The four fundamental forces of nature are, in order of strength: strong nuclear, electromagnetic, weak nuclear, and gravitational. Quarks interact via the strong force, but leptons do not. Both quark ...The four fundamental forces of nature are, in order of strength: strong nuclear, electromagnetic, weak nuclear, and gravitational. Quarks interact via the strong force, but leptons do not. Both quark and leptons interact via the electromagnetic, weak, and gravitational forces. Elementary particles are classified into fermions and boson. Fermions have half-integral spin and obey the exclusion principle. Bosons have integral spin and do not obey this principle.
This is illustrated in the left panel in Figure \PageIndex6:. In Feynman’s view, this process is equivalent to the scattering of an A particle backward in time by a B particle, the scatt...This is illustrated in the left panel in Figure \PageIndex6:. In Feynman’s view, this process is equivalent to the scattering of an A particle backward in time by a B particle, the scattering of an ˉA backward in time by a B particle, the creation of an ¯AA pair moving backward in time by a ˉB particle (an antiB), and the emission of a B particle by an A particle moving forward in time.
