The paper "Measurement of the top-quark mass using decays with a J/ψ meson at √s = 13 TeV with the ATLAS detector ", to which Haruka Asada has contributed as the main author, was published in the Journal of High Energy Physics.

This paper reported a measurement of the top-quark mass using top-quark events containing J/ψ → μμ in the decay chain. The analysis exploits the correlation between the top-quark mass and the kinematic properties of charged leptons in the decay chain, which can be reconstructed with relatively high precision. This approach is expected to reduce the systematic uncertainties associated with jet reconstruction that dominate conventional measurements. On the other hand, the analysis faces several challenges. The branching fraction of the signal process is small, requiring dedicated strategies to obtain a sufficient number of signal events. In addition, the measurement is particularly sensitive to uncertainties in the simulation modeling. The developed analysis method was applied to proton–proton collision data collected by the ATLAS experiment during Run 2 of the LHC at a center-of-mass energy of √s = 13 TeV, corresponding to an integrated luminosity of 140 fb^-1. The resulting top-quark mass was measured to be m_top = 172.17 ± 0.80 (stat) ± 0.81 (syst) ± 1.07 (recoil) GeV. The third uncertainty corresponds to the systematic uncertainty associated with gluon-recoil modeling. The measured central value is consistent with previous measurements. By achieving a statistical precision comparable to that of earlier studies while reducing the jet-reconstruction uncertainty to below 100 MeV, this analysis provides the first measurement in this channel with the potential to contribute to the global top-quark mass combination. As one of the principal analysts, she contributed to the efficient production of simulation samples, the optimization of the fitting procedure, and the development of improved methods for evaluating systematic uncertainties.

You can find more information on the following paper.
Paper information:
G. Aad et al., (The ATLAS collaboration) "Measurement of the top-quark mass using decays with a J/ψ meson at √s = 13 TeV with the ATLAS detector "
[JHEP 04 (2026) 099. DOI:10.1007/JHEP04(2026)099]