Quark Matter 2019 - the XXVIIIth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions

Using Event Shape Engineering to study anisotropic flow of inclusive and identified particles in Pb-Pb collisions with ALICE

4 Nov 2019, 17:40

20m

Wanda Han Show Theatre & Wanda Reign Wuhan Hotel

Poster Presentation Initial state and approach to equilibrium Poster Session

Speaker

Catalin Ristea (Institute of Space Science (RO))

Description

Heavy-ion collisions produce asymmetric pressure gradients which convert via interactions the initial spatial asymmetry into an anisotropy in final state momentum space, a phenomenon referred to as anisotropic flow. Anisotropic flow is characterized using the harmonic coefficients $v_{\mathrm{n}}$ in a Fourier decomposition of the azimuthal distribution of produced particles relative to the symmetry plane in a collision. It is found that flow fluctuates event-by-event due to fluctuations in the initial geometry, which allows for an efficient selection of events that correspond to a specific initial geometry. This technique, called Event Shape Engineering, was applied to select events within the same centrality but having very different values of the elliptic ($v_2$) and triangular ($v_3$) flow coefficients. For those events, we present results on centrality, transverse momentum ($p_{\mathrm{T}}$) and event-shape dependence of anisotropic flow for inclusive and identified (${\pi }^{\pm }$, $K^{\pm }$, $\mathrm{p}+\bar{\mathrm{p}}$, $\mathrm{\Lambda }+\bar{\mathrm{\Lambda }}$, ${\mathrm{K}}_{\mathrm{S}}^0$, ${\mathrm{\Xi }}^{-}+{\bar{\mathrm{\Xi }}}^{+}$, and ${\mathrm{\Omega }}^{-}+{\bar{\mathrm{\Omega }}}^{+}$) particles in Pb--Pb collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}=5.02$ TeV recorded by the ALICE detector in 2015 and 2018. We also investigate the correlation between $v_2$ of inclusive and identified particles averaged over low and high $p_{\mathrm{T}}$ ranges.

Presentation materials

QM2019-Wuhan-posterCatalinv_final.pdf