The Breaking $\mu \leftrightarrow \tau$ Symmetry through the ${\mathbf{Q}}_6$ Flavour Group

In a supersymmetric scenario, we study masses and mixings for leptons through the ${\mathbf{Q}}_6$ flavour symmetry. In the simplest case, the ${\mathbf{M}}_{\nu }$ effective neutrino mass matrix, that comes from the type I see-saw mechanism, breaks the $\mu \leftrightarrow \tau$ interchange symmetry. As consequence, the reactor and atmospheric angles deviate from $0^{\circ }$ and ${45}^{\circ }$, respectively. At first glance, the model might accommodate very well the reactor and atmospheric angles in good agreement with the experimental data.