Instanton Induced Charged Fermion and Neutrino Masses in a U (3) _C × U (3) _L × U (3) _R Gauge Symmetry

Abstract

Using instanton effects, we consider a 𝑈 (3) C × 𝑈 (3) L × 𝑈 (3) R gauge symmetry obtained from intersecting D6branes. This is equivalent to the trinification model extended by the three 𝑈 (1) factors that survive as global symmetries in the low energy effective model. In the corresponding three-stack, the fermion masses are induced by the possible stringy corrections to the corresponding superpotential by using E2-instantons. Using the known data with neutrino masses 𝑚𝑣 𝜏 ∼ 1 eV, we show the magnitudes of the relevant scales.