ON THE QUESTION OF A TENSOR INTERACTION IN PI-]EV(E)GAMMA DECAY

Data from a recent experiment on pi --> ev(e)gamma appear to be in disagreement with the standard model description of this decay. The discrepancy has been interpreted as a possible indication of the presence of a tensor quark-lepton interaction. We discuss the available empirical constraints on tensor interactions, and investigate the tensor interactions arising from the exchange of spin-zero leptoquarks. We find that while the above interpretation of the discrepancy in pi-ev(e)gamma runs into difficulties, it cannot be regarded yet as ruled out.