Division of High Energy Physics, Department of Physics, University of Helsinki and Helsinki Institute of Physics, Helsinki, Finland.
Phys Rev Lett. 2011 Jun 17;106(24):241801. doi: 10.1103/PhysRevLett.106.241801. Epub 2011 Jun 15.
We report on the first measurement of the angular distributions of final state electrons in pp¯ → γ*/Z → e(+)e(-) + X events produced in the Z boson mass region at √s1.96 TeV. The data sample collected by the CDF II detector for this result corresponds to 2.1 fb(-1) of integrated luminosity. The angular distributions are studied as a function of the transverse momentum of the electron-positron pair and show good agreement with the Lam-Tung relation, consistent with a spin-1 description of the gluon, and demonstrate that, at high values of the transverse momentum, Z bosons are produced via quark-antiquark annihilation and quark-gluon Compton processes.
我们报告了在 √s1.96 TeV 的 Z 玻色子质量区域中，pp¯ → γ*/Z → e(+)e(-) + X 末态电子的角分布的首次测量结果。这个结果所对应的 CDF II 探测器的数据样本对应于 2.1 fb(-1)的积分亮度。角分布作为电子-正电子对的横动量的函数进行了研究，结果与 Lam-Tung 关系吻合较好，符合胶子的自旋-1 描述，并表明，在横动量较高的情况下，Z 玻色子是通过夸克-反夸克湮灭和夸克-胶子 Compton 过程产生的。
