Photon-Photon and Photon-Hadron Physics at Relativistic Heavy Ion Colliders

TL;DR

This paper discusses the potential of relativistic heavy ion colliders like RHIC and LHC to study photon-photon and photon-hadron interactions, highlighting their high flux and the possibility of exploring new physics and vector meson production.

Contribution

It introduces the capabilities of RHIC and LHC for photon-induced collisions and their potential for new physics and vector meson studies.

Findings

RHIC will have the highest flux of quasireal photons in the GeV range.

LHC can access gamma-gamma interactions up to 100 GeV with higher luminosity.

Potential to study new physics and coherent vector meson production.

Abstract

Due to the coherence of all the protons in a nucleus, there are very strong electromagnetic fields of short duration in relativistic heavy ion collisions. They give rise to quasireal photon-photon and photon-nucleus collisions with a large flux. RHIC will begin its experimental program this year and such types of collisions will be studied experimentally at the STAR detector. RHIC will have the highest flux of (quasireal) photons up to now in the GeV region. At the LHC the invariant mass range available in gamma-gamma-interactions will be of the order of 100 GeV, i.e., in the range currently available at LEP2, but with a higher gamma-gamma-luminosity. Therefore one has there also the potential to study new physics. (Quasireal) photon-hadron (i.e., photon-nucleus) interactions can be studied as well, similar to HERA, at higher invariant masses. Vector mesons can be produced coherently through photon-Pomeron and photon-meson interactions in exclusive reactions such as A+A -> A+A+V, where A is the heavy ion and V=rho,omega,phi or J/Psi.