Gluon correlations from a Glasma flux-tube model compared to measured hadron correlations on transverse momentum $\bf (p_t,p_t)$ and angular differences $\bf (\eta_\Delta,\phi_\Delta)$

TL;DR

This study tests the Glasma flux-tube model's explanation for long-range correlations in high-energy nuclear collisions and finds it inconsistent with experimental data, favoring a two-component fragmentation model instead.

Contribution

The paper critically evaluates the Glasma flux-tube model against experimental data and demonstrates its shortcomings compared to a two-component fragmentation approach.

Findings

Glasma model contradicts measured hadron yields and correlations.

Two-component fragmentation model aligns well with most data.

The origin of eta elongation remains unresolved.

Abstract

A Glasma flux-tube model has been proposed to explain strong elongation on pseudorapidity $\eta$ of the same-side 2D peak in minimum-bias angular correlations from $\sqrt{s_{NN}} = 200$ GeV \auau collisions. The same-side peak or "soft ridge" is said to arise from coupling of flux tubes to radial flow. Gluons radiated transversely from flux tubes are boosted by radial flow to form a narrow structure or ridge on azimuth. In this study we test the conjecture by comparing predictions for particle production, spectra and correlations from the Glasma model and conventional fragmentation processes with measurements. We conclude that the Glasma model is contradicted by measured hadron yields, spectra and correlations, whereas a two-component model of hadron production, including minimum-bias parton fragmentation, provides a quantitative description of most data, although $\eta$ elongation remains unexplained.