Δ(54) flavor phenomenology and strings

Δ(54) can serve as a flavor symmetry in particle physics, but remains almost unexplored. we show that in a classification of semi-realistic ℤ 3 × ℤ 3 heterotic string orbifolds, δ(54) turns out to be the most natural flavor symmetry, providing additional motivation for its study. we revisit its phenomenological potential from a low-energy perspective and subject to the constraints of string models. we find a model with δ(54) arising from heterotic orbifolds that leads to the gatto-sartori-tonin relation for quarks and charged-leptons. additionally, in the neutrino sector, it leads to a normal hierarchy for neutrino masses and a correlation between the reactor and the atmospheric mixing angles, the latter taking values in the second octant and being compatible at three sigmas with experimental data.