Modular symmetry, twisted sectors and flavour

Abstract

We investigate the implications for fermion mass models in heterotic orbifolds of the modular symmetry mixing twisted states localized at different fixed points. We show that, unlike in the case of continuous gauge symmetries, the mass eigenstates do not mix under the symmetry; thus coupling constants in the low-energy theory are invariant functions of the moduli.

Comments: 4 pages, ws-procs9x6.cls included. Contribution to conference proceedings, String Phenomenology '02, Oxford