engleski

Energy dependence of exclusive J/ψ photoproduction off protons in ultra-peripheral p–Pb collisions at √sNN=5.02 TeV

The ALICE Collaboration has measured the energy dependence of exclusive photoproduction of J/ψ vector mesons off proton targets in ultra– peripheral p–Pb collisions at a centre-of-mass energy per nucleon pair √sNN=5.02 TeV. The e+ e− and μ+μ− decay channels are used to measure the cross section as a function of the rapidity of the J/ψ in the range y<-2.5, 2.7> , corresponding to an energy in the γ p centre- of- mass in the interval Wγp<40, 550> GeV. The measurements, which are consistent with a power law dependence of the exclusive J/ψ photoproduction cross section, are compared to previous results from HERA and the LHC and to several theoretical models. They are found to be compatible with previous measurements.

J/psi(3100) photoproduction ; p target ; nucleon pair ; muon: spectrometer ; p nucleus: scattering ; time projection chamber ; energy dependence ; DESY HERA Stor ; CERN LHC Coll ; vector meson ; rapidity ; ALICE ; experimental results ; 5020 GeV-cms/nucleon

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