Analyzing the Power Spectrum of the Little Bangs

TL;DR

This paper draws an analogy between heavy-ion collision data and the Cosmic Microwave Background, analyzing the power spectrum to infer properties like the mean-free-path of particles.

Contribution

It introduces a novel method of extracting a power spectrum from heavy-ion collision data and defines a transfer-function to study the suppression of higher modes.

Findings

Higher n terms are suppressed in the power spectrum.

The suppression provides insights into the mean-free-path.

Estimated mean-free-path is larger than previous estimates.

Abstract

In this talk we discuss the analogy between data from heavy-ion collisions and the Cosmic Microwave Background. We identify p_T correlations data as the heavy-ion analogy to the CMB and extract a power-spectrum from the heavy-ion data. We define the ratio of the final state power-spectrum to the initial coordinate-space eccentricity as the transfer-function. From the transfer-function we find that higher $n$ terms are suppressed and we argue that the suppression provides information on length scales like the mean-free-path. We make a rough estimate of the mean-free-path and find that it is larger than estimates based on the centrality dependence of v_2.