Combining accelerator and reactor measurements of θ 13: the first result

The lepton mixing angle θ 13, the only unknown angle in the standard three-flavor neutrino mixing scheme, is finally measured by the recent reactor and accelerator neutrino experiments. We perform a combined analysis of the data coming from T2K, MINOS, Double Chooz, Daya Bay and RENO experiments and find sin2 2θ 13 = 0.096 ± 0.013(±0.040) at 1 σ (3 σ) CL and that the hypothesis θ 13 = 0 is now rejected at a significance level of 7.7 σ. We also discuss the near future expectation on the precision of the θ 13 determination by using expected data from these ongoing experiments.