Λ_c⁺ Production and Baryon-to-Meson Ratios in pp and p-Pb Collisions at √s_NN =5.02 TeV at the LHC

Summary, in English

The prompt production of the charm baryon Λ+c and the Λ+c/D0 production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at √sNN=5.02 TeV. These new measurements show a clear decrease of the Λ+c/D0 ratio with increasing transverse momentum (pT) in both collision systems in the range 2<pT<12 GeV/c, exhibiting similarities with the light-flavor baryon-to-meson ratios p/π and Λ/K0S. At low pT, predictions that include additional color-reconnection mechanisms beyond the leading-color approximation, assume the existence of additional higher-mass charm-baryon states, or include hadronization via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e+e− and e−p collisions significantly underestimate the data. The results presented in this Letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.

• Author: S Acharya; Jonatan Adolfsson; Sumit Basu; Peter Christiansen; Oliver Matonoha; Adrian Nassirpour; Alice Ohlson; Anders Oskarsson; Tuva Richert; Omar Vazquez Rueda; David Silvermyr; N Zurlo
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2021
• Language: English
• Publication/Series: Physical Review Letters
• Volume: 127
• Issue: 20
• Links: http://dx.doi.org/10.1103/PhysRevLett.127.202301
• Document type: Journal article
• Publisher: American Physical Society
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1079-7114