Speaker
Description
The second- and third-order azimuthal anisotropy Fourier harmonics are studied in pPb collisions at $\sqrt{s_{_\text{NN}}}=8.16~\mathrm{TeV}$ over a wide range of event multiplicities. Multiparticle correlations are used to isolate global properties stemming from the collision overlap geometry. The second-order, elliptic'' harmonic moment is obtained with high precision through four-, six-, and eight-particle correlations and, for the first time, the third-order,triangular'' harmonic moment is studied using four-particle correlations. A sample of peripheral PbPb collisions at $\sqrt{s_{_{\text{NN}}}}=5.02~\mathrm{TeV}$ that covers a similar range of event multiplicities to the pPb results is also analyzed. Model calculations of initial-state fluctuations in pPb and PbPb collisions can be directly compared to the high precision experimental results. This work provides new insight on the fluctuation-driven geometry at the earliest stages of heavy ion collisions.
