@article{6326fd4fdb044770af2c8158b28a89d4,
title = "Observation of (Formula presented) Production in Pb+Pb Collisions at (Formula presented) with the ATLAS Detector",
abstract = "Top-quark pair production is observed in lead-lead ((Formula presented)) collisions at (Formula presented) at the Large Hadron Collider with the ATLAS detector. The data sample was recorded in 2015 and 2018, amounting to an integrated luminosity of (Formula presented). 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 (Formula presented), 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.",
author = "{ATLAS Collaboration} and G. Aad and E. Aakvaag and B. Abbott and S. Abdelhameed and K. Abeling and Abicht, {N. J.} and Abidi, {S. H.} and M. Aboelela and A. Aboulhorma and H. Abramowicz and Y. Abulaiti and Acharya, {B. S.} and A. Ackermann and {Adam Bourdarios}, C. and L. Adamczyk and Addepalli, {S. V.} and Addison, {M. J.} and J. Adelman and A. Adiguzel and T. Adye and Affolder, {A. A.} and Y. Afik and Agaras, {M. N.} and A. Aggarwal and C. Agheorghiesei and F. Ahmadov and S. Ahuja and X. Ai and G. Aielli and A. Aikot and {Ait Tamlihat}, M. and B. Aitbenchikh and M. Akbiyik and {\AA}kesson, {T. P.A.} and Akimov, {A. V.} and D. Akiyama and Akolkar, {N. N.} and S. Aktas and {Al Khoury}, K. and Alberghi, {G. L.} and J. Albert and P. Albicocco and Albouy, {G. L.} and S. Alderweireldt and Alegria, {Z. L.} and M. Aleksa and Aleksandrov, {I. N.} and Connell, {S. H.} and N. Govender and L. Truong",
note = "Publisher Copyright: {\textcopyright} 2025 CERN, for the ATLAS Collaboration.",
year = "2025",
month = apr,
day = "11",
doi = "10.1103/PhysRevLett.134.142301",
language = "English",
volume = "134",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "14",
}