Production of prompt electrons in the charm Pt region at s = 630 GeV

Abstract The production of prompt electrons at s = 630 GeV has been measured in the p t range 0.5–2.0 GeV/ c and the pseudorapidity range 1.1–1.7, using a ring imaging Cherenkov (RICH) counter installed in the UA2 experiment at the CERN pp collider. From our measurement of the electron/hadron ratio in the p t range 0.9–1.5 GeV/ c we conclude that the total charm production cross section at s = 630 GeV does not exceed 1.9 mb at 95% CL. As our best estimate we obtain σ tot (c c )=0.68 ±0.56 (stat.) ±0.25 (sys., exp.)±0.21 (sys., theory) mb.