  Transverse momentum broadening of fast partons propagating through a large
nucleus is proportional to the average color field strength in the nucleus. In
this work, the corresponding coefficient is determined in three different
frameworks, namely in the color dipole approach, in the approach of Baier et
al. and in the higher twist factorization formalism. This result enables one to
use a parametrization of the dipole cross section to estimate the values of the
gluon transport coefficient and of the higher twist matrix element, which is
relevant for nuclear broadening. A considerable energy dependence of these
quantities is found. In addition, numerical calculations are compared to data
for nuclear broadening of Drell-Yan dileptons, J/psi and Upsilon mesons. The
scale dependence of the strong coupling constant leads to measurable
differences between the higher twist approach and the other two formalisms.
