# Relative flow fluctuations as a probe of initial state fluctuations

Abstract : Elliptic flow, $v_2$, and triangular flow, $v_3$, are to a good approximation linearly proportional to the corresponding spatial anisotropies of the initial density profile, $\varepsilon_2$ and $\varepsilon_3$. Using event-by-event hydrodynamic simulations, we point out when deviations from this linear scaling are to be expected. When these deviations are negligible, relative $v_n$ fluctuations are equal to relative $\varepsilon_n$ fluctuations, and one can directly probe models of initial conditions using ratios of cumulants, for instance $v_n\{4\}/v_n\{2\}$. We argue that existing models of initial conditions tend to overestimate flow fluctuations in central Pb+Pb collisions, and to underestimate them in peripheral collisions. We make predictions for $v_3\{6\}$ in noncentral Pb+Pb collisions, and for $v_3\{4\}$ and $v_3\{6\}$ in high-multiplicity p+Pb collisions.
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Preprints, Working Papers, ...
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Cited literature [33 references]

https://hal-cea.archives-ouvertes.fr/cea-01472192
Contributor : Emmanuelle de Laborderie <>
Submitted on : Monday, February 20, 2017 - 3:57:18 PM
Last modification on : Wednesday, April 14, 2021 - 12:12:48 PM
Long-term archiving on: : Sunday, May 21, 2017 - 2:49:12 PM

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1702.01730.pdf
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### Identifiers

• HAL Id : cea-01472192, version 1
• ARXIV : 1702.01730

### Citation

Giuliano Giacalone, Jacquelyn Noronha-Hostler, Jean-Yves Ollitrault. Relative flow fluctuations as a probe of initial state fluctuations. 2017. ⟨cea-01472192⟩

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