Coherent Photoproduction of Low-   p   T    Charmonium in Peripheral Heavy Ion Collisions within the Color Dipole Model

Gongming Yu,Quangui Gao,Qiang Hu,Liyuan Hu,Yushou Song,Haitao Yang,Yongping Fu,Yanbing Cai,Wei Li,Luca Stanco

doi:10.1155/2022/1561632

Abstract

We calculate the centrality dependence for coherent photoproduction of very low- p T J / ψ at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies within the impact parameter-dependent saturated color dipole model. By using the large equivalent photon fluxes, we present the differential cross-section of very low- p T J / ψ produced by coherent photonuclear in peripheral heavy ion collisions. The numerical results demonstrate that our calculation agrees with J / ψ data in peripheral heavy ion collisions at Relativistic Heavy Ion Collider (RHIC) energies.

Highlights

The Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) are the most powerful collider for the central and noncentral heavy ion collisions, offering a unique opportunity to study fundamental aspects of quantum electrodynamics (QED) and quantum chromodynamics (QCD)
A significant excess of J/ψ yield at very low transverse momenta has been observed by the ALICE cpoffilffilffiaffiffibffiffi oration in peripheral hadronic Pb-Pb collisions with sNN = 2:76 TeV at forward rapidity [30], and by thpe ffiSffiffiTffiffiffiAffi R collaboration in hadronic Au-Au pcoffiffiffilffilffiiffiffisions with sNN = 200 GeV and U-U collisions with sNN = 193 GeV at midrapidity [31, 32], that cannot be explained within the hadronic J/ψ production modified by the cold and hot medium effects
In order to present our results in a way that can be compared with STAR data from RHIC, we will study the invariant yield of very low-pT J/ψ production as the following: B

Summary

Introduction

The Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) are the most powerful collider for the central and noncentral heavy ion collisions, offering a unique opportunity to study fundamental aspects of quantum electrodynamics (QED) and quantum chromodynamics (QCD). A significant excess of J/ψ yield at very low transverse momenta has been observed by the ALICE cpoffilffilffiaffiffibffiffi oration in peripheral hadronic Pb-Pb collisions with sNN = 2:76 TeV at forward rapidity [30], and by thpe ffiSffiffiTffiffiffiAffi R collaboration in hadronic Au-Au pcoffiffiffilffilffiiffiffisions with sNN = 200 GeV and U-U collisions with sNN = 193 GeV at midrapidity [31, 32], that cannot be explained within the hadronic J/ψ production modified by the cold and hot medium effects It indicates that the significant excess maybe originated from the coherent photoproduction in hadronic heavy ion collisions (b < 2R).

General Formalism

Numerical Results

Conclusions