Measurement of the top-quark mass using decays with a J/ψ meson at √s=13 TeV with the ATLAS detector



Aad, G, Aakvaag, E, Abbott, B, Abdelhameed, S, Abeling, K, Abicht, NJ, Abidi, SH, Aboelela, M, Aboulhorma, A, Abramowicz, H
et al (show 2923 more authors) (2026) Measurement of the top-quark mass using decays with a J/ψ meson at √s=13 TeV with the ATLAS detector JOURNAL OF HIGH ENERGY PHYSICS, 2026 (4). ISSN 1126-6708, 1029-8479

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Abstract

The top-quark mass is measured using top-quark decays producing an isolated lepton and J/ψ meson reconstructed in its μ+μ− decay mode. The data sample was recorded with the ATLAS detector in proton-proton collisions at a centre-of-mass energy of s=13 TeV during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb−1. The measurement is based on the invariant mass m(ℓμ+μ−) of the system made of the isolated lepton ℓ from the W boson decay and the non-isolated μ+μ− pair from a J/ψ decay of a b-hadron, exploiting its sensitivity to the top-quark mass. An unbinned maximum-likelihood fit to the m(ℓμ+μ−) distribution is performed to extract the top-quark mass. The top-quark mass is measured to be m<inf>top</inf> = 172.17 ± 0.80 (stat) ± 0.81 (syst) ± 1.07 (recoil) GeV, with a total uncertainty of 1.56 GeV. The third uncertainty arises from changing the dipole parton shower gluon-recoil scheme used in top-quark decays.

Item Type: Article
Uncontrolled Keywords: Hadron-Hadron Scattering, Top Physics
Divisions: Faculty of Science & Engineering
Faculty of Science & Engineering > School of Physical Sciences
Faculty of Science & Engineering > School of Physical Sciences > Physics
Depositing User: Symplectic Admin
Date Deposited: 15 Jun 2026 14:45
Last Modified: 15 Jun 2026 14:45
DOI: 10.1007/JHEP04(2026)099
Open Access URL: https://link.springer.com/article/10.1007/JHEP04(2...
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3198930
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