Structure Functions in the Decay ! 0 0 Cleo Collaboration Typeset Using Revt E X 1

Using the CLEO II detector operating at the CESR e + e ? collider, we have measured the structure functions in the decay ! 0 0 , based on a sample corresponding to 4 10 6 produced-pair events. We determine the integrated structure functions, which depend only on the three pion invariant mass, as well as the structure functions diierential in the Dalitz plot. We extract model independent limits on non-axial-vector contributions from the measured structure functions as less than 16:6% of the total branching fraction, at the 95% conndence level. Separating the non-axial-vector contributions into scalar and vector contributions, we measure that scalars (vectors) contribute with less than 9:4% (7:3%) to the total branching ratio, at the 95% conndence level.