부산대학교 도서관

The measurement of charmonium states produced in proton-neon ( p Ne ) collisions by the LHCb experiment in its fixed-target configuration is presented. The production of J / ψ and ψ (2 S) mesons is studied with a beam of 2.5 Te V protons colliding on gaseous neon targets at rest, corresponding to a nucleon-nucleon centre-of-mass energy s NN = 68.5 Ge V . The data sample corresponds to an integrated luminosity of 21.7 ± 1.4 nb - 1 . The J / ψ and ψ (2 S) hadrons are reconstructed in μ + μ - final states. The J / ψ production cross-section per target nucleon in the centre-of-mass rapidity range y ⋆ ∈ [ - 2.29 , 0 ] is found to be 506 ± 8 ± 46 nb/nucleon . The ratio of J / ψ and D 0 cross-sections is evaluated to (1.06 ± 0.02 ± 0.09) % . The ψ (2 S) to J / ψ relative production rate is found to be (1.67 ± 0.27 ± 0.10) % in good agreement with other measurements involving beam and target nuclei of similar sizes. [ABSTRACT FROM AUTHOR]