Evolution of the ratio of $\sqrt{ \llangle \Delta p_{\rm T1}\Delta p_{\rm T2} \rrangle }/{\llangle p_{\rm T} \rrangle }$ \ to results of a power-law fit to HIJING calculations: (left) \pp and \PbPb collisions at \snn = 5.02 TeV; (right) \pp collisions at \snn = 5.02 TeV and \XeXe collisions at \snn = 5.44 TeV. The power-law fit was performed on correlator values obtained with HIJING for \PbPb\ collisions at \snn = 5.02 TeV and \XeXe collisions at \snn = 5.44 TeV for left and right panel, respectively, as described in the text. Solid symbols represent the measured data reported in this work with statistical (vertical bars) and systematic (boxes) uncertainties. Calculations of the ratios obtained with HIJING and AMPT calculations are shown with shaded bands denoting their statistical uncertainty.