Correlated leading baryon-antibaryon production in e+e- --> ccbar --> Lambda_c+ antiLambda_c- X

TL;DR

This study investigates correlated Lambda_c baryon-antibaryon production in electron-positron collisions at 10.6 GeV, revealing a strong correlation and a predominantly two-jet topology with minimal additional baryons.

Contribution

It provides the first detailed measurement of correlated Lambda_c baryon-antibaryon production, confirming previous observations and analyzing the event topology and energy distribution.

Findings

Observed four times more Lambda_c pairs than uncorrelated expectation.

Events predominantly exhibit a two-jet topology with few extra baryons.

Charged mesons carry 65% of the remaining energy in these events.

Abstract

We present a study of 649 \pm 35 e+e- --> ccbar events produced at sqrt{s}~10.6 GeV containing both a Lambda_c baryon and a Lambda_c antibaryon. The number observed is roughly four 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 cbar are predominantly contained in a correlated baryon-antibaryon system. In addition to the charmed baryons we observe on average 2.6 \pm 0.2 charged intermediate mesons, predominantly pions, carrying 65% of the remaining energy.