13-19 May 2018
Venice, Italy
Europe/Zurich timezone
The organisers warmly thank all participants for such a lively QM2018! See you in China in 2019!

Scalar product and event plane methods for measurements of azimuthal anisotropy in Pb+Pb and Xe+Xe collisions with the ATLAS detector at the LHC

15 May 2018, 17:00
2h 40m
First floor and third floor (Palazzo del Casinò)

First floor and third floor

Palazzo del Casinò

Poster Correlations and fluctuations Poster Session


Klaudia Burka (Polish Academy of Sciences (PL))


Measurements of the azimuthal anisotropy of charged particles in heavy-ion collisions are sensitive to the detailed properties of the quark-gluon plasma, in particular its dependence on initial conditions, transport coefficients and time evolution. The presented measurements are based on 0.49 n$\mathrm{b}^{-1}$ of Pb+Pb data collected by the ATLAS detector in 2015 with center-of-mass energy $\sqrt{s_{NN}}=5.02$ TeV. The elliptic flow and higher-order Fourier coefficients ($v_{2}$ - $v_{7}$) are presented in a wide range of transverse momenta ($p_\mathrm{T}<60$ GeV), pseudorapidity ($|\eta|<2.5$) and 0-80% collision centrality. The collected minimum-bias sample is enhanced by triggers for "ultra-central" collisions, providing an opportunity to perform precise measurements of flow harmonics in the fluctuation-dominated regime. The magnitude of azimuthal anisotropy is estimated by measuring the angular correlations of produced particles using both the scalar product and event plane methods. To suppress non-flow, $v_{n}$ harmonics are calculated by correlating two flow vectors estimated in two different detectors separated in pseudorapidity (the forward calorimeter $3.2<|\eta|<4.8$, or the inner detector $|\eta|<2.5$), and in the opposite hemispheres. The obtained results are compared to the $v_{n}(p_\mathrm{T})$ values at measured in $\sqrt{s_{NN}}=2.76$ TeV Pb+Pb collisions and recent $\sqrt{s_{NN}}=5.44$ TeV Xe+Xe collisions as well as to predictions of hydrodynamical models.

Content type Experiment
Collaboration ATLAS
Centralised submission by Collaboration Presenter name already specified

Primary authors

Barbara Krystyna Wosiek (Institute of Nuclear Physics Polish Academy of Sciences (PL)) Klaudia Burka (Polish Academy of Sciences (PL))

Presentation materials