Comparison of the isolated direct photon cross sections in pp̄ collisions at √s = 1.8 TeV and √s = 0.63 TeV

D. Acosta*, T. Affolder, H. Akimoto, M. G. Albrow, D. Ambrose, D. Amidei, K. Anikeev, J. Antos, G. Apollinari, T. Arisawa, A. Artikov, T. Asakawa, W. Ashmanskas, F. Azfar, P. Azzi-Bacchetta, N. Bacchetta, H. Bachacou, W. Badgett, S. Bailey, P. De BarbaroA. Barbaro-Galtieri, V. E. Barnes, B. A. Barnett, S. Baroiant, M. Barone, G. Bauer, F. Bedeschi, S. Belforte, W. H. Bell, G. Bellettini, J. Bellinger, D. Benjamin, J. Bensinger, A. Beretvas, J. P. Berge, J. Berryhill, A. Bhatti, M. Binkley, D. Bisello, M. Bishai, R. E. Blair, C. Blocker, K. Bloom, B. Blumenfeld, S. R. Blusk, A. Bocci, A. Bodek, G. Bolla, Y. Bonushkin, D. Bortoletto, J. Boudreau, A. Brandl, S. Van Den Brink, C. Bromberg, M. Brozovic, E. Brubaker, N. Bruner, J. Budagov, H. S. Budd, K. Burkett, G. Busetto, A. Byon-Wagner, K. L. Byrum, S. Cabrera, P. Calafiura, M. Campbell, W. Carithers, J. Carlson, D. Carlsmith, W. Caskey, A. Castro, D. Cauz, A. Cerri, A. W. Chan, P. S. Chang, P. T. Chang, J. Chapman, C. Chen, Y. C. Chen, M. T. Cheng, M. Chertok, G. Chiarelli, I. Chirikov-Zorin, G. Chlachidze, F. Chlebana, L. Christofek, M. L. Chu, J. Y. Chung, W. H. Chung, Y. S. Chung, C. I. Ciobanu, A. G. Clark, M. Coca, A. P. Colijn, A. Connolly, M. Convery, J. Conway, M. Cordelli, J. Cranshaw

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

68 Citations (Scopus)

Abstract

We have measured the cross sections d2σ/d P Tdη) for production of isolated direct photons in pp̄ collisions at two different center-of-mass energies, 1.8 TeV and 0.63 TeV, using the Collider Detector at Fermilab. The normalization of both data sets agrees with the predictions of quantum chromodynamics for a photon transverse momentum (PT) of 25 GeV/c, but the shapes versus photon PT do not. These shape differences lead to a significant disagreement in the ratio of cross sections in the scaling variable xT(≡ 2PT/√s). This disagreement in the xT ratio is difficult to explain with conventional theoretical uncertainties such as scale dependence and parton distribution parametrizations.

Original languageEnglish
Article number112003
JournalPhysical Review D
Volume65
Issue number11
DOIs
Publication statusPublished - 2002

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Fingerprint

Dive into the research topics of 'Comparison of the isolated direct photon cross sections in pp̄ collisions at √s = 1.8 TeV and √s = 0.63 TeV'. Together they form a unique fingerprint.

Cite this