Article ID Journal Published Year Pages File Type
10724845 Physics Letters B 2012 5 Pages PDF
Abstract
The Daya Bay Collaboration (preprint) [1] has recently proclaimed discovery of non-zero reactor angle, θ13, sin22θ13=0.092±0.016(stat)±0.005(syst), at 5.2σ which is in conformity with the earlier observations of T2K Collaboration (2011) [2], MINOS Collaboration (2011) [3] and DOUBLE CHOOZ Collaboration (2011) [4] last year. The discovery has immense implication for exploring CP-violation in the leptonic sector. In the present work, we examine CP-violation in Majorana neutrino mass matrix, in the basis where charged lepton mass matrix is diagonal, in which the ratio of elements are equal, also, termed as Strong Scaling Ansatz (SSA). This Ansatz has been known to explain the vanishing of θ13 and predict inverted hierarchy (IH) for the neutrino masses. However, to generate a non-zero value of θ13 consistent with Daya Bay result one has to deviate from SSA. This deviation will have important implications for CP-violation in the leptonic sector and is one of the issues addressed in the present work. CP is maximally violated because, for central value of θ13 obtained from Daya Bay experiment, Dirac-type phase |δ|≈π2, 3π2 which corresponds to |JCP|≈0.03. We have, also, studied imperative implications for Majorana-type phases α, β and effective neutrino mass, Mee. The Majorana-type phases α, β are found to be sharply constrained.
Related Topics
Physical Sciences and Engineering Physics and Astronomy Nuclear and High Energy Physics
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