Energy and angular correlations in tau → πKν

A measurement of energy and angular correlations in the decay tau → πKν can be a source of valuable information on the pion-kaon interaction. With the assumption of a tau-ν current of V - A form and T-reversal invariance in the weak production of the pion and kaon, the correlations in the decay can reveal the relative phase for the s and p partial waves in pion-kaon scattering. The differential decay distribution for this decay is exhibited as a function of four kinematic variables and with hadronic form factors which are defined as proportional to the amplitudes for production into s and p partial waves. In experiments with limited statistics the phase difference can be determined by appropriate cuts in the data