Production of the charmed baryon Λ+c in π−Cu and K−Cu interactions at 230 GeV

Combined analysis of charm-quark fragmentation-fraction measurements

“…First, the selection is limited to the measurements obtained in the collisions of high energy particle beams as it assures an absence of possible matter effects and the charm quark production mechanism in these environments is well understood. The measurements of charm-hadron production in proton-meson, proton-nucleon and nucleon-nucleon collisions [38][39][40][41][42][43] were omitted as those provide results in very specific production environment and energy ranges which cannot be easily compared to the results in other experiments.…”

Effective functional form of Regge trajectories

“…For 350 GeV π − beam on emulsion the WA75 collaboration [51] finds n = 3.5 ± 0.5. In π − Cu interactions at 230 GeV the ACCMOR collaboration [52] finds n = 3.23 ± 0.29 for leading charm production (and n = 4.34 ± 0.35 for nonleading, and n = 3.74 ± 0.23 for the combined data). For 340 GeV π − beam on Si, Cu and W targets the WA82 collaboration [53] finds n = 2.9 ± 0.3.…”

Leading charm in hadron-nucleus interactions in the intrinsic charm model

“…[11]. The model [12] also correctly predicted the symmetric production of D − s and D + s mesons and Λ + c and Λ + c baryons by π − beams [7,32,42].…”

“…On the other hand, the deltafunction assumes that the charm quark coalesces with a low-x spectator sea quark or a low momentum secondary quark with little or no momentum loss [17]. This assumption is more consistent with low p T charm hadroproduction data [30,31,32] than Peterson fragmentation.…”