Exclusive Vector Meson Production in Relativistic Heavy Ion Collisions

TL;DR

This paper discusses the high rates of exclusive vector meson production in relativistic heavy ion collisions at RHIC and LHC, highlighting their potential as vector meson factories and analyzing the underlying photon-Pomeron interactions.

Contribution

It introduces a method to estimate exclusive vector meson production rates in heavy ion collisions using photonuclear cross sections scaled from $\gamma p$ data.

Findings

High production rates of vector mesons at RHIC and LHC.

Potential use of heavy ion colliders as vector meson factories.

Analysis of the interplay between photonuclear and two-photon interactions.

Abstract

Exclusive vector meson production reactions such as $Au + Au \to Au + Au + V$, where $V=\rho, \omega, \phi$ or $J/\psi$ can proceed through photon-Pomeron and photon-meson interactions. Photons from the electromagnetic field of one nucleus interact coherently with the other nucleus. Photonuclear cross sections are scaled from $\gamma p$ data, and convoluted with the photon spectrum to find the exclusive rates. The cross sections at the RHIC and LHC heavy ion colliders are huge, 10% of the total hadronic cross section at RHIC, and 50% at LHC. These accelerators may be useful as vector meson factories. With iodine beams at RHIC, 640 $\rho$ are produced each second (10^{10}/year); with calcium at the LHC the rate is 240 kHz. The $\phi$ rates are 39 Hz at RHIC and 15 kHz at LHC, while the $J/\psi$ rate is 0.3 Hz at RHIC and 780 Hz at the LHC. Because of the coherent couplings, the reactions kinematics are similar to coherent two-photon interactions; we discuss the interplay between the two reactions.