Hadron multiplicities in p+p and p+Pb collisions at the LHC

Experiments at the Large Hadron Collider（LHC）have measured multiplicity distributions in p+p and p+Pb collisions at a new domain of collision energy.Based on considering an energy-dependent broadening of the nucleon’s density distribution,charged hadron multiplicities are studied with the phenomenological saturation model and the evolution equation dependent saturation model.By assuming the saturation scale has a small dependence on the 3-dimensional root mean square（rms）radius at different energy,the theoretical results are in good agreement with the experimental data from CMS and ALICE collaboration.The predictive results in p+p collisions at s;=14 TeV of the LHC are also given.