TeV-scale seesaw with non-negligible left-right neutrino mixings
  We suggest natural TeV-scale seesaw with non-negligible left-right neutrino mixings as preserving tiny neutrino masses. Our analysis is exhibited, without loss of generality, by taking a basis of the neutrino matrices, in which the condition to obtain the left-right mixings is clear. We also suggest a flavor symmetry as an underlying theory, which naturally realizes our setup to preserve tiny neutrino masses. Our setup can predict a magnitude of sin theta_13 in a region of 0.10 to 0.20, depending on the deviation from maximal atmospheric neutrino mixing and CP phase. We also investigate experimental constraints and phenomenology in our setup. 
Naoyuki Haba, Tomohiro Horita, Kunio Kaneta, and Yukihiro Mimura
hep-ph