PPT Slide
Hard Color-Singlet Exchange
Count tracks and EM Calorimeter Towers in |h| < 1.0
(ET > 30 GeV, ?s = 1800 GeV)
Measured fraction (~1%) rises with initial quark content :
Consistent with a soft color rearrangement model preferring initial quark states
Inconsistent with two-gluon, photon, or U(1) models
Measure fraction of events
due to color-singlet exchange
Phys. Lett. B 440 189 (1998)