Measurement of top quark polarization in top-antitop events from proton-proton collisions at vs=7 TeV using the ATLAS detector.
Measurement of top quark polarization in top-antitop events from proton-proton collisions at vs=7 TeV using the ATLAS detector.
复制标题
使用 ATLAS 探测器测量 vs=7 TeV 质子-质子碰撞的顶反顶事件中的顶夸克偏振。
DOI：
10.1103/physrevlett.111.232002
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发表时间：
2013
影响因子：
8.6
通讯作者：
Aad G
中科院分区：
文献类型：
--
作者：
Aad G
这封信介绍了利用大型强子对撞机ATLAS探测器在sqrt（s）= 7 TeV时记录的4.7 fb^-1质子-质子碰撞数据，测量顶夸克-反顶夸克对事件中顶夸克的极化。包含一个或两个孤立的轻子（电子或μ子）和喷流的最终状态被认为是。假设顶夸克极化是由CP守恒（CPC）或CP破坏（CPV）产生过程引入的，对轻子自旋分析本领与顶夸克极化的乘积alpha_1P进行了两次测量.实验测量值α_1 P_CPC = -0.035 +/-0.014（stat）+/-0.037（syst）和α_1 P_CPV = 0.020 +/-0.016（stat）+0.013 -0.017（syst），与标准模型中顶夸克极化可忽略的预言符合得很好。
This Letter presents measurements of the polarization of the top quark in top-antitop quark pair events, using 4.7 fb^-1 of proton-proton collision data recorded with the ATLAS detector at the Large Hadron Collider at sqrt(s) = 7 TeV. Final states containing one or two isolated leptons (electrons or muons) and jets are considered. Two measurements of alpha_l P, the product of the leptonic spin-analyzing power and the top quark polarization, are performed assuming that the polarization is introduced by either a CP conserving (CPC) or a CP violating (CPV) production process. The measurements obtained, alpha_l P_CPC = -0.035 +/- 0.014 (stat) +/- 0.037 (syst) and alpha_l P_CPV = 0.020 +/- 0.016 (stat) +0.013 -0.017 (syst), are in good agreement with the Standard Model prediction of negligible top quark polarization.