Add energy loss process

Focus on muons and hadrons. Electrons can be handled separately later.

mentioned in issue #108 (closed)

added Critical label

mentioned in issue #126 (closed)

assigned to @rulrich

created merge request !83 (merged) to address this issue

mentioned in merge request !83 (merged)

As it turns out, the Bethe formula with density (Sternheimer) correction requires 8 additional material properties... We need a smart way to add this to the Environment in a general way (without normal user interference).

// all these are material constants and have to come through Environment
// right now: values for nitrogen_D
// 7 nitrogen_gas 82.0 0.49976 D E 0.0011653 0.0 1.7378 4.1323 0.15349 3.2125 10.54
auto Ieff = 82.0_eV;
auto ZoverA = 0.49976_mol/1_g;
const double x0 = 1.7378;
const double x1 = 4.1323;
const double Cbar = 10.54;
const double delta0 = 0.0;
const double aa = 0.15349;
const double sk = 3.2125;
// end of material constants

Can you provide a reference? I want to know the origin of these numbers.

Never mind, I found the paragraph in the PDG.

mentioned in issue #52 (closed)

closed via merge request !83 (merged)

mentioned in commit dd2e4867