Localization of massive fermions on the baby-skyrmion branes in 6   dimensions
  We construct brane solutions in 6 dimensional Einstein-Skyrme systems. A class of baby skyrmion solutions realizes warped compactification of the extra dimensions and gravity localization on the brane for negative bulk cosmological constant. Coupling of the fermions with the brane skyrmions lead to the brane localized fermions. In terms of the level crossing picture, emergence of the massive localized modes as well as the zero mode are observed. Nonlinear nature of the skyrmions brings richer information for the fermions level structure. The level comprises doubly degenerate lowest plus single excited modes. The three generation of the fundamental fermions is based on this structure. The quark/lepton mass hierarchy is successfully obtained in terms of a slightly deformed baby-skyrmions with topological charge three. 
Yuta Kodama, Kento Kokubu, Nobuyuki Sawado