Exclusive production of rho^0 rho^0 pairs in gamma-gamma collisions at RHIC

Abstract

We discuss exclusive electromagnetic production of two neutral $\rho$ mesons in coherent photon-photon processes in ultrarelativistic heavy-ion collisions. The cross section is calculated in the equivalent photon approximation (EPA). Both uncertainties of the flux factors and photon-photon cross sections are discussed in details. We show that inclusion of precise charge densities in nuclei is essential for realistic evaluations of the nuclear photon-photon cross sections. We find that the cross section, especially with realistic flux factors, is sensitive to low energy in the subsystem $\gamma \gamma \to {\rho }^0{\rho }^0$. The experimental data for the $\gamma \gamma \to {\rho }^0{\rho }^0$ cross section extracted from $e^{+}{e}^{-}$ collisions are parametrized and used to estimate the nucleus-nucleus cross section. In addition, we include vector-dominance-model(VDM)--Regge contribution which becomes important at large photon-photon energy. Large nuclear cross sections are obtained. We discuss a possibility of focusing on the large-energy component. We find that both ${\rho }^0$ mesons are produced predominantly at midrapidities and could be measured by the STAR collaboration at RHIC.

11 pages, 7 figures; reference added/corrected

References in corpus (2)

• The Physics of Ultraperipheral Collisions at the LHC
• Hard Pomeron-Odderon interference effects in the production of pi^+pi^- pairs in high energy gamma-gamma collisions at the LHC

Cited by in corpus (1)

• Production of Z^0 bosons with rapidity gaps: exclusive photoproduction in gamma p and p p collisions and inclusive double diffractive Z^0's