Explicit rephasing to Kobayashi–Maskawa representation and fundamental phase structure of CP violation

In this letter, we construct an explicit rephasing transformation that converts an arbitrary unitary matrix into the Kobayashi–Maskawa (KM) parameterization and identify all independent CP phases in the mixing matrix as the arguments of its matrix elements. Furthermore, by applying this rephasing transformation to the fermion diagonalization matrices Uν, e, we show that the Majorana phases are represented by fermion-specific phases δ ν , eKM and their relative phases. In particular, by neglecting the 3-1 elements U₃₁ν ,e of the diagonalization matrices for the two fermions, the KM phase δKM is concisely expressed as δ KM = [1 + (Ue *₂₁ Uν₂₁ / Ue *₁₁ Uν₁₁ ) ] + [ - U₃₂e * U₃₂ν / Ue *₂₂ Uν₂₂ ] by fermion-specific rephasing invariants representing two relative phases.