Non-linear flow modes of identified particles in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV

Abstract

The $p_{\mathrm{T}}$-differential non-linear flow modes, $v_{4,22}$, $v_{5,32}$, $v_{6,33}$ and $v_{6,222}$ for ${\pi }^{\pm }$, ${\mathrm{K}}^{\pm }$ , ${\mathrm{K}}_{\mathrm{S}}^0$ , p + $\overline{\mathrm{p}}$, $\Lambda$ + $\overline{\Lambda }$ and $\varphi$-meson have been measured for the first time at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV in Pb-Pb collisions with the ALICE detector at the Large Hadron Collider. The results were obtained with a multi-particle technique, correlating the identified hadrons with reference charged particles from a different pseudorapidity region. These non-linear observables probe the contribution from the second and third order initial spatial anisotropy coefficients to higher flow harmonics. All the characteristic features observed in previous $p_{\mathrm{T}}$-differential anisotropic flow measurements for various particle species are also present in the non-linear flow modes, i.e. increase of magnitude with increasing centrality percentile, mass ordering at low $p_{\mathrm{T}}$ and particle type grouping in the intermediate $p_{\mathrm{T}}$ range. Hydrodynamical calculations (iEBE-VISHNU) that use different initial conditions and values of shear and bulk viscosity to entropy density ratios are confronted with the data at low transverse momenta. These calculations exhibit a better agreement with the anisotropic flow coefficients than the non-linear flow modes. These observations indicate that non-linear flow modes can provide additional discriminatory power in the study of initial conditions as well as new stringent constraints to hydrodynamical calculations.

45 pages, 25 captioned figures, 4 tables, authors from page 37, published version, figures at http://alice-publications.web.cern.ch/node/6001

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Cited by in corpus (7)

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• $\Sigma (1385{)}^{\pm }$ resonance production in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Elliptic flow of charged particles at midrapidity relative to the spectator plane in Pb-Pb and Xe-Xe collisions
• Bayesian reconstruction of anisotropic flow fluctuations at fixed impact parameter
• Investigations of the linear and non-linear flow harmonics using the A Multi-Phase Transport model
• Linear and non-linear flow modes of charged and identified particles in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}$=5.02 TeV with ALICE