Connecting Leptonic Unitarity Triangle to Neutrino Oscillation

Understand

Leptonic unitarity triangle (LUT) provides a geometric description of CP violations in the lepton-neutrino sector and is directly measurable in principle.

• In this work, we reveal that the angles in the LUT have definite physical meaning, and demonstrate the exact connection of the LUT to neutrino oscillations.
• For the first time, we prove that these leptonic angles act as phase shifts in neutrino oscillations, by shifting \Delta m^{2}L/2E to \Delta m^{2}L/2E + \alpha, where (L, E, \alpha) denote the baseline length, neutrino energy and corresponding angle of the LUT.
• Each LUT has three independent parameters and contains only partial information of the PMNS matrix.