Kurtosis of elliptic flow fluctuations

Abstract

Elliptic flow ($v_2$) in ultrarelativistic nucleus-nucleus collisions fluctuates event to event, both in magnitude and in orientation with respect to the reaction plane. Even though the reaction plane is not known event to event in experiment, we show that the statistical properties of $v_2$ fluctuations in the reaction plane can be precisely extracted from experimental data. Previous studies have shown how to measure the mean, variance and skewness using the first three cumulants $v_2\{2\}$, $v_2\{4\}$ and $v_2\{6\}$. We complement these studies by providing a formula for the kurtosis, which requires an accurate determination of the next cumulant $v_2\{8\}$. Using existing data, we show that the kurtosis is positive for most centralities, in contrast with the kurtosis of triangular flow fluctuations, which is negative. We argue that these features are robust predictions of fluid-dynamical models.

8 pages; 4 figures; v2: published version, figure 3 uses actual CMS data

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Cited by in corpus (14)

• Separating the impact of nuclear skin and nuclear deformation in high-energy isobar collisions
• Elliptic flow fluctuations in central collisions of spherical and deformed nuclei
• New paradigm for fluctuations in heavy-ion collisions
• Anisotropy fluctuation and correlation in central $\alpha$-clustered ${}^{12}$C+${}^{197}$Au collisions
• Predictions for the sPHENIX physics program
• Measures of azimuthal anisotropy in high-energy collisions
• Fluctuations of anisotropic flow from the finite number of rescatterings in a two-dimensional massless transport model
• Collectivity in large and small systems formed in ultrarelativistic collisions
• Primordial non-Gaussianity in heavy-ion collisions
• Higher-order moments of the elliptic flow distribution in PbPb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Impact parameter dependence of anisotropic flow: Bayesian reconstruction in ultracentral nucleus-nucleus collisions
• Bayesian reconstruction of anisotropic flow fluctuations at fixed impact parameter
• Scaling approach to rigid and soft nuclear deformation through flow fluctuations in high-energy nuclear collisions
• A Novel Approach to Fast Calculation of High-Order Q-Cumulants