Observation of tt¯ Production in Pb+Pb Collisions at sNN=5.02 TeV with the ATLAS Detector
Skip to main content
eScholarship
Open Access Publications from the University of California

UC Irvine

UC Irvine Previously Published Works bannerUC Irvine

Observation of tt¯ Production in Pb+Pb Collisions at sNN=5.02 TeV with the ATLAS Detector

Published Web Location

http://doi.org/10.1103/physrevlett.134.142301
No data is associated with this publication.
Creative Commons 'BY-NC' version 4.0 license
Abstract

Top-quark pair production is observed in lead–lead (Pb+Pb) collisions at sNN=5.02  TeV at the Large Hadron Collider with the ATLAS detector. The data sample was recorded in 2015 and 2018, amounting to an integrated luminosity of 1.9  nb−1. Events with exactly one electron and one muon and at least two jets are selected. Top-quark pair production is measured with an observed (expected) significance of 5.0 (4.1) standard deviations. The measured top-quark pair production cross section is σtt¯=3.6 −0.9+1.0(stat) −0.5+0.8(syst)  μb, with a total relative uncertainty of 31%, and is consistent with theoretical predictions using a range of different nuclear parton distribution functions. The observation of this process consolidates the evidence of the existence of all quark flavors in the preequilibrium stage of the quark-gluon plasma at very high energy densities, similar to the conditions present in the early Universe. © 2025 CERN, for the ATLAS Collaboration 2025 CERN

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Item not freely available? Link broken?
Report a problem accessing this item