Yerevan Physics Institute, Yerevan, Armenia.
Phys Rev Lett. 2013 Jan 11;110(2):022003. doi: 10.1103/PhysRevLett.110.022003.
Evidence is presented for the associated production of a single top quark and W boson in pp collisions at sqrt[s]=7 TeV with the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 4.9 fb(-1). The measurement is performed using events with two leptons and a jet originated from a b quark. A multivariate analysis based on kinematic properties is utilized to separate the tt background from the signal. The observed signal has a significance of 4.0σ and corresponds to a cross section of 16(-4)(+5) pb, in agreement with the standard model expectation of 15.6±0.4(-1.2)(+1.0) pb.
研究结果表明,在 LHC 的 CMS 实验中,在质心系能量为 sqrt[s]=7 TeV 的 pp 碰撞中,单个顶夸克和 W 玻色子是同时产生的。分析所使用的数据对应的积分亮度为 4.9 fb(-1)。该测量是利用包含两个轻子和一个来源于 b 夸克的喷注的事例来完成的。利用基于运动学特性的多元分析方法将 tt 背景与信号区分开。观测到的信号有 4.0σ 的显著性,对应的截面为 16(-4)(+5) pb,与标准模型预期的 15.6±0.4(-1.2)(+1.0) pb 相符。