Search for D{sup +}{sub -} {yields} {pi}{sup +-}{mu}{sup +-}{mu} and D{sup +-} {yields} {pi}{sup +-}e{sup +-}e{sup -+}

The authors report on the search for the Flavor Changing Neutral Current (FCNC) decay modes D{sup {+-}} {yields} {pi}{sup {+-}}{mu}{sup {+-}}{mu}{sup -+} and D{sup {+-}} {yields} {pi}{sup {+-}}e{sup {+-}}e{sup -+} based on 100% of the reconstructed charm sample from Fermilab experiment E791. Since the Standard Model predicts FCNC decay modes to be forbidden in first order, a positive signal would indicate new physics. The E791 data set offers greater sensitivity than previous searches.