Dihadron correlations in PbPb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV with CMS

Measurements of charged dihadron $\Delta\eta$$-$$\Delta\phi$ correlations from the CMS collaboration are presented for PbPb collisions at a center-of-mass energy of 2.76 TeV per nucleon pair over a broad range of pseudorapidity and the full range of azimuthal angle. A significant correlated yield is observed for pairs of particles with small $\Delta\phi$ but large longitudinal separation $\Delta\eta$, commonly known as the ``ridge''. The ridge persists up to at least $\mid$$\Delta\eta$$\mid$ = 4 and the dependence of the ridge region shape and yield on collision centrality and transverse momentum has been measured. A Fourier analysis of the long-range two-particle correlation is presented and discussed in the context of higher order flow coefficients.