The center-of-momentum frame is an inertial frame in which the total spatial momentum of a system vanishes. For a two-particle initial state, the momenta are equal and opposite and the total invariant energy is .
The centre-of-momentum energy is the total energy measured in the centre-of-momentum frame. For a scattering process with total four-momentum , it is the Lorentz-invariant quantity in the mostly-minus convention.
Articles by others on the same topic
The center-of-momentum (CM) frame, also known as the center-of-mass frame, is a specific reference frame used in physics, particularly in the study of collisions and particle interactions. In this frame, the total momentum of the system is zero. This means that the momenta of all the particles in the system balance out perfectly, resulting in a state where the center of mass is at rest.