How to use relative energy / relative mass of particles (documentation question)

[cjnqt]

Hi,

How should the parameter relative energy deviation / relative mass deviation of the particle be used? For example, let's say we want to add a single proton and a single deuteron with the same energy. The deuteron has ~2 times the mass of the proton. What's the parameter for the deuteron's relative mass in permille – should it be 2000?

Proton

Particle(x, a, y, b, 0, 0)

Deuteron

Particle(x, a, y, b, 0, 2000) <-- Relative mass is 2 times the proton's mass?

[alexander-stolz]

The formula in this case is (2u/1u - 1) * 1000 permille, so the value is 1000.

Because both have the same energy, the energy deviation is (E/E - 1) * 1000 = (1 - 1) * 1000 = 0.

So:

proton:    Particle(x, a, y, b, 0, 0)
deuteron:  Particle(x, a, y, b, 0, 1000)

Or if you have a beam with some scattering you can use Beam() instead.

[cjnqt]

Great!