J/$\psi$ production as a function of charged-particle multiplicity in p-Pb collisions at $\sqrt{\textit{s}_{\rm NN}}~=~8.16$ TeV

Inclusive J\ $\psi$ yields and average transverse momenta in p-Pb collisions at a center-of-mass energy per nucleon pair $\sqrt{s_{\rm NN}}$ = 8.16 TeV are measured as a function of the charged-particle pseudorapidity density with ALICE. The J\ $\psi$ mesons are reconstructed at forward ($2.03 < y_{cms} < 3.53$) and backward ($-4.46 < y_{cms} < -2.96$) center-of-mass rapidity in their dimuon decay channel while the charged-particle pseudorapidity density is measured around midrapidity. The J\ $\psi$ yields at forward and backward rapidity normalized to their respective average values increase with the normalized charged-particle pseudorapidity density, the former showing a weaker increase than the latter. The normalized average transverse momenta at forward and backward rapidity manifest a steady increase from low to high charged-particle pseudorapidity density with a saturation beyond the average value.