A^{1/3}$) and term $a$ includes all contributions from the [*localized*]{} hard scattering as well as those suppressed by high power of $1/Q^2$. In principle, the parameter $a$ in Eq. (\[BA13\]) can also depend on the atomic weight $A$. But, as we will explain below, its dependence on $A$ should be very weak (e.g., $A^{\alpha}$ dependence with $\alpha \simeq 
\pm 0.02$). In this paper, we are interested in the second term in Eq. (\[BA13\]), and we show that experimental measurement of the constant $b$ in Eq. (\[BA13\]) will provide direct information on the quark-gluon correlation functions shown in Eq. (\[T4qA\]).

To derive explicit expressions for the $a$ and $b$ in Eq. (\[BA13\]), we expand both numerator and the denominator in Eq. (\[LTavg\]) in terms of a power series of $1/Q^2$. In addition to the terms of leading power, we keep only the power suppressed terms that are explicitly enhanced by a factor $A^{1/3}$. Since the denominator, $d\sigma_{eA\rightarrow eX}/dx_B dQ^2$, is the total inclusive DIS cross section, the operator product expansion (OPE) allows us to expand it in terms of the power series of $1/Q^2$ [@CFP; @Ellis], $$\begin{aligned}
\frac{d\sigma_{eA\rightarrow eX}}{dx_B dQ^2} &=& 
\sum_a \int dx\, \phi_{a/A}(x,\mu^2)\,
       \frac{d\hat{\sigma}^{(0)}_{ea\rightarrow eX}}{dx_B dQ^2}
       \left(x_B/x,\mu^2/Q^2,\alpha_s(\mu^2)\right)
\left[\, 1 