1999/12/26 by Kevin Cahill, Cahill, Kevin
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/9912508
13 pages, 2 figures; CP phase fixed; new figure
arxiv created 2000/06/19 · arxiv updated 2009/11/30
Neutrino masses and mixings are analyzed in terms of left-handed fields and a 6x6 complex symmetric mass matrix whose singular values are the neutrino masses. An angle thetanu characterizes the kind of the neutrinos, with thetanu=0 for Dirac neutrinos and thetanu=pi/2 for Majorana neutrinos. At thetanu = 0 baryon-minus-lepton number is conserved. If thetanu is approximately zero, the six neutrino masses coalesce into three nearly degenerate pairs. Thus the tiny mass differences exhibited in the solar and atmospheric neutrino experiments are naturally explained by the approximate conservation of B-L. Neutrinos are nearly Dirac fermions. This B-L model leads to these predictions: neutrinos oscillate mainly between flavor eigenfields and sterile eigenfields, and so the appearance of neutrinos and antineutrinos is suppressed; neutrinos may well be of cosmological importance; in principle the disappearance of the tau neutrino should be observable; and neutrinoless double-beta decay is suppressed by an extra factor of 10^(-5) and so will not be seen in the Heidelberg/Moscow, IGEX, GENIUS, or CUORE experiments.