Fitting fermion masses and mixings in F-theory GUTs

We analyse the structure of yukawa couplings in local su(5) f-theory models with e 7 enhancement. these models are the minimal setting in which the whole flavour structure for the mssm charged fermions is encoded in a small region of the entire compactification space. in this setup the e 7 symmetry is broken down to su(5) by means of a 7-brane t-brane background, and further to the mssm gauge group by means of a hypercharge flux that also implements doublet-triplet splitting. at tree-level only one family of quarks and charged leptons is massive, while the other two obtain hierarchically smaller masses when stringy non-perturbative effects are taken into account. we find that there is a unique e 7 model with such hierarchical flavour structure. the relative simplicity of the model allows to perform the computation of yukawa couplings for a region of its parameter space wider than previous attempts, obtaining realistic fermion masses and mixings for large parameter regions. our results are also valid for local models with e 8 enhancement, pointing towards a universal structure to describe realistic fermion masses within this framework.