Physics:Nuclear transparency

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 ${\sigma }_N$ and free nucleon cross-section as ${\sigma }_0$, then nuclear transparency can be defined as
$T={\sigma }_N/A{\sigma }_0$, where ${\sigma }_N$ can be parameterized in terms of ${\sigma }_0$ as ${\sigma }_N=A^{\alpha }{\sigma }_0$.

Therefore, transparency can be expressed as $T=A^{\alpha -1}$.
Here, nucleon cross-section can be thought of as a hydrogen cross-section, and nuclei cross-section can be as for other targets.