Evidence for leading particle effects in charm fragmentation from neutrino data

Abstract

Recent data of the CERN-Dortmund-Heidelberg-Saclay collaboration on opposite sign dimuon events produced in neutrino interactions are shown to require a fragmentation function D( z) for charmed quarks non-negligible near z = 1, in contrast with the general current belief. Although the published data already suggest that the gross features of D( z) are to be described by a constant or slowly rising (near z = 1) behaviour, we find that a much more decisive test would be provided by the E + (E H + E +) distribution, where E + and E H are the energies of positive muon and of the hadron shower, respectively.