Multiplicity-dependent inclusive J$\textit{/ψ}$ production at forward rapidity in pp collisions at = 13 TeV

This paper presents a study of the inclusive forward J$\textit{/ψ}$ yield as a function of forward charged-particle multiplicity in pp collisions at = 13 TeV using data collected by the ALICE experiment at the CERN LHC. The results are presented in terms of relative $\textit{J/ψ}$ yields and relative charged-particle multiplicities with respect to these quantities obtained in inelastic collisions having at least one charged particle in the pseudorapidity range |$\textit{η}$| $\textit{<}$ 1. The J$\textit{/ψ}$ mesons are reconstructed via their decay into $\textit{μ}$ $\textit{μ}$ pairs in the forward rapidity region (2$\textit{.}$5 $\textit{< y <}$ 4). The relative multiplicity is estimated in the forward pseudorapidity range which overlaps with the J$\textit{/ψ}$ rapidity region. The results show a steeper-than-linear increase of the J$\textit{/ψ}$ yields versus the multiplicity. They are compared with previous measurements and theoretical model calculations.