; Luo, Shu
; Xing, Zhi-Zhong
; Zhou, Shun] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
Article; Proceedings Paper
A natural extension of the standard model to accommodate massive neutrinosis to introduce one Higgs triplet and three right-handed Majorana neutrinos, leading to a 6 x 6 neutrino mass matrix. We show that three light Majorana neutrinos (i.e., the mass eigenstates of v(e), v(mu) and v(tau)) are exactly massless, if and only if M-L = (MDMR-1MDT) exactly holds in this seesaw model. We propose three simple Type-II seesaw scenarios with broken A(4) x U(1)(X) flavor symmetry to interpret the observed neutrino mass spectrum and neutrino mixing pattern. Such a TeV-scale neutrino model can be tested in two complementary ways: (1) searching for possible collider signatures of lepton number violation induced by the right-handed Majorana neutrino sand doubly-charged Higgs particles; and (2) searching for possible consequences of unitarity violation of the 3 x 3 neutrino mixing matrix in the future long-baseline neutrino oscillation experiments.