The factorisation ratio $r_{2}$, as a function of $p_{\rm T}^{\, a}$ in bins of $p_{\rm T}^{t}$ for multiplicity classes 0--20$\%$, 20--40$\%$ and 40--60$\%$ in p--Pb collisions at $\sqrt{s_{_{\rm NN}}} = 5.02$ TeV, are presented by solid magenta circles DPMJET calculations are presented by pink shaded areas Hydrodynamic calculations (MUSIC) with modified MC-Glauber initial conditions and $\eta/s =$ 0.08 are shown as magenta lines .