Direct photon cross section with conversions at CDF

Acosta D., Affolder T., Albrow M., Ambrose D., Amidei D., Anikeev K., ...More

PHYSICAL REVIEW D, vol.70, no.7, 2004 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 70 Issue: 7
  • Publication Date: 2004
  • Doi Number: 10.1103/physrevd.70.074008
  • Title of Journal : PHYSICAL REVIEW D


We present a measurement of the isolated direct photon cross section in p (p) over bar collisions at roots=1.8 TeV and \eta\<0.9 using data collected between 1994 and 1995 by the Collider Detector at Fermilab (CDF). The measurement is based on events where the photon converts into an electron-positron pair in the material of the inner detector, resulting in a two track event signature. To remove pi(0)-->gammagamma and eta-->gammagamma events from the data we use a new background subtraction technique which takes advantage of the tracking information available in a photon conversion event. We find that the shape of the cross section as a function of photon p(T) is poorly described by next-to-leading-order QCD predictions, but agrees with previous CDF measurements.