The 8th Asian Triangle Heavy-Ion Conference (ATHIC2021)

Charm-baryon production and fragmentation fractions in pp collisions with ALICE

7 Nov 2021, 13:47

17m

Room 107 (60th Anniversary Hall , Inha Univ. Incheon, South Korea)

Experiment Contributed Session 3

Speaker

Jinjoo Seo (Inha University (KR))

Description

The production cross sections of open heavy-flavour hadrons can be obtained by the collinear factorisation approach of QCD, by means of a convolution of the initial parton distribution functions of the incoming partons, the perturbative QCD partonic cross section, and the fragmentation functions in ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$, ep collisions. Recent measurements of charm-baryon production at midrapidity performed by ALICE in small collision systems show a baryon-to-meson ratio significantly higher than in ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ collisions. This enhancement cannot be explained by model calculations considering charm fragmentation functions obtained in \ee collisions and suggests that the charm fragmentation is not universal across collision systems. Therefore, measurements of charm-baryon production are crucial to investigate the hadronisation mechanism of charm quarks. Measurements of charm-baryon production in p--Pb collisions also provide information about Cold Nuclear Matter (CNM), helping to understand the possible presence of collective effects or the modification of hadronisation mechanisms.

In this contribution, the latest measurements of ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$, ${\mathrm{\Xi }}_{\mathrm{c}}^{0,+}$, ${\mathrm{\Sigma }}_{\mathrm{c}}^{0,++}$, and the first measurement of ${\mathrm{\Omega }}_{\mathrm{c}}^0$ baryons performed with the ALICE detector at midrapidity in pp collisions at $\sqrt{s}=5.02$ and $13\mathrm{T}\mathrm{e}\mathrm{V}$ are presented. Also, the first measurements of the total charm cross section at midrapidity and the fragmentation fractions at midrapidity in pp collisions at the LHC including the charm baryons are discussed. In addition, the ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$ measurement down to $p_{\mathrm{T}}=0$ in p--Pb collisions will be discussed.

Presentation materials

211107_jj_ATHIC2021_v3.pdf