Inverted neutrino mass hierarchy and mixing in the Zee-Babu model
  We show that the neutrino mass matrix of the Zee-Babu model is able to fit the recent data on neutrino masses and mixing with non-zero $\theta_{13}$ in the inverted neutrino mass hierarchy. The results show that the Majorana phases are equal to zero and the Dirac phase ($\de$) is predicted to either $0$ or $\pi$, i. e, there is no CP violation in the Zee-Babu model at the two loop level. The effective mass governing neutrinoless double beta decay and the sum of neutrino masses are consistent with the recent analysis. 
Vo Van Vien, Hoang Ngoc Long and Pham Ngoc Thu
hep-ph