Left: trigger-normalized semi-inclusive recoil jet distributions with $R=0.4$ for ${\rm TT_{sig}}$ and ${\rm TT_{ref}}$-selected populations in pp collisions at $\s=5.02$ TeV; Right: ratio of the two distributions. The horizontal blue line indicates the fit to the ratio close to $p_{\rm T,\text{ch jet}}^{\rm reco}=0$ for the determination of $c_{\rm Ref}$, the value of which is also given in the figures.