JOURNAL OF HIGH ENERGY PHYSICS, cilt.2025, sa.12, 2025 (SCI-Expanded, Scopus)
The first measurement at midrapidity (vertical bar y vertical bar < 0.5) of the production yield of the strange-charm baryons Xi(+)(c) and Xi(0)(c) as a function of transverse momentum (p(T)) in different charged-particle multiplicity classes in proton-proton collisions at root s = 13TeV with the ALICE experiment at the LHC is reported. The Xi(+)(c) baryon is reconstructed via the Xi(+)(c) -> Xi(-) pi(+)pi(+) decay channel in the range 4 < p(T) < 12 GeV/c, while the Xi(0)(c) baryon is reconstructed via both the Xi(0)(c) -> Xi(-) pi(+) and Xi(0)(c) -> Xi(-) e(+) nu(e) decay channels in the range 2 < p(T) < 12 GeV/c. The baryon-to-meson ( Xi(0,+)(c) /D-0) and the baryon-to-baryon (Xi(0,+)(c) /Lambda(+)(c)) production yield ratios show no significant dependence on multiplicity. In addition, the observed yield ratios are not described by theoretical predictions that model charm-quark fragmentation based on measurements at e(+)e(-) and e(-)p colliders, indicating differences in the charm-baryon production mechanism in pp collisions. A comparison with different event generators and tunings, including different modelling of the hadronisation process, is also discussed. Moreover, the branching-fraction ratio of BR( Xi(0)(c) -> Xi(-) e(+) nu(e))/BR( Xi(0)(c) -> Xi(-) pi(+)) is measured as 0.825 +/- 0.094 (stat.) +/- 0.081 (syst.). This value supersedes the previous ALICE measurement, improving the statistical precision by a factor of 1.6.