Gluonic hot spots and spatial correlations inside the proton

In this talk, based on arXiv:1605.09176, we present a microscopic realization of the hollowness effect observed in proton-proton scattering at √s=7 TeV. Additionally, we show how the initial collision geometry proposed in our model influences significantly the eccentricities of p+p collisions. This is a highly debated topic as the analysis of the LHC experimental data have indicated suggestive signals of collective phenomena in high multiplicity p+p collisions. The hollowness effect, not observed at lower energies, consists in a depletion of the inelasticity density at zero impact parameter of the collision. Our analysis is based on three main ingredients: we rely on gluonic hot spots inside the proton as effective d.o.f for the description of the scattering process. Next we assume that non-trivial correlations between the transverse positions of the hot spots inside the proton exist. Finally we build the scattering amplitude from a multiple scattering, Glauber-like series of collisions between hot spots. In our approach, the onset of the hollowness effect is naturally explained due to the diffusion of the hot spots in the transverse plane with increasing collision energy.