Hadronic production of Λc from 600 GeV/c π−, Σ− and p beams

Abstract We present data from Fermilab experiment E781 (SELEX) on the hadroproduction asymmetry for Λ c − compared to Λ c + as a function of x F , and on p t 2 distributions for Λ c + . These data were measured in the same apparatus using incident π − , Σ − beams at 600 GeV/ c and proton beam at 540 GeV/ c . The asymmetry is studied as a function of x F . In the forward hemisphere with x F ⩾0.2 both baryon beams exhibit very strong preference for producing charm baryons rather than charm antibaryons, while the pion beam asymmetry is much smaller. In this energy regime the results show that beam fragments play a major role in the kinematics of Λ c formation, as suggested by the leading quark picture.