An excess of J/ψ yield at very low transverse momentum (pT < 0.3 GeV/c), originating from coherent photoproduction, is observed in peripheral and semicentral hadronic Pb–Pb collisions at a center-ofmass energy per nucleon pair of √ sNN = 5.02 TeV. The measurement is performed with the ALICE detector via the dimuon decay channel at forward rapidity (2.5 < y <4). The nuclear modification factor at very low pT and the coherent photoproduction cross section are measured as a function of centrality down to the 10% most central collisions. These results extend the previous study at √ sNN = 2.76 TeV, confirming the clear excess over hadronic production in the pT range 0 − 0.3 GeV/c and the centrality range 70–90%, and establishing an excess with a significance greater than 5σ also in the 50–70% and 30–50% centrality ranges. The results are compared with earlier measurements at √ sNN = 2.76 TeV and with different theoretical predictions aiming at describing how coherent photoproduction occurs in hadronic interactions with nuclear overlap.

Acharya, S., Adamová, D., Adler, A., Aglieri Rinella, G., Agnello, M., Agrawal, N., et al. (2023). Photoproduction of low-pT J/ψ from peripheral to central Pb–Pb collisions at 5.02 TeV. PHYSICS LETTERS. SECTION B, 846, 1-14 [10.1016/j.physletb.2022.137467].

Photoproduction of low-pT J/ψ from peripheral to central Pb–Pb collisions at 5.02 TeV

Agrawal, N.;Alici, A.;Arcelli, S.;Bellini, F.;Carnesecchi, F.;Cifarelli, L.;Colocci, M.;Ercolessi, F.;Giacalone, M.;Jacazio, N.;Rubini, N.;Scioli, G.;Strazzi, S.;
2023

Abstract

An excess of J/ψ yield at very low transverse momentum (pT < 0.3 GeV/c), originating from coherent photoproduction, is observed in peripheral and semicentral hadronic Pb–Pb collisions at a center-ofmass energy per nucleon pair of √ sNN = 5.02 TeV. The measurement is performed with the ALICE detector via the dimuon decay channel at forward rapidity (2.5 < y <4). The nuclear modification factor at very low pT and the coherent photoproduction cross section are measured as a function of centrality down to the 10% most central collisions. These results extend the previous study at √ sNN = 2.76 TeV, confirming the clear excess over hadronic production in the pT range 0 − 0.3 GeV/c and the centrality range 70–90%, and establishing an excess with a significance greater than 5σ also in the 50–70% and 30–50% centrality ranges. The results are compared with earlier measurements at √ sNN = 2.76 TeV and with different theoretical predictions aiming at describing how coherent photoproduction occurs in hadronic interactions with nuclear overlap.
2023
Acharya, S., Adamová, D., Adler, A., Aglieri Rinella, G., Agnello, M., Agrawal, N., et al. (2023). Photoproduction of low-pT J/ψ from peripheral to central Pb–Pb collisions at 5.02 TeV. PHYSICS LETTERS. SECTION B, 846, 1-14 [10.1016/j.physletb.2022.137467].
Acharya, S.; Adamová, D.; Adler, A.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S.U.; Ahuja, I.; Akindinov, A.; Al-Tu...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/954527
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