Associated production of V+quarkonia at ATLAS and CMS

The associated production of quarkonium with a vector boson or an additional quarkonium state are rare processes that provide new insight into QCD models of quarkonium production, but also provide new opportunities to study double parton scattering. We present new measurements of associated quarkonium production with cross-section measurements in single and double parton scattering dominated regimes and a precise assessment of the sigma_eff parameter governing the effective spatial area of parton-parton interactions at a variety of energy scales.