Analysis of threeneutrino oscillations in the full mixing angle space.pdfVIP

Analysis of three-neutrino oscillations in the full mixing angle space D. C. Latimer and D. J. Ernst Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA (Dated: February 8, 2008) We use a model, with no CP violation, of the world’s neutrino oscillation data, excluding the LSND experiments, and search the full parameter space (0 ≤ θ12 ≤ π/2; −π/2 ≤ θ13 ≤ π/2; and 0 ≤ θ23 ≤ π/2) for the best fit values of the mixing angles and mass-squared differences. We find that the mixing angle θ13 is bounded by −0.15 θ13 0.20 with an absolute minimum at θ13 = 0.12 and a local minimum at −0.04. The importance of the negative θ13 region and this structure in the chi-square space has heretofore been overlooked because the factorization approximation commonly employed yields oscillation probabilities that are a function of sin2 θ13. PACS numbers: 14.60.-z,14.60.Pq 4 Keywords: neutrino, oscillations, three neutrinos, neutrino mixing 0 0 2 The observation of neutrino oscillations requires a fun- troduce a posteriori a mass matrix and unitary mixing c damental modification of the electroweak theory. The matrix. The standard [1] representation of the three neu- e D simplest, but not totally consistent, method for accom- trino mixing matrix is modating neutrino oscillations into the theory is to in- 3 2 4 v  c c s c s e−iδ 