Measurement of Prompt D$^{0}$, $\Lambda_{c}^{+}$, and $\Sigma_{c}^{0,++}$(2455) Production in Proton–Proton Collisions at $\sqrt s$ = 13  TeV

The collaboration
Phys.Rev.Lett. 128 (2022) 012001, 2022.

Abstract
The $p_{\rm T}$-differential production cross sections of prompt D$^{0}$, $\Lambda_{\rm c}^{+}$, and $\Sigma_{\rm c}^{0,++}(2455)$ charmed hadrons are measured at midrapidity ($|y| < 0.5$) in pp collisions at $\sqrt{s} = 13$ TeV. This is the first measurement of $\Sigma_{\rm c}^{0,++}$ production in hadronic collisions. Assuming the same production yield for the three $\Sigma_{\rm c}^{0,+,++}$ isospin states, the baryon-to-meson cross section ratios $\Sigma_{\rm c}^{0,+,++}/{\rm D}^{0}$ and $\Lambda_{\rm c}^{+}/{\rm D}^{0}$ are calculated in the transverse momentum ($p_{\rm T}$) intervals $2 < p_{\rm T} < 12$ GeV/$c$ and $1 < p_{\rm T} < 24$ 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 $\Sigma_{\rm c}$. The feed-down contribution to $\Lambda_{\rm c}^{+}$ production from $\Sigma_{\rm c}^{0,+,++}$ 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-hadronisation mechanisms implemented in the models.

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Data from Figure 1 (upper right), page 4

10.17182/hepdata.127976.v1/t1

$p_\mathrm{T}$-differential cross section of prompt $D^0$ in pp collisions at $\sqrt{s}$ = 13 TeV

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Data from Figure 1 (upper right), page 4

10.17182/hepdata.127976.v1/t2

$p_\mathrm{T}$-differential cross section of prompt $\Lambda_c^+$ in pp collisions at $\sqrt{s}$ = 13 TeV

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Data from Figure 1 (upper right), page 4

10.17182/hepdata.127976.v1/t3

$p_\mathrm{T}$-differential cross section of prompt $\Sigma_c^{0,++}$ in pp collisions at $\sqrt{s}$ = 13 TeV

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Data from Figure 1 (upper right), page 4

10.17182/hepdata.127976.v1/t4

$3/2 \cdot p_\mathrm{T}$-differential cross section of prompt $\Lambda_c^+$ from $\Sigma_c^{++}$ in pp collisions at $\sqrt{s}$ = 13 TeV

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Data from Figure 2 (upper left), page 6

10.17182/hepdata.127976.v1/t5

Prompt-charm-hadron cross-section ratio $\Lambda_c^+/D^0$ in pp collisions at $\sqrt{s} = 13$ TeV

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Data from Figure 2 (upper middle), page 6

10.17182/hepdata.127976.v1/t6

Prompt-charm-hadron cross-section ratio $\Sigma_c^{0,+,++}/D^0$ in pp collisions at $\sqrt{s} = 13$ TeV

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Data from Figure 2 (upper right), page 6

10.17182/hepdata.127976.v1/t7

Prompt-charm-hadron cross-section ratio $\Lambda_c^+ \leftarrow \Sigma_c^{0,+,++}/\Lambda_c^+$ in pp collisions at $\sqrt{s} = 13$ TeV