Measurement of (2S) production as a function of charged-particle pseudorapidity density in pp collisions at √s=13 TeV and p-Pb collisions at √sNN=8.16 TeV with ALICE at the LHC

作者：Acharya, S.; Adamova, D.; Adler, A.; Rinella, G. Aglieri; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Ahuja, I.; Akindinov, A.; Al-Turany, M.; Aleksandrov, D.; Alessandro, B.; Alfanda, H. M.; Alfaro Molina, R.; Ali, B.; Ali, Y.; Alici, A.; Alizadehvandchali, N.; Alkin, A.; Alme, J.; Alocco, G.; Alt, T.; Altsybeev, I.; Anaam, M. N.; Andrei, C.; Andronic, A.; Anguelov, V.; Antinori, F.; Antonioli, P.; Anuj, C.; Apadula, N.; Aphecetche, L.; Appelshaeuser, H.; Arcelli, S.

来源：JOURNAL OF HIGH ENERGY PHYSICS, 2023, (6): 147.

DOI：10.1007/JHEP06(2023)147

• Jets and Jet Substructure
• Properties of Hadrons

Production of inclusive charmonia in pp collisions at center-of-mass energy of root s = 13TeV and p-Pb collisions at center-of-mass energy per nucleon pair of root sNN = 8.16TeV is studied as a function of charged-particle pseudorapidity density with ALICE. Ground and excited charmonium states ( J/psi, psi(2S)) are measured from their dimuon decays in the interval of rapidity in the center-of-mass frame 2.5 < y(cms) < 4.0 for pp collisions, and 2.03 < y(cms) < 3.53 and -4.46 < y(cms) < -2.96 for p-Pb collisions. The charged-particle pseudorapidity density is measured around midrapidity (| eta | < 1.0). In pp collisions, the measured charged-particle multiplicity extends to about six times the average value, while in p-Pb collisions at forward (backward) rapidity a multiplicity corresponding to about three (four) times the average is reached. The psi(2S) yield increases with the charged-particle pseudorapidity density. The ratio of psi(2S) over J/ yield does not show a significant multiplicity dependence in either colliding system, suggesting a similar behavior of J/ and psi(2S) yields with respect to charged-particle pseudorapidity density. Results for the psi(2S) yield and its ratio with respect to J/psi agree with available model calculations.