Observation and measurements of the production of prompt and non-prompt ${J/\psi}$ mesons in association with a ${Z}$ boson in ${pp}$ collisions at ${\sqrt{s} = 8\,\mathrm{TeV}}$ with the ATLAS detector

The associated production of vector boson with heavy quarkonia is a key observable for understanding the quarkonium production mechanisms. In this poster we present the first evidence of the production of the Z boson in asso- ciation with a prompt and non-prompt J/ψ meson and measure its production rate in comparison of the inclusive Z production. Relative contributions to the signal from single and double parton scattering are estimated. We compare sin- gle parton scattering cross-sections to cutting-edge theoretical calculations in the colour singlet and colour octet formalisms. Finally, we extract a lower limit in the double parton scattering effective cross section.