  Based on the hard-scattering factorization which decomposes the diffractive
structure function into a pomeron flux and a pomeron structure function, we
study the single diffractive Lambda_c^+ production in polarized pp scattering:
p + p -> p + Lambda_c^+ + X, which will be observed at forthcoming RHIC
experiment. By analyzing the cross section and correlation of the spin
polarization between the initial proton and produced Lambda_c^+, we found that
the process is quite effective for testing both hard-scattering factorization
and models of the polarized gluon distribution in the proton.
