Measurement of the production cross-section of J/ψ and ψ(2S) mesons at high transverse momentum in pp collisions at √s = 13 TeV with the ATLAS detector Zakareishvili Tamar High Energy Physics Institute of Tbilisi State University 2020 The measurements of the prompt and non-prompt differential cross-sections of J/ψ and ψ(2S) mesons in high transverse momentum range are reported. The measurements of the non-prompt fractions of ψ(2S) and J/ψ, and prompt and non-prompt production ratios of ψ(2S) to J/ψ are also presented. The analysis is performed using pp collision data recorded by the ATLAS detector at √s = 13 TeV during Run 2 of the LHC, corresponding to 139/fb of integrated luminosity. PUBLATLASSLIDE