Scaling properties of the underlying event in high energy pp collisions

ATLAS results on underlying event in pp collisions at √s = 0.9, 7 and 13 TeV have been studied. It is shown that the center-of-mass energy dependences of the charged-particle production sensitive to the underlying event (transverse region) and to the hardest partonic interaction (towards and away regions) in pp collisions can be both understood in terms of the change of the inclusive average multiplicity. Within uncertainties, the corresponding particle production as a function of the leading charged particle shows no significant √s-dependence for the three regions once they are scaled according to the relative change in multiplicity (∣η∣ < 2:5, p_T > 0:5 GeV/c)