A Review of Elliptic Flow of Light Nuclei in Heavy-Ion Collisions at RHIC and LHC Energies

Md Rihan Haque,Bedangadas Mohanty,Chitrasen Jena

doi:10.1155/2017/1248563

Abstract

We present a review of the measurements of elliptic flow (v2) of light nuclei (d, d¯, t, He3, and He¯3) from the RHIC and LHC experiments. Light (anti)nuclei v2 have been compared with that of (anti)proton. We observed a similar trend in light nuclei v2 to that in identified hadron v2 with respect to the general observations such as pT dependence, low pT mass ordering, and centrality dependence. We also compared the difference of nuclei and antinuclei v2 with the corresponding difference of v2 of proton and antiproton at various collision energies. Qualitatively they depict similar behavior. We also compare the data on light nuclei v2 to various theoretical models such as blast-wave and coalescence. We then present a prediction of v2 for He3 and He4 using coalescence and blast-wave models.

Highlights

The main goals of high energy heavy-ion collision experiments have primarily been to study the properties of Quark Gluon Plasma (QGP) and the other phase structures in the QCD phase diagram [1,2,3,4,5,6,7,8,9,10,11]
The quark coalescence as a mechanism of hadron production at intermediate transverse momentum has been well established by studying the number of constituent quarks (NCQ) scaling for V2 of identified hadrons measured at RHIC [37,38,39,40,41,42,43,44,45]
The pT dependence of V2 of d, d, t, 3He, and 3He is shown for 0–80% centrality in STAR, 20–60% centrality in PHENIX, and 30–40% centrality in ALICE

Summary

Introduction

The main goals of high energy heavy-ion collision experiments have primarily been to study the properties of Quark Gluon Plasma (QGP) and the other phase structures in the QCD phase diagram [1,2,3,4,5,6,7,8,9,10,11]. It is expected that high energy heavy-ion collisions will allow studying the production of light nuclei such as d, t, 3He, and their corresponding antinuclei. The first mechanism is thermal production of nucleusantinucleus pairs in elementary nucleon-nucleon or partonparton interactions [15,16,17,18,19,20,21] Due to their small (∼ few MeV) binding energies, the directly produced nuclei or antinuclei are likely to break up in the medium before escaping. In case of nucleon coalescence, momentum space distributions of both the constituents (nucleons) and the products (nuclei) are measurable in heavy-ion collision experiments. It provides an excellent opportunity to understand the mechanism of coalescence at work in high energy heavy-ion collisions

Methods

Results

Conclusion