Classical gluon production amplitude in heavy-ion collisions

Giovanni Antonio Chirilli

doi:10.1051/epjconf/201611202004

Giovanni Antonio Chirilli

Open Access

https://doi.org/10.1051/epjconf/201611202004

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Abstract

The initial condition for the formation of the Quark-Gluon Plasma, the distribution of quarks and gluons produced in the initial stages of nuclear collisions, is the fundamental building block of heavy-ion theory. In the framework of saturation physics and Wilson lines formalism we calculate the scattering amplitude, beyond the leading order, of the classical gluon produced in heavy-ion collisions.known as the initial condition of the Quark-Gluon Plasma formation, is the fundamental building block of heavy-ion theory.

Highlights

To understand the initial stages of nuclear collisions and the formation of quark gluon plasma, one has to study the dynamics of collisions from first principle in Quantum Chromodynamic (QCD)
The diagrams that contribute at this order may be divided in three classes as shown in Fig. 2 [2]
The results presented here represent a first step toward obtaining the single inclusive gluon production cross-section for heavy-light ions collisions at the classical level beyond the LO

Summary

Introduction

To understand the initial stages of nuclear collisions and the formation of quark gluon plasma, one has to study the dynamics of collisions from first principle in Quantum Chromodynamic (QCD). To this end, we calculate the scattering amplitude, beyond the leading order, of the classical gluon produced in Nucleus-Nucleus collisions. The saturation scale of nucleus A1, which is proportional to its atomic number, Q2s1 ∼ α2s A1s1/3 is much smaller the saturation scale of the large nucleus, Q22s ∼ α2s A12/3. If we consider a particle propagation through a large nucleus with atomic number A, with good probability, will encounter, along its path, A1/3 nucleons. In proportional our case we tohaαve2s Aα12/s3A12a/n3d since A ∼ 1 for is a large the larger nucleus (the target) which in the boosted Lorentz frame reduces to a shock-wave (represented as a red stripe in all diagrams below), and α2s A11/3 ≤ 1 for the smaller one (the projectile)

From proton-Nucleus to Heavy-light Ion Collisions

Gauge invariance

Conclusion and Outlook