Initial state fluctuations and final state correlations: Status and open questions

TL;DR

This paper reviews the current understanding of initial state fluctuations and their impact on final state correlations in relativistic heavy-ion collisions, highlighting recent progress, open questions, and future research directions.

Contribution

It provides a comprehensive summary of recent theoretical and experimental work on initial state fluctuations and their propagation in heavy-ion collisions.

Findings

Significant progress in understanding fluctuation propagation

Identification of key open questions in the field

Workshop outcomes guiding future research

Abstract

The recent appreciation of the importance of event-by-event fluctuations in relativistic heavy-ion collisions has lead to a large amount of diverse theoretical and experimental activity. In particular, there is significant interest in understanding the fluctuations in the initial stage of a collision, how exactly these fluctuations are propagated through the system evolution, and how they are manifested in correlations between measured particles. In order to address these questions a workshop was organized on "Initial State Fluctuations and Final State Correlations", held at ECT* in Trento, Italy during the week of 2--6 July, 2012. The goal was to collect recent work in order to provide a coherent picture of the current status of our understanding, to identify important questions that remain open, and to set a course for future research. Here we report the outcome of the presentations and discussions, focusing on the most important conclusions.