First measurement of Λc+ production down to pT=0 in pp and p-Pb collisions at √sNN=5.02 TeV

作者：Acharya, S.; Adamova, D.; Adler, A.; Adolfsson, J.; Aggarwal, M. M.; Rinella, G. Aglieri; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Akindinov, A.; Al-Turany, M.; Alam, S. N.; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; Alfanda, H. M.; Alfaro Molina, R.; Ali, B.; Ali, Y.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altenkamper, L.; Altsybeev, I.; Anaam, M. N.; Andrei, C.; Andreou, D.; Andrews, H. A.; Andronic, A.; Angeletti, M.; Anguelov, V.; Anson, C.; Anticic, T.

来源：Physical Review C - Nuclear Physics, 2023, 107(6): 064901.

DOI：10.1103/PhysRevC.107.064901

• PROTON-PROTON
• CHARGED-PARTICLES
• MESON PRODUCTION
• RAPIDITY
• HADRONS
• PION

The production of prompt Lambda(+)(c) baryons has been measured at midrapidity in the transverse momentum interval 0 < pT < 1 GeV/c for the first time, in pp and p-Pb collisions at a center-of-mass energy per nucleon-nucleon collision root s(NN) = 5.02 TeV. The measurement was performed in the decay channel Lambda(+)(c) . pK0 S by applying new decay reconstruction techniques using a Kalman-Filter vertexing algorithm and adopting a machine-learning approach for the candidate selection. The pT -integrated Lambda(+)(c) production cross sections in both collision systems were determined and used along with the measured yields in Pb-Pb collisions to compute the pT -integrated nuclear modification factors RpPb and RAA of Lambda(+)(c) baryons, which are compared to model calculations that consider nuclear modification of the parton distribution functions. The Lambda(+)(c) /D0 baryon-to-meson yield ratio is reported for pp and p-Pb collisions. Comparisons with models that include modified hadronization processes are presented, and the implications of the results on the understanding of charm hadronization in hadronic collisions are discussed. A significant (3.7s) modification of the mean transverse momentum of Lambda(+)(c) baryon