Investigation of top mass measurements with the ATLAS detector at LHC
I. Borjanovic, I. Efthymiopoulos, F. Fassi, P. Grenier, P. Homola, V. Kostioukhine, R. Leitner, I. Mendas, D. Pallin, D. Popovic, P. Roy, V. Simak, L. Simic, G. Skoro, J. Valenta
TL;DR
This work comprehensively assesses ATLAS-based strategies for measuring the top-quark mass across dominant decay channels. It analyzes multiple methods—hadronic-top invariant mass, full kinematic fits, continuous jet definitions, high-pT event approaches, dilepton reconstruction, all-hadronic fits, and a J/psi–based indirect approach—each with distinct systematic profiles. The studies emphasize in-situ jet calibration, underlying-event subtraction, and robust kinematic constraints to control dominant systematics, projecting a total mt uncertainty at or near 1 GeV with about 10 fb^-1. The results highlight the complementary nature of the methods, showing consistent mass determinations and paving the way for a precise ATLAS combined top mass measurement in the early LHC program. Overall, the paper demonstrates that ATLAS can achieve a precise, cross-validated top mass with systematic-dominated uncertainties under control through diverse, well-calibrated analyses.
Abstract
Several methods for the determination of the mass of the top quark with the ATLAS detector at the LHC are presented. All dominant decay channels of the top quark can be explored. The measurements are in most cases dominated by systematic uncertainties. New methods have been developed to control those related to the detector. The results indicate that a total error on the top mass at the level of 1 GeV should be achievable.