  The aim of this paper is to understand resonance production (and more
generally particle production) for different collision systems, namely
proton-proton (pp), proton-nucleus (pA), and nucleus-nucleus (AA) scattering at
the LHC. We will investigate in particular particle yields and ratios versus
multiplicity, using the same multiplicity definition for the three different
systems, in order to analyse in a compact way the evolution of particle
production with the system size and the origin of a very different system size
dependence of the different particles.
