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arXiv · 1402.6680

A method for studying the rapidity fluctuation and decorrelation of harmonic flow in heavy-ion collisions

Jiangyong Jia·Peng Huo
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Abstract

An "event-shape twist" technique is proposed to study the longitudinal dynamics of harmonic flow, in particular the effects of rapidity fluctuation and event-plane decorrelation. This technique can distinguish between two types of rapidity decorrelation effects: a systematic rotation versus a random fluctuation of flow angles along the rapidity direction. The technique is demonstrated and the magnitude of the two decorrelation effects is predicted using the AMPT model via a single particle analysis and two-particle correlation analysis. An observed decorrelation can be attributed to a systematic rotation of event-plane angle along the pseudorapidity, consistent with a collective response to an initial state twist of the fireball proposed by Bozek {\it et.al.}. This rotation is also observed for several higher-order harmonics with the same sign and similar magnitudes.

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Jiangyong Jia, Peng Huo. 2014-09-11. A method for studying the rapidity fluctuation and decorrelation of harmonic flow in heavy-ion collisions. https://doi.org/10.1103/physrevc.90.034905

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