Nuclear transparency

Nuclear transparency is the ratio of cross-sections for exclusive processes from the nuclei to those of the nucleons.

If the nuclear cross-section is denoted as σ N and free nucleon cross-section as σ 0 then nuclear transparency can be defined as
T = σ N / A σ 0 , where σ N can be parameterized in terms of σ 0 as σ N = A α σ 0 .

Therefore, transparency can be expressed as T = A α − 1 .
Here nucleon cross-section can be thought of as hydrogen cross-section and nuclei cross-section can be as for other targets.