In a certain type of Calabi-Yau superstring models it is clarified that the symmetry breaking occurs by stages at two large intermediate energy scales and that two large intermediate scales induce large Majorana-masses of righthanded neutrinos. Peculiar structure of the effective nonrenormalizable interactions is crucial in the models. In this scheme Majorana-masses possibly amount to O(10^9∼^<10>GeV) and see-saw mechanism is at work for neutrinos. Based on this scheme we propose a viable model which explains the smallness of masses for three kind of neutrinos ν_e, ν_μ and ν_τ . Special forms of the nonrenormalizable interactions can be understood as a consequence of an appropriate discrete symmetry of the compactified manifold.
雑誌名
Progress of theoretical physics
巻
92
号
1
ページ
153 - 174
発行年
1994
出版者
理論物理学刊行会
ISSN
0033-068X
書誌情報
Progress of theoretical physics. 1994, 92(1), p. 153-174.