Bounds on the neutrino mixing angles and CP phase for an SO(10) model with lopsided mass matrices -: art. no. 013001

The bounds on the neutrino mixing angles and CP Dirac phase for an SO(10) model with lopsided mass matrices, arising from the presence of 16(H) and 16(H) Higgs representations, are studied by variation of the one real and three unknown complex input parameters for the right-handed Majorana neutrino mass matrix. The scatter plots obtained favor nearly maximal atmospheric neutrino mixing, while the reactor neutrino mixing lies in the range 10(-5) less than or similar to sin(2)theta(13) less than or similar to 1 x 10(-2) with values greater than 10(-3) most densely populated. A rather compelling scenario within the model follows, if we restrict the three unknown complex parameters to their imaginary axes and set two of them equal. We then find the scatter plots are reduced to narrow bands, as the mixing angles and CP phase become highly correlated and predictive. The bounds on the mixing angles and phase then become 0.45 less than or similar to sin(2)theta(23) less than or similar to 0.55, 0.38 less than or similar to tan(2)theta(12) less than or similar to 0.50, 0.002 less than or similar to sin(2)theta(13) less than or similar to 0.003, and 60 degrees less than or similar to +/-delta(CP) less than or similar to 85 degrees. Moreover, successful leptogenesis and subsequent baryogenesis are also obtained, with eta(B) increasing from (2.7 to 6.3) x 10(-10) as sin(2)theta(23) increases from 0.45 to 0.55.