  Double parton scattering is sensitive to correlations between the two partons
in the hadron, including correlations in flavor, spin, color, momentum
fractions and transverse separation. We obtain a first estimate of the size of
these correlations by calculating the corresponding double parton distribution
functions in a bag model of the proton. We find significant correlations
between momentum fractions, spin and flavor, but negligible correlations with
transverse separation. The model estimates of the relative importance of these
correlations will help experimental studies disentangle them.
