Correlated leading baryon-antibaryon production in e+e−→c¯c→Λ+c¯¯¯Λ−cX

Abstract

We present a study of 649 ± 35 e + e − → c ¯ c events produced at √ s ≈ 10.6 GeV containing both a Λ + c baryon and 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 CLEO Collaboration. 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 baryons we observe on average 2.6 ± 0.2 charged intermediate mesons, predominantly pions, carrying 65% of the remaining energy.