Sihver Formula

Of the four parameterizations, the Sihver formula has the simplest form:

$$\sigma_{R} = \pi r^{2}_{0}[A^{1/3}_{p} + A^{1/3}_{t} - b_{0} [A^{-1/3}_{p} + A^{-1/3}_{t}] ]^{2}$$ (16.1)

where A$_{p}$ and A$_{t}$ are the mass numbers of the projectile and target nuclei, and

$$\begin{eqnarray*} b_{0}=1.581-0.876(A^{-1/3}_{p} + A^{-1/3}_{t}) , \end{eqnarray*}$$

$$\begin{eqnarray*} r_{0}=1.36fm. \end{eqnarray*}$$

It consists of a nuclear geometrical term $(A^{1/3}_p + A^{1/3}_t)$ and an overlap or transparency parameter ($b_0$) for nucleons in the nucleus. The cross section is independent of energy and can be used for incident energies greater than 100 MeV/nucleon.