Left: Self-normalised yields of e$^{\pm}$ $\leftarrow$ W$^{\pm}$ and associated hadrons as a function of the normalised charged-particle pseudorapidity density at midrapidity in pp collisions at $\sqrt{s}=$ 13 TeV, compared with the expectations from PYTHIA 8  simulations including MPI and with/without CR effects. Right: self-normalised yields of e$^{\pm}$ $\leftarrow$ W$^{\pm}$ and associated hadrons compared with J/$\psi \rightarrow \textrm{e}^{+}\textrm{e}^{-}$ at midrapidity ($|y_{ee}|$ 0.9)  and J/$\psi \rightarrow {\rm \mu^{+}\mu^{-}}$ at forward rapidity (2.5 $< y_ all yields being measured as a function of the self-normalised charged-particle pseudorapidity density at midrapidity. statistical and systematic uncertainties measurements are shown vertical lines open respectively.>< /y_>