Impact of local and global event conditions in prompt charm hadron ratios

Abstract

Fragmentation functions extracted from electron-proton and electron-positron collisions have shown not to be able to explain prompt charm hadron ratios in proton-proton collisions at the LHC energies. New models and event generator tunes have been developed to correctly describe the data from the ALICE experiment in proton-proton collisions at different center of mass energies. In this work Pythia 8.312 is used to implement two of those models: the SC-CR and BLC-CR + Ropes. Both show a good performance to reproduce the data at \sqrt{s}} = 13 TeV in different event conditions for the ${\Lambda }_c^{+}/{\mathrm{D}}^0$, ${\Sigma }_c^{0,+,++}/{\mathrm{D}}^0$, ${\mathrm{D}}^{+}/{\mathrm{D}}^0$ and ${\mathrm{D}}^{\ast +}/{\mathrm{D}}^0$ ratios. For the particular case when the prompt charm hadrons are within jets, all the ratios show modifications relative to the case where the presence of jets is not required. A study in two different ranges of the relative transverse activity is also conducted. In this case only the baryon to meson ratios show a dependence on the underlying event activity. Results indicate that baryon and meson hadronisation are not affected in the same way by local effects or global event conditions

Comments: 13 pages, 17 figures