QCD sum rules for chiral partners in the open-charm meson sector are
presented at nonzero baryon net density or temperature. We focus on the
differences between pseudo-scalar and scalar as well as vector and axial-vector
D mesons and derive the corresponding Weinberg type sum rules. This allows for
the identification of such QCD condensates which drive the non-degeneracy of
chiral partners in lowest order of the strong coupling alpha_s and which
therefore may serve as "order parameters" for chiral restoration (or elements
thereof).Comment: 24 pages, 4 figure