Cross sections for the coherent photoproduction of 0 vector mesons in ultraperipheral Pb-Pb collisions at p sNN = 5:02TeV are reported. The measurements, which rely on the pi+pi- decay channel, are presented in three regions of rapidity covering the range jyj < 0:8. For each rapidity interval, cross sections are shown for dierent nuclear breakup classes dened according to the presence of neutrons measured in the zero-degree calorimeters. The results are compared with predictions based on dierent models of nuclear shadowing. Finally, the observation of a coherently produced resonance-like structure with a mass around 1.7 GeV/c2 and a width of about 140 MeV/c2 is reported and compared with similar observations from other experiments.
Coherent photoproduction of ρ0 vector mesons in ultra-peripheral Pb-Pb collisions at $$ sqrt{{mathrm{s}}_{mathrm{NN}}} $$ = 5.02 TeV
Colella, D.;Di Bari, D.Membro del Collaboration Group
;Mazzilli, M.;Volpe, G.Membro del Collaboration Group
;
2020-01-01
Abstract
Cross sections for the coherent photoproduction of 0 vector mesons in ultraperipheral Pb-Pb collisions at p sNN = 5:02TeV are reported. The measurements, which rely on the pi+pi- decay channel, are presented in three regions of rapidity covering the range jyj < 0:8. For each rapidity interval, cross sections are shown for dierent nuclear breakup classes dened according to the presence of neutrons measured in the zero-degree calorimeters. The results are compared with predictions based on dierent models of nuclear shadowing. Finally, the observation of a coherently produced resonance-like structure with a mass around 1.7 GeV/c2 and a width of about 140 MeV/c2 is reported and compared with similar observations from other experiments.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.