Measurement of the top quark mass from top quark produced in proton-proton collisions at $\sqrt{s}$ = 13 TeV that decay to dimuon via a J/$\psi$

The top quark mass is measured using "t\overline{t} \rightarrow" lepton + J/$\psi$($\rightarrow$$\mu$$^{+}$$\mu$$^{-}$ events, using proton-proton collision data collected by the ATLAS detector at a $\sqrt{s}$ = 13 TeV, during 2015-2018. The data corresponds to a total integrated luminosity of 139.0 fb$^{-1}$. This lepton + J/$\psi$ channel is statistically limited due to the low branching ratio of the $b$ $\rightarrow$ J/$\psi$ $\rightarrow$ $\mu$$^{+}$$\mu$$^{-}$. The top quark mass is measured from template fits over the m(lepton,J/$\psi$) distribution. The top quark mass is measured to be 172.03 $\pm$ 0.76 (stat) $\pm$ 2.14 (syst) GeV.