@article{56a6521ce8d74ced9cf998fb647c8266,
title = "Neutrino masses in the minimal O(10) theory",
abstract = "Neutrino masses are discussed in the context of the O(10) grand unified theory. In the {"}minimal{"} form of this theory, with minimal Higgs and fermion content, the right-handed neutrinos acquire masses at the two loop level. The left-handed neutrino masses are correspondingly larger by a factor roughly ( α π)-2 than they would be if the right-handed neutrino could acquire mass at the tree level. In the simplest form of this theory, the neutrino mass matrix is proportional to the up quark mass matrix, and the neutrino mixing angles equal the usual Cabibbo angles. The neutrino masses will be roughly in the range 100±2 eV depending on the strength of O(10) symmetry breaking, and on certain unknown ratios of masses and couplings of superheavy particles.",
author = "Edward Witten",
note = "Funding Information: In the simplest grand unified model, the SU(5) model \[1\],t his does not occur, because there are no right-handed neutrinos that could combine with the left-handed neutrinos to form a massive Dirac fermion, and a Majorana mass term for the left-handed neutrino is prevented by the exact conservation of baryon minus lepton number. This paper will be devoted to a few remarks about neutrino masses in the next simplest model, the O(10) model \[2\]w, hich unites the fermions of each {"}generation{"} very elegantly. The O(10) model does contain right-handed neutrinos, and they raise an apparent difficulty. Unless eliminated in some way, the right-handed neutrinos will combine with the left-handed neutrinos to form Dirac fermions with masses comparable to the usual quark and lepton masses. Recently, it has been pointed out \[3\]t hat this can be avoided if the right-handed neutrino receives a large Majorana mass. (A Majorana mass term is simply an This research is supported in part by the National Science Foundation under Grant No. PHY77-22864.",
year = "1980",
month = mar,
day = "24",
doi = "10.1016/0370-2693(80)90666-8",
language = "English (US)",
volume = "91",
pages = "81--84",
journal = "Physics Letters B",
issn = "0370-2693",
publisher = "Elsevier B.V.",
number = "1",
}