Phenomenology of future neutrino experiments with large θ13

The question “how small is the lepton mixing angle θ13?” had a convincing answer in a surprisingly short time, θ13≃9°, a large value comparable to the Chooz limit. It defines a new epoch in the program of determining the lepton mixing parameters, opening the door to search for lepton CP violation of the Kobayashi-Maskawa-type. I discuss influences of the large value of θ13 to search for CP violation and determination of the neutrino mass hierarchy, the remaining unknowns in the standard three-flavor mixing scheme of neutrinos. I emphasize the following two points: (1) Large θ13 makes determination of the mass hierarchy easier. It stimulates to invent new ideas and necessitates quantitative reexamination of practical ways to explore it. (2) However, large θ13 does not quite make CP measurement easier so that we do need a “guaranteeing machine” to measure CP phase δ.