On fermion mass hierarchy from flavor-dependent Yukawas

Abstract

We discuss the fermion masses in a string-inspired scalar extension of the standard model in four stacks of intersecting D-branes with a flavor-dependent symmetry. A complex scalar field S is required to generate all fermion Yukawa couplings. The latter are successively suppressed and their magnitudes weight the scales of fermion masses and offer a partial solution to the hierarchy problem. Using the known data, we estimate the relevant scales for the model.

Modèles d’intersections des D-branes : un panorama

“…Ces champs scalaires supplémentaires S q d'origine géométrique sont bien motivés dans cette direction [20][21][22]. Phénoménologique-ment, une raison pour l'ajout de ces champs est généralement d'affecter certains termes du superpotentiel.…”

Probing new physics scale with high-energy neutrinos

“…Most of these undetermined parameters re ect our lack of understanding of avor physics [3,4]. The SM provides no explanation of why there is a mass hierarchy among the fermion masses, and with the discovery of neutrino mass, this quest has received a massive impetus towards the explanation of the existing tiny neutrino mass [5,6]. The origin of such a small mass compared with other particles that we know has remained mysterious [6,7].…”

On Neutrino Oscillations and Flavour Persistence

“…The notion of particle masses, especially for neutrino, remains an actual problem of particle physics where neutrinos have been a …eld of wide studies [1,2,3]. In the SM, neutrinos were presented as verily massless fermions, in contrast with the recent evidences of their ‡avour oscillations bringing the …rst sign of the non-zero tiny neutrino masses [4,5,6].…”