标题： LEP中e+e- → gamma gamma过程中的非对易QED测试 显示英文标题

标题： Test of non-commutative QED in the process e+e- -> gamma gamma at LEP

摘要： 非对易QED将导致与标准模型的偏差，这取决于一个新的能量尺度Lambda_NC和由两个角度eta和xi定义的空间中的独特方向。在此分析中，eta被定义为独特方向与地球自转轴之间的角度。该理论对于e+e- -> gamma gamma过程的预测针对OPAL探测器的特定取向进行了评估，并与测量结果进行了比较。利用极角和方位角的分布来提取根据模型参数eta的不同而变化的能量尺度Lambda_NC的限制。在95%置信度下，发现Lambda_NC大于141 GeV，适用于所有eta和xi。如果存在可检测的信号，展示了总截面的时间依赖性可用于确定模型参数xi。这些是从e+e-对撞机实验中获得的非对易QED的第一个限制。 显示英文摘要

摘要： Non-commutative QED would lead to deviations from the Standard Model depending on a new energy scale Lambda_NC and a unique direction in space defined by two angles eta and xi. Here in this analysis eta is defined as the angle between the unique direction and the rotation axis of the earth. The predictions of such a theory for the process e+e- -> gamma gamma are evaluated for the specific orientation of the OPAL detector and compared to the measurements. Distributions of the polar and azimuthal scattering angles are used to extract limits on the energy scale Lambda_NC depending on the model parameter eta. At the 95% confidence level Lambda_NC is found to be larger than 141 GeV for all eta and xi. It is shown that the time dependence of the total cross-section could be used to determine the model parameter xi if there were a detectable signal. These are the first limits obtained on non-commutative QED from an e+e- collider experiment.