Gaussian Froggatt-Nielsen mechanism on magnetized orbifolds
  We study the structure of Yukawa matrices derived from the supersymmetric Yang-Mills theory on magnetized orbifolds, which can realize the observed quark and charged lepton mass ratios as well as the CKM mixing angles, even with a small number of tunable parameters and without any critical fine-tuning. As a reason behind this, we find that the obtained Yukawa matrices possess a Froggatt-Nielsen like structure with Gaussian hierarchies, which provides a suitable texture for them favored by the experimental data. 
Hiroyuki Abe, Tatsuo Kobayashi, Keigo Sumita and Yoshiyuki Tatsuta
hep-ph hep-th