Measurements of long-range correlations and $v_{2}(eta)$ in small system with ALICE

Measurements of long-range angular correlations are one of the important tools to evaluate the interplay between the initial- and final-state effects in small collision systems in view of understanding the evidence of collectivity. The charged-particle multiplicity distribution as a function of pseudorapidity ($eta$) is asymmetric in p--Pb collisions. Since the mean free path depends on multiplicity, the $v_{n}(eta)$ reflects the dynamics of collectivity in p--Pb collisions. The measurement of $v_{n}(eta)$ in p--Pb collisions is an important study of how charged-particle multiplicity and anisotropic flow relate to the longitudinal evolution of the system. In this talk, we present results of super long-range two-particle azimuthal correlations and $v_{2}(eta)$ in p--Pb collisions at $sqrt{s_{NN}}$ = 5.02 TeV and also pp collisions at $sqrt{s}$ = 13 TeV measured with ALICE. These measurements utilize the Forward Multiplicity Detector, which allows for unprecedented pseudorapidity ranges to be explored (up to $Deltaeta~$ 8) and allow to measure the $eta$ dependence of $v_{2}$ over a wide pseudorapidity range (−3.1 $< eta<$ 4.8). Results are compared with the AMPT and hydrodynamical calculations.