Speaker
Description
The charm hadron production in high-energy $pp$ collisions into the forward
region ($2<\eta<5$) has been recently studied by LHCb experiment at
several centre-of-mass energies of 5, 7 and 13 TeV [1-3].
These studies were done mainly for charm mesons and there is a certain lack
of the data for baryons. Moreover, excited states were not investigated at all.
The ongoing research is devoted to the measurement of relative differential
cross sections for the production of the $\Sigma_c^{++}$, $\Sigma_c^{0}$,
$\Lambda_c(2595)^{+}$ and $\Lambda_c(2625)^{+}$ baryons with respect to their
ground state $\Lambda_c^{+}$. Decays $\Sigma_c^{++,0}
\to \Lambda_c^{+} \pi^{\pm}$ and $\Lambda_c^{*+} \to
\Lambda_c^{+} \pi^+\pi^-$ followed by
$\Lambda_c^{+} \to pK^{-}\pi^{+}$ are used for these purposes.
The studies are done with the dataset collected by LHCb at the
$\sqrt{s}_{pp}$ = 8 TeV. The obtained results will be useful for
the tuning of the Monte-Carlo generators, especially as they will shed a
light on the hadronisation process. We expect that they may help to obtain
fragmentation fractions for these excited states.
Main analysis steps are selection of the candidates including the separation
of the prompt component, correction on the detection as well as on particle
identification efficiencies. These steps will be discussed in the contribution.
1. LHCb Collaboration, Prompt charm production in $pp$ collisions at $ \sqrt{s}=7 $ TeV, Nucl. Phys. B, 871 (2013)
2. LHCb Collaboration, Measurements of prompt charm production cross-sections in $pp$ collisions at $ \sqrt{s}=13 $ TeV, JHEP 03, 159 (2016), JHEP 09, 013 (2016), JHEP 05, 074 (2017)
3. LHCb Collaboration, Measurements of prompt charm production cross-sections in pp collisions at $ \sqrt{s}=5 $ TeV, JHEP 06 147 (2017)
