Long range forward-backward rapiditiy correlations in proton-proton collisions at LHC

We argue that string percolation is in the origin of i) an approximately flat rapidity distribution and of ii) an approximately constant forward-backward correlation parameter $b$ over a substantial fraction of the available rapidity. Predictions are given for $pp$ collisions at LHC, $\sqrt{s}=14$TeV and $\sqrt{s}=5.5$TeV.