  Measurements of two- and four-particle angular correlations for charged
particles emitted in pPb collisions are presented over a wide range in
pseudorapidity and full azimuth. The data, corresponding to an integrated
luminosity of approximately 31 inverse nanobarns, were collected during the
2013 LHC pPb run at a nucleon-nucleon center-of-mass energy of 5.02 TeV by the
CMS experiment. The results are compared to 2.76 TeV semi-peripheral PbPb
collision data, collected during the 2011 PbPb run, covering a similar range of
particle multiplicities. The observed correlations are characterized by the
near-side (abs(Delta(phi)~0) associated pair yields and the azimuthal
anisotropy Fourier harmonics (v[n]). The second-order (v[2]) and third-order
(v[3]) anisotropy harmonics are extracted using the two-particle azimuthal
correlation technique. A four-particle correlation method is also applied to
obtain the value of v[2] and further explore the multi-particle nature of the
correlations. Both associated pair yields and anisotropy harmonics are studied
as a function of particle multiplicity and transverse momentum. The associated
pair yields, the four-particle v[2], and the v[3] become apparent at about the
same multiplicity. A remarkable similarity in the v[3] signal as a function of
multiplicity is observed between the pPb and PbPb systems. Predictions based on
the color glass condensate and hydrodynamic models are compared to the
experimental results.
