Measurement of the top quark pair production cross section in PbPb collisions at sNN=5.36 TeV


Belyaev A., Gevorgyan A., Hayrapetyan A., Tumasyan A., Adam W., Benato L., ...Daha Fazla

Journal of High Energy Physics, cilt.2026, sa.8, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 2026 Sayı: 8
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1007/jhep08(2026)054
  • Dergi Adı: Journal of High Energy Physics
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, INSPEC, MathSciNet, zbMATH, Directory of Open Access Journals, Academic Search Ultimate (EBSCO), Technology Collection (ProQuest)
  • Anahtar Kelimeler: Heavy Ion Experiments, Top Physics
  • Yozgat Bozok Üniversitesi Adresli: Evet

Özet

The inclusive cross section for top quark pair (tt¯) production in lead-lead (PbPb) collisions is reported for the first time at a center-of-mass energy per nucleon pair of 5.36 TeV. The analysis uses data corresponding to an integrated luminosity of 1.58 nb−1 collected by the CMS experiment at the CERN LHC in 2023. The tt¯ production cross section, σtt¯=3.42−0.51+0.54stat−0.43+0.50systμb, is measured in dilepton final states using a fit to a multivariate discriminator that combines the decay electron and muon kinematic properties with the multiplicity of bottom quark jets. The result is consistent with perturbative quantum chromodynamics calculations at next-to-next-to-leading order (NNLO) accuracy employing several nuclear parton distribution functions. In addition, the Drell–Yan production cross section (σDY) for dilepton masses above 10 GeV and the ratio of tt¯ to DY cross sections Rtt¯/DY are found to be compatible with the NNLO predictions. The observables σtt¯, σDY, and Rtt¯/DY are measured separately for central and semicentral PbPb collisions to investigate for the first time the dependence of top quark production on the collision impact parameter.