  Within the framework of a high-twist approach, we calculate the
next-to-leading order (NLO) perturbative QCD corrections to the transverse
momentum broadening in semi-inclusive hadron production in deeply inelastic
$e+A$ collisions, as well as lepton pair production in $p+A$ collisions. With
explicit calculations of both real and virtual contributions, we verify, for
the first time, the factorization theorem at twist 4 in NLO for the
nuclear-enhanced transverse momentum weighted differential cross section and
demonstrate the universality of the associated twist-4 quark-gluon correlation
function. We also identify the QCD evolution equation for the twist-4
quark-gluon correlation function in a large nucleus, which can be solved to
determine the scale dependence of the jet transport parameter in the study of
jet quenching.
