2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/108728With QCD sum rule evaluations, spectral changes of hadrons inside nuclear matter are considered, which shed light on QCD condensates and thus on the non-perturbative structure of the QCD ground state. For some light quark configurations, omega meson and nucleon, the relevance of four-quark condensates is compared; the D meson as a representative of heavy-light quark systems is also briefly discussed.Invited talk at the 44th International Winter Meeting on Nuclear Physics, Bormio, Italy, Jan 29 - Feb 5, 2006High Energy Physics - Phenomenologytext