$\psi(2S)$ production as a function of charged-particle multiplicity in pp collisions at $\sqrt{s}$= 13 TeV and p--Pb collisions at $\sqrt{s_{\mathrm{NN}}}$= 8.16 TeV with ALICE at the LHC

The self-normalised 𝜓(2S) yields as a function of charged-particle multiplicity in pp collisions at√𝑠 = 13 TeV and p–Pb collisions at √𝑠NN = 8.16 TeV, using the ALICE detector at the CERN LHC,are reported in these proceedings. This measurement represents one of the main tools to understand therole of multiparton interactions and their influence on charmonium production in small systems,i.e pp and pA collisions. The ratio of 𝜓(2S)-over-J/𝜓 as a function of charged-particle multiplicityis also presented for both pp and p–Pb collisions. The comparison to theoretical calculations isreported