Constraining hadronization mechanisms with ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$/D${}^0$ production ratios in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV

Abstract

The production of prompt ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$ baryons at midrapidity ($|y|<0.5$) was measured in central (0-10%) and mid-central (30-50%) Pb-Pb collisions at the center-of-mass energy per nucleon-nucleon pair $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV with the ALICE detector. The results are more precise, more differential in centrality, and reach much lower transverse momentum ($p_{\mathrm{T}}=1$ GeV/$c$) with respect to previous measurements performed by the ALICE, STAR, and CMS Collaborations in nucleus-nucleus collisions, allowing for an extrapolation down to $p_{\mathrm{T}}=0$. The $p_{\mathrm{T}}$-differential ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$/D${}^0$ production ratio is enhanced with respect to the pp measurement for $4<p_{\mathrm{T}}<8$ GeV/$c$ by 3.7 standard deviations ($\sigma$), while the $p_{\mathrm{T}}$-integrated ratios are compatible within 1$\sigma$. The observed trend is similar to that observed in the strange sector for the $\Lambda /$K${}_{\mathrm{S}}^0$ ratio. Model calculations including coalescence or statistical hadronization for charm-hadron formation are compared with the data.

24 pages, 3 captioned figures + 3 captioned figures in appendix, 1 table, authors from page 18, published version, figures at http://alice-publications.web.cern.ch/node/7614