Charged particle production in p+Pb collisions with the ATLAS detector

We report on the measurements of centrality dependence of the charged particle pseudorapidity distribution and transverse momentum distributions in proton-lead collisions with the ATLAS detector at LHC. The data were collected in 2012 run providing proton-nucleus collisions at $\sqrt{s_{NN}} = 5.02$ TeV. These measurements are expected to contribute to understanding the initial state of the nuclear wave function. The presented results also points to the importance of understanding the fluctuating nature of the nucleon-nucleon collisions.