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 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 70 Issue: 7
  • Publication Date: 2004
  • Doi Number: 10.1103/physrevd.70.074008
  • Journal Name: PHYSICAL REVIEW D
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Istanbul University Affiliated: No

Abstract

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.