Photo by Robert Morningstar

In other words, in any inertial reference frame and Cartesian components;

When,

there is no difference between bosons and fermions. In this case, a CPH carries gravitational force and behaves like a fermion. Therefore, there are color-charges, only.

When:

For particles like electrons or quarks;

Other bosons also occur. For example, reconsider pair production. Before pair production, there is a photon only. After pair production there is an electron, positron and a virtual photon (boson) that carries electromagnetic force. So, we can write:

Accordingly, a CPH with spin is called a graviton, so space is full of CPH. Increasing density of CPH in space causes their separation to decrease until they feel and absorb each other. Suppose two CPH are moving in the x-axis direction and absorb each other, such that their paths change without decreasing the magnitude of . According to relation (8), we are able to construct an operator , which rotates a CPH by an angle about the x-axis (toward z-axis or y-axis) in position space. Also, we can construct which rotates the CPH by about the x-axis in spin space. We would expect such an operator to take the form: