Correlated leading baryon-antibaryon production in e⊃+e⊃- →cc̄→Λc+Λ̄c-X

We present a study of 649 ± 35 e^+e^- → cc events produced at √s ≈ 10:6 GeV containing both a Λ^+_c baryonand a Λ -_c antibaryon. The number observed is roughly 4 times that expected if the leading charmed hadron types are uncorrelated, confirming an observation by the CLEOCollaboration. We find a 2-jet topology in these events but very few additional baryons, demonstrating that the primary c and c are predominantly contained in a correlated baryon-antibaryon system. In addition to the charmed baryonswe observe on average 2:6 ± 0:2 charged intermediate mesons, predominantly pions, carrying 65% of the remaining energy.