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arXiv · 1712.03912

Study of the sensitivity of observables to hot spot size in heavy ion collisions

Fernando G. Gardim·Frederique Grassi·Pedro Ishida·Matthew Luzum·Pablo S. Magalhães·Jacquelyn Noronha-Hostler
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Abstract

An open question in the field of heavy-ion collisions is to what extent the size of initial inhomogeneities in the system affects measured observables. Here we present a method to smooth out these inhomogeneities with minimal effect on global properties, in order to quantify the effect of short-range features of the initial state. We show a comparison of hydrodynamic predictions with original and smoothened initial conditions for four models of initial conditions and various observables. Integrated observables (integrated $v_n$, scaled $v_n$ distributions, normalized symmetric cumulants, event-plane correlations) as well as most differential observables ($v_n(p_T)$) show little dependence on the inhomogeneity sizes, and instead are sensitive only to the largest-scale geometric structure. However other differential observables such as the flow factorization ratio and sub-leading principal components are more sensitive to the granularity and could be a good tool to probe the short-scale dynamics of the initial stages of a heavy-ion collision, which are not currently well understood.

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Fernando G. Gardim, Frederique Grassi, Pedro Ishida, Matthew Luzum, Pablo S. Magalhães, Jacquelyn Noronha-Hostler. 2017-12-11. Study of the sensitivity of observables to hot spot size in heavy ion collisions. https://doi.org/10.1103/physrevc.97.064919

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