Determination of an upper limit on D{sup 0} - D{sup 0} mixing

An upper limit on D{sup 0} - {bar D}{sup 0} mixing is presented using approximately 3fb{sup {minus}1} of data recorded by the CLEO II detector at the Cornell Electron Storage Ring, CESR. The measurement is determined using the sign correlation between the charged lepton from semileptonic D{sup 0} decay and the soft pion from D{sup *+} {yields} D{sup 0}{pi}{sup +}.