Abstract :
Under the assumption that CP violation is caused by exchange of a new boson, we propose to measure the magnitudes and CP violating phases of the coupling constants of this boson to five different vertices in tau decay. This can be accomplished by studying the decays of polarized tau leptons produced at an e+e− collider whose beams are polarized. We point out that CP violation in the leptonic sector tests most directly the assumption that the imaginary numbers in the mass matrix is the sole cause of CP violation.