Measurement of the underlying event using track-jets with the CMS experiment

A measurement of the underlying event activity in pp collisions is performed using events with a leading charged particle jet produced at central pseudorapidities and of transverse momentum in the range of 1 to 100 GeV. The underlying event activity is measured independently in the two halves of the transverse region with the maximum as well as minimum activities. The results obtained from pp collisons at center-of-mass energies of 0.9, 2.76 and 7 TeV are presented and compared to model predictions.