A new neutrino mass sum rule from inverse seesaw
  A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). One of these implies in a lower bound on the effective neutrinoless double beta mass parameter, even for normal hierarchy neutrinos. Here we propose a new model based on the S4 flavor symmetry that leads to the new neutrino mass sum-rule and discuss how to generate a nonzero value for the reactor mixing angle indicated by recent experiments, and the resulting correlation with the solar mixing angle. 
L. Dorame, S. Morisi, E. Peinado, Alma D. Rojas, J. W. F. Valle
hep-ph hep-ex nucl-ex