A global QCD study of direct photon production
- Michigan State Univ., East Lansing, MI (United States)
- Fermi National Accelerator Lab., Batavia, IL (United States)
- Argonne National Lab., IL (United States)
- Florida State Univ., Tallahassee, FL (United States)
A global QCD analysis of the direct photon production process from both fixed target and collider experiments is presented. These data sets now completely cover the parton x range from 0.01 to 0.6, thereby providing a stringent test of perturbative QCD and parton distributions. Previous detailed studies of direct photons emphasized fixed target data. The authors find most data sets have a steeper p{sub t} distribution than the QCD prediction. Neither global fits with new parton distributions nor improved photon fragmentation functions can resolve this problem since the deviation occurs at different x values for experiments at different energies. A more likely explanation is the need for additional broadening of the k{sub t} of the initial state partons. The magnitude and the possible physical origin of this effect are investigated and discussed.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States); National Science Foundation, Washington, DC (United States); Texas National Research Lab. Commission, De Soto, TX (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 521630
- Report Number(s):
- ANL-HEP-PR-95-24; MSU-HEP-41027; ON: DE97008524; IN: CDF/PUB/JET/PUBLIC/2979; CTEQ-407; TRN: 97:016623
- Resource Relation:
- Other Information: PBD: Jan 1995
- Country of Publication:
- United States
- Language:
- English
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