The $p_T$-differential production cross sections of prompt $D^0$, ${\mathrm{\Lambda }}_c^{+}$, and ${\mathrm{\Sigma }}_c^{0,++}(2455)$ charmed hadrons are measured at midrapidity ($|y|<0.5$) in $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$. This is the first measurement of ${\mathrm{\Sigma }}_c^{0,++}$ production in hadronic collisions. Assuming the same production yield for the three ${\mathrm{\Sigma }}_c^{0,+,++}$ isospin states, the baryon-to-meson cross section ratios ${\mathrm{\Sigma }}_c^{0,+,++}/D^0$ and ${\mathrm{\Lambda }}_c^{+}/D^0$ are calculated in the transverse momentum ($p_T$) intervals $2<p_T<12$ and $1<p_T<24\mathrm{GeV}/c$. Values significantly larger than in $e^{+}{e}^{-}$ collisions are observed, indicating for the first time that baryon enhancement in hadronic collisions also extends to the ${\mathrm{\Sigma }}_c$. The feed-down contribution to ${\mathrm{\Lambda }}_c^{+}$ production from ${\mathrm{\Sigma }}_c^{0,+,++}$ is also reported and is found to be larger than in $e^{+}{e}^{-}$ collisions. The data are compared with predictions from event generators and other phenomenological models, providing a sensitive test of the different charm-hadronization mechanisms implemented in the models.

• Received 25 August 2021
• Revised 9 November 2021
• Accepted 24 November 2021

DOI:https://doi.org/10.1103/PhysRevLett.128.012001

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