between the maximality of the atmospheric neutrino mixing and the proximity of y_s/y_b to V_cb in the quark sector.Comment: 13 pages, 1 figure, 2 tables; v2: major update, references adde