χ and J/ψ production in double-diffractive proton-proton collisions

It was pointed out earlier, that double-diffractive J/ψ production may serve as an important instrument to probe the odderon. However, double-diffractive production of χ′s due to pomeron-pomeron fusion, subsequently decaying into J/ψ + γ is a possibly troublesome background. Therefore, we calculate the corresponding differential cross sections for χ production and compare the obtained J/ψ yield to the rate of J/ψ directly produced by pomeron-pomeron fusion. We show that χ production is strongly suppressed. Hence, we conclude that double-diffractive exclusive J/ψ production could be the ideal process to search for the odderon.