Whenever I see the amplitude for fermion scattering, it comes out dimensionless. However, for scalar scattering, the dimensions are 1/energy^2. For example, for 2 particles scattering into 2 particles in a [tex]\phi^3 [/tex] interaction, there is just one internal line, so the amplitude is proportional to 1/(-mandelstam+m^2), where "mandelstam" is of the order energy^2. Is this right?(adsbygoogle = window.adsbygoogle || []).push({});

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# Does probability have units

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