Observation of top quark production in proton-nucleus collisions

• Main Authors: Sirunyan, A. M., Tumasyan, A. R., Adam, Wolfgang, Asilar, Ece, Bergauer, Thomas, Brandstetter, Johannes, Md. Ali, Mohd. Adli
• Format: Article
• Language: English; English
• Published: American Physical Society 2017
• Subjects: Q Science (General); QC Physics
• Online Access: http://irep.iium.edu.my/63045/1/63045_Observation%20of%20Top%20Quark%20Production%20_article.pdf; http://irep.iium.edu.my/63045/2/63045_Observation%20of%20Top%20Quark%20Production%20_scopus.pdf; http://irep.iium.edu.my/63045/; https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.119.242001

The first observation of top quark production in proton-nucleus collisions is reported using proton-lead data collected by the CMS experiment at the CERN LHC at a nucleon-nucleon center-of-mass energy of sNN=8.16 TeV. The measurement is performed using events with exactly one isolated electron or muon candidate and at least four jets. The data sample corresponds to an integrated luminosity of 174 nb-1. The significance of the tt signal against the background-only hypothesis is above 5 standard deviations. The measured cross section is σtt=45±8 nb, consistent with predictions from perturbative quantum chromodynamics.