Determination of the Third Neutrino-Mixing Angle theta_(13) and its Implications

Till 2010 we had three unknown parameters of neutrino oscillation: the third mixing angle {\\theta}_(13), the sign of the larger mass difference {\\Delta} m^(2)_(31) and the CP violating phase {\\delta}. Thanks to a number of consistent experimental results since then, culminating in the recent Daya Bay reactor neutrino data, we have a definitive determination of {\\theta}_(13) now. Moreover its measured value, sin^(2)_(2 {\\theta}_(13)) = 0.1, is close to its earlier upper limit. This has promising implications for the determination of the two remaining unknown parameters from the present and proposed accelerator neutrino experiments in the foreseeable future. This talk presents a pedagogical review of these profound developments for the wider community of young physicists. including students.