Left: the D$^0$-decay candidate invariant-mass distribution for $10< p_{\rm T}^{\rm ch jet} < 20$ GeV/$c$ and $8 < p_{\rm T}^{\rm D^0} < 12$ GeV/$c$. The total fit function of the signal and background is represented by the blue line. The background fit function is represented by the red line. Right: the raw yields of the D$^0$-tagged jets as a function of $\Delta R_{\rm STD - D^0}$ in the signal region and sideband region.