CP violating phase from minimal texture neutrino mass matrix: Test of   the phase relevant to leptogenesis
  The model of neutrino mass matrix with minimal texture is now tightly constrained by experiment so that it can yield a prediction for the phase of CP violation. This phase is predicted to lie in the range $\delta_{CP}=0.77\pi - 1.24\pi$. If neutrino oscillation experiment would find the CP violation phase outside this range, this means that the minimal-texture neutrino mass matrix, the element of which is all real, fails and the neutrino mass matrix must be complex, i.e., the phase must be present that is responsible for leptogenesis. 
Masataka Fukugita, Yuya Kaneta, Yusuke Shimizu, Morimitsu Tanimoto,   and Tsutomu T. Yanagida
hep-ph