Cluster properties from two-particle angular correlations in pp collisions at sqrts = 0.9, 2.36 and 7\TeV

We present results on two-particle angular correlations in proton-proton collisions at center of mass energies of 0.9, 2.36 and 7\TeV over a broad range of pseudorapidity ($\eta$) and azimuthal angle ($\phi$). The data were collected with the CMS detector during LHC run in December 2009 and March 2010. At all three energies, a complex two-dimensional correlation structure in $\Delta \eta$ and $\Delta \phi$ is observed. In the context of an independent cluster parameterization of short-range correlations, the cluster size and its decay width are extracted from the two-particle pseudorapidity correlation function and compared with previous measurements in proton-proton and proton-antiproton collisions, as well as PYTHIA predictions. The results at 0.9\TeV are in agreement with previous measurements. The new results at 2.36 and 7\TeV represent the highest-energy measurements at a particle collider to date.