Monte Carlo comparisons of the top quark mass measurement techniques using kinematic constraints

A Monte Carlo study to compare the sensitivities of the top-quark mass-reconstruction methods using the b-quark decay as a kinematic constraint was performed. The top quark is reconstructed from its decay products, the W boson and the b-quark, and its mass can be obtained by using the 4-vector sum of their final states. However, missing neutrinos and the poor jet energy resolution makes the mass measurement biased and imprecise, always requiring further calibration, and dominates the systematic uncertainties. Several new ideas to increase the mass resolution by using the kinematic constraints of the b quark decays using a charm quark meson were suggested and performed to overcome such systematic limits. In this study, we compare three methods, one using J/ψ, another using D⁰, and the other using D* meson, by extracting their sensitivities to the top-quark mass, as well as their statistical advantages. This study is intended to set a priority in the real data analyses using a new data set from abundant tt¯ production in the Large Hadron Collider (LHC) Run 2.