Nuclear transparency is the ratio of cross-sections for exclusive processes from the nuclei to those of the nucleons.
If a nuclear cross-section is denoted as and free nucleon cross-section as , then nuclear transparency can be defined as <br /> , where can be parameterized in terms of as .
Therefore, transparency can be expressed as .<br /> Here, nucleon cross-section can be thought of as a hydrogen cross-section, and nuclei cross-section can be as for other targets.