Measurement of the J/ ψ production cross section in 920 GeV/c fixed-target proton-nucleus interactions

Abstract The mid-rapidity ( d σ p N / d y at y = 0 ) and total ( σ p N ) production cross sections of Jψ mesons are measured in proton–nucleus interactions. Data collected by the HERA-B experiment in interactions of 920  GeV / c protons with carbon, titanium and tungsten targets are used for this analysis. The Jψ mesons are reconstructed by their decay into lepton pairs. The total production cross section obtained is σ p N J / ψ = 663 ± 74 ± 46  nb / nucleon . In addition, our result is compared with previous measurements.