Comparison of the isolated direct photon cross sections in p(p)over-bar collisions at root s=1.8 TeV and root s=0.63 TeV

Comparison of the isolated direct photon cross sections in p(p)over-bar collisions at root s=1.8 TeV and root s=0.63 TeV

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 chromodynam...

Mô tả đầy đủ

Chi tiết về thư mục
Những tác giả chính: Acosta, D, Affolder, T, Akimoto, H, Albrow, MG, Ambrose, D, Amidei, D, Anikeev, K, Antos, J, Apollinari, G, Arisawa, T, Artikov, A, Asakawa, T, Ashmanskas, W, Azfar, F, Azzi-Bacchetta, P, Bacchetta, N, Bachacou, H, Badgett, W, Bailey, S, de Barbaro, P, Barbaro-Galtieri, A, Barnes, V, Barnett, B, Baroiant, S, Barone, M
Định dạng: Journal article
Ngôn ngữ:English
Được phát hành: 2002
Miêu tả
Tóm tắt: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. © 2002 The American Physical Society.

Những quyển sách tương tự