WOLFRAM|DEMONSTRATIONS PROJECT

Feynman Amplitude and Scattering Cross-Section for a Toy Theory

​
exchange particle mass 
choose plot
amplitude
differential cross section
Amplitude and differential cross sections for two-body scattering
(A+AA+A)
are calculated using a second-order Feynman diagram of a toy theory (no spin, no charge, no polarization, no color) in the center of mass system. The graphs show the Feynman amplitude ℳ and the differential cross section dσ/dΩ as functions of the scattering angle θ, in radians. You can vary the mass
m
of the exchanged virtual particle and see how the curves behave.
The general relation between differential cross section and Feynman amplitude is:
​​
2
σ
Ω
=
2
ℏ
64
2
π
s
p
f
p
i
ℳ
fi
.