Measurements of the inclusive J/$\psi$ yield as a function of charged-particle pseudorapidity density ${ \rm d}N_{ \rm ch}/\rm{ d}\eta$ in pp collisions at $\sqrt{ s}$ = 13 TeV with ALICE at the LHC are reported. The J/$\psi$ meson yield is measured at midrapidity ($|y|<0.9$) in the dielectron channel, for events selected based on the charged-particle multiplicity at midrapidity ($|\eta|<1$) and at forward rapidity ($-3.7<\eta<-1.7$ and $2.8<\eta<5.1$); both observables are normalized to their corresponding averages in minimum bias events. The increase of the normalized J/$\psi$ yield with normalized ${ \rm d}N_{ \rm ch}/\rm{ d}\eta$ is significantly stronger than linear and dependent on the transverse momentum. The data are compared to theoretical predictions, which describe the observed trends well, albeit not always quantitatively.
Categories: nucl-ex hep-ex