Charm fragmentation fractions and cc cross section in p-Pb collisions at s ₍₍=5. 02 TeV

The total charm-quark production cross section per unit of rapidity d (cc) /dy, and the fragmentation fractions of charm quarks to different charm-hadron species f (c h₂), are measured for the first time in p-Pb collisions at sNN = 5. 02 TeV at midrapidity (-0. 96<y<0. 04 in the centre-of-mass frame) using data collected by ALICE at the CERN LHC. The results are obtained based on all the available measurements of prompt production of ground-state charm-hadron species: D^0, D^+, Dₛ^+, and J/ mesons, and c^+ and ₂^0 baryons. The resulting cross section is d (cc) /dy =219. 6 6. 3\; (stat. ) \;-₁₁. ₈^+10. 5\; (syst. ) \;-₂. ₉^+7. 6\; (extr. ) 5. 4\; (BR) 4. 6\; (lumi. ) 19. 5\; (rapidity shape) +15. 0\; (₂^0) mb, which is consistent with a binary scaling of pQCD calculations from pp collisions. The measured fragmentation fractions are compatible with those measured in pp collisions at s = 5. 02 and 13 TeV, showing an increase in the relative production rates of charm baryons with respect to charm mesons in pp and p-Pb collisions compared with e^+e^{-} and e^-p collisions. The pT-integrated nuclear modification factor of charm quarks, RₚPb (cc) = 0. 91 0. 04\; (stat. ) ^+0. 08-₀. ₀₉\; (syst. ) ^+0. 04-₀. ₀₃\; (extr. ) 0. 03\; (lumi. ), is found to be consistent with unity and with theoretical predictions including nuclear modifications of the parton distribution functions.