Λc+ production and baryon-to-meson ratios in pp and p-Pb collisions at sNN = 5.02 TeV at the LHC

The prompt production of the charm baryon ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}$ and the ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}/{D}^{0}$ production ratios were measured at midrapidity with the ALICE detector in $pp$ and $p$-Pb collisions at $\sqrt{{s}_{\mathrm{NN}}}=5.02\text{ }\text{ }\mathrm{TeV}$. These new measurements show a clear decrease of the ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}/{D}^{0}$ ratio with increasing transverse momentum (${p}_{T}$) in both collision systems in the range $2<{p}_{T}<12\text{ }\text{ }\mathrm{GeV}/c$, exhibiting similarities with the light-flavor baryon-to-meson ratios $p/\ensuremath{\pi}$ and $\mathrm{\ensuremath{\Lambda}}/{K}_{S}^{0}$. At low ${p}_{T}$, predictions that include additional color-reconnection mechanisms beyond the leading-color approximation, assume the existence of additional higher-mass charm-baryon states, or include hadronization via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in ${e}^{+}{e}^{\ensuremath{-}}$ and ${e}^{\ensuremath{-}}p$ collisions significantly underestimate the data. The results presented in this Letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.