Measurement of the t(t)over-bar production cross-section using e mu events with b-tagged jets in pp collisions at root s=7 and 8 TeV with the ATLAS detector
文献类型：期刊论文
| 作者 | ATLAS collaboration |
| 刊名 | EUROPEAN PHYSICAL JOURNAL C
 |
| 出版日期 | 2014 |
| 卷号 | 74期号:10 |
| 关键词 | HADRON COLLIDERS TOP-QUARK PARTON DISTRIBUTIONS PAIR PRODUCTION LHC SUPERSYMMETRY MASSES RESUMMATION PHYSICS WEAK |
| 通讯作者 | Aad, G (reprint author), Univ Adelaide, Dept Phys, Adelaide, SA, Australia. |
| 英文摘要 | The inclusive top quark pair (t (t) over tilde) production cross-section sigma(t (t) over bar) has been measured in proton-proton collisions at root s = 7 TeV and root s = 8 TeV with the ATLAS experiment at the LHC, using t (t) over bar events with an opposite-charge e mu pair in the final state. The measurement was performed with the 2011 7 TeV dataset corresponding to an integrated luminosity of 4.6 fb(-1) and the 2012 8 TeV dataset of 20.3 fb(-1). The numbers of events with exactly one and exactly two b-tagged jets were counted and used to simultaneously determine sigma(t (t) over bar) and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section was measured to be: sigma(t (t) over bar) = 182.9 +/- 3.1 +/- 4.2 +/- 3.6 +/- 3.3 pb (root s = 7 TeV) and sigma(t (t) over bar) = 242.4 +/- 1.7 +/- 5.5 +/- 7.5 +/- 4.2 pb (root s = 8 TeV), where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, knowledge of the integrated luminosity and of the LHC beam energy. The results are consistent with recent theoretical QCD calculations at next-to-next-to-leading order. Fiducial measurements corresponding to the experimental acceptance of the leptons are also reported, together with the ratio of cross-sections measured at the two centre-of-mass energies. The inclusive cross-section results were used to determine the top quark pole mass via the dependence of the theoretically predicted cross-section on m(t)(pole) giving a result of m(t)(pole) = 172.9(-2.6)(+2.5) GeV. By looking for an excess of t (t) over bar production with respect to the QCD prediction, the results were also used to place limits on the pair-production of supersymmetric top squarks (t) over tilde (1) with masses close to the top quarkmass, decaying via (t) over tilde (1) -> t (chi) over tilde (0)(1) 1 to predominantly right-handed top quarks and a light neutralino (chi) over tilde (0)(1) 1, the lightest supersymmetric particle. Top squarks with masses between the top quark mass and 177 GeV are excluded at the 95% confidence level. |
| 学科主题 | Physics |
| 类目[WOS] | Physics, Particles & Fields |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000346526400001 |
| 公开日期 | 2016-02-26 |
| 源URL | [http://ir.ihep.ac.cn/handle/311005/213836]  |
| 专题 | 高能物理研究所_实验物理中心 |
| 作者单位 | 中国科学院高能物理研究所 |
| 推荐引用方式 GB/T 7714 | ATLAS collaboration. Measurement of the t(t)over-bar production cross-section using e mu events with b-tagged jets in pp collisions at root s=7 and 8 TeV with the ATLAS detector[J]. EUROPEAN PHYSICAL JOURNAL C,2014,74(10). |
| APA | ATLAS collaboration.(2014).Measurement of the t(t)over-bar production cross-section using e mu events with b-tagged jets in pp collisions at root s=7 and 8 TeV with the ATLAS detector.EUROPEAN PHYSICAL JOURNAL C,74(10). |
| MLA | ATLAS collaboration."Measurement of the t(t)over-bar production cross-section using e mu events with b-tagged jets in pp collisions at root s=7 and 8 TeV with the ATLAS detector".EUROPEAN PHYSICAL JOURNAL C 74.10(2014). |
入库方式： OAI收割
来源：高能物理研究所
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