Identification of b-quark jets with the CMS experiment
Identification of b-quark jets with the CMS experiment
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DOI：
10.1088/1748-0221/8/04/p04013
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发表时间：
2013-04-01
影响因子：
1.3
通讯作者：
Swanson, J.
中科院分区：
文献类型：
--
作者：
Chatrchyan, S.;Khachatryan, V.;Swanson, J.
在大型强子对撞机中，确定源自b夸克的喷流对于寻找新的物理学和测量标准模型过程非常重要。CMS开发了多种算法，根据诸如带电粒子轨迹的冲击参数、重构衰变顶点的性质、存在或不存在轻子或它们的组合等变量来选择b-夸克喷流。这些算法的性能已经用LHC中质子-质子碰撞的数据进行了测量，并与基于模拟的预期进行了比较。本研究使用的数据记录于2011年，根s = 7TeV，总积分光度为5.0 fb（-1）。标记b夸克喷流的效率已经在多喷流和t夸克对产生的事件中得到了测量。在多射流事件中，CMS在轻粒子误认率为10%的情况下实现了85%的b射流标记效率。对于需要更高纯度的分析，错误识别概率仅为1.5%，b-jet标记效率为70%。
At the Large Hadron Collider, the identification of jets originating from b quarks is important for searches for new physics and for measurements of standard model processes. A variety of algorithms has been developed by CMS to select b-quark jets based on variables such as the impact parameters of charged-particle tracks, the properties of reconstructed decay vertices, and the presence or absence of a lepton, or combinations thereof. The performance of these algorithms has been measured using data from proton-proton collisions at the LHC and compared with expectations based on simulation. The data used in this study were recorded in 2011 at root s = 7TeV for a total integrated luminosity of 5.0 fb(-1). The efficiency for tagging b-quark jets has been measured in events from multijet and t-quark pair production. CMS has achieved a b-jet tagging efficiency of 85% for a light-parton misidentification probability of 10% in multijet events. For analyses requiring higher purity, a misidentification probability of only 1.5% has been achieved, for a 70% b-jet tagging efficiency.