Central exclusive production of hadrons in CDF Available to Purchase

At the Fermilab Tevatron with $s = 900$ and 1960 GeV, we have studied exclusive double pomeron exchange in the Collider Detector at Fermilab, CDF. With ∼300,000 events we present the mass spectrum of two hadrons, h⁺h⁻, assumed to be pions, with |η(π)| < 1.3 and two rapidity gaps Δη > 4.6. The mass spectrum shows resonance structures, including f₀(980), f₂(1270), and f₀(1370). The cross section ratio 1960 GeV/900 GeV and the mean p_T (pair) show massdependent structures, even above M = 2 GeV where there are no established π⁺π⁻ resonances. The data extend above M = 5 GeV. We place an upper limit on exclusive χ_c0 →π⁺π⁻ and K⁺K⁻.