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The second-order azimuthal anisotropy Fourier harmonics, v2, are obtained in p-Pb and PbPb collisions over a wide pseudorapidity ([eta]) range based on correlations among six or more charged particles. The p-Pb data, corresponding to an integrated luminosity of 35 nb-1, were collected during the 2013 LHC p-Pb run at a nucleon-nucleon center-of-mass energy of 5.02 TeV by the CMS experiment. A sample of semiperipheral PbPb collision data at √sNN=2.76 TeV, corresponding to an integrated luminosity of 2.5 [mu]b-1 and covering a similar range of particle multiplicities as the p-Pb data, is also analyzed for comparison. The six- and eight-particle cumulant and the Lee-Yang zeros methods are used to extract the v2 coefficients, extending previous studies of two- and four-particle correlations. For both the p-Pb and PbPb systems, the v2 values obtained with correlations among more than four particles are consistent with previously published four-particle results. These data support the interpretation of a collective origin for the previously observed long-range (large [Delta][eta]) correlations in both systems. The ratios of v2 values corresponding to correlations including different numbers of particles are compared to theoretical predictions that assume a hydrodynamic behavior of a p-Pb system dominated by fluctuations in the positions of participant nucleons. These results provide new insights into the multiparticle dynamics of collision systems with a very small overlapping region.
Quantum Chromodynamics, which describe the interactions of quarks and gluons, have been found not to violate global parity symmetry. However, the possibility of local parity violations due to transitions in the vacuum state of QCD is not excluded. The effects of these parity violations could be measured in the hot and dense medium created in the ultrarelativistic heavy ion collisions experiment conducted at the Large Hadron Collider, called a Quark-Gluon Plasma, in which the quarks that compose most of ordinary matter are deconfined. In the strong magnetic fields which permeate the QGP in non-central collisions, parity violation would express itself as a charge asymetry with respect to the reaction plane, a phenomenon called the Chiral Magnetic Effect. The measurements of the charge-dependent correlations in a heavy-ion collisions allows to experimentally probe effects of the CME. These measurements are conducted via the use of the second harmonic two-particle correlator with respect to the reaction plane, $\langle\cos(\phi_{a}+\phi_{b}-2\psi)\rangle$ The background affecting these measurements is the consequence of an interplay of strong anisotropic flow and correlations unrelated to the CME. Correlations with respect to the fourth harmonic, $\langle\cos(2\phi_{a}+2\phi_{b}-4\psi)\rangle$, are insensitive to the CME and can be used to estimate the magnitude of these background effects. In this thesis, we present results from charge-dependent correlations with respect to both the second and fourth harmonic event planes measured in Pb+Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV at the LHC using data from the ALICE detector. We also present calculations of the ratio of the fourth to second harmonics based on the blast-wave model, which serve as a baseline to understand how these background effects scale between one harmonic and another.