Charm-quark fragmentation fractions and production cross section at midrapidity in pp collisions at the LHC

0553658 - ÚJF 2023 RIV US eng J - Journal Article
Acharya, S. - Adamová, Dagmar - Bielčík, J. - Bielčíková, Jana - Broz, M. - Contreras, J. G. - Herman, T. - Horák, D. - Isakov, Artem - Kotliarov, Artem - Křížek, Filip - Křížková Gajdošová, K. - Kushpil, Svetlana - Lavička, R. - Mareš, Jiří A. - Petráček, V. - Šafařík, K. - Šumbera, Michal - Torres, S. R. - Trzeciak, B. A. - Závada, Petr … Total 1017 authors
Charm-quark fragmentation fractions and production cross section at midrapidity in pp collisions at the LHC.
Physical Review D. Roč. 105, č. 1 (2022), č. článku L011103. ISSN 2470-0010. E-ISSN 2470-0029
R&D Projects: GA MŠMT(CZ) LTT17018
Research Infrastructure: CERN-CZ II - 90104
Institutional support: RVO:68378271 ; RVO:61389005
Keywords : ALICE collaboration * heavy ion collisions (experiment)
OECD category: Nuclear physics; Particles and field physics (FZU-D)
Impact factor: 5, year: 2022
Method of publishing: Open access
https://doi.org/10.1103/PhysRevD.105.L011103

Recent p(T)-integrated cross-section measurements of the ground-state charm mesons and baryons, D-0, D+, D-s(+), Lambda(+)(c), and Xi(0)(c) are used to evaluate the charm fragmentation fractions and production cross section per unit of rapidity at midrapidity (vertical bar y vertical bar < 0.5), in pp collisions at root s = 5.02 TeV at the LHC. The latter is d sigma(c<(c)over) (bar>)/dy vertical bar(vertical bar y vertical bar<0.5) = 1165 +/- 44(stat)(-101)(+131) (syst) mu b. These measurements were obtained for the first time in hadronic collisions at the LHC, including the charm baryon states, recently measured by ALICE at midrapidity. The charm fragmentation fractions differ significantly from the values measured in e(+)e(-) and ep collisions, providing evidence of the dependence of the parton-to-hadron fragmentation fractions on the collision system, indicating that the assumption of their universality is not supported by the measured cross sections. An increase of a factor of about 3.3 for the fragmentation fraction for the Lambda(+)(c) with a significance of 5 sigma between the values obtained in pp collisions and those obtained in e(+)e(-) (ep) collisions is reported. The fragmentation fraction for the Xi(0)(c) was obtained for the first time in any collision system. The measured fragmentation fractions were used to update the c (c) over bar cross sections per unit of rapidity at vertical bar y vertical bar < 0.5 at root s = 2.76 and 7 TeV, which are about 40% higher than the previously published results. The data were compared with perturbative-QCD calculations and lie at the upper edge of the theoretical bands.
Permanent Link: http://hdl.handle.net/11104/0328408