Distribution of multiple scatterings in proton-nucleus collisions at high energy

We consider proton-nucleus collisions at high energy in the Color Glass Condensate framework, and extract from the gluon production cross-section the probabilities of having a definite number of multiple scatterings in the nucleus. Various properties of the distribution of the number of multiple scatterings are studied, and we conclude that events in which the momentum of a hard jet is compensated by many much softer particles on the opposite side are very unlikely except for extreme values of the saturation momentum. In the same framework, we also investigate the possibility to estimate the impact parameter of a proton-nucleus collision, from the measure of the multiplicity of its final state.