Elementary particle the proton should be uniform and the electron should scatter elastically. Low-energy electrons do scatter in this way, but, above a particular energy, the protons deflect some electrons through large angles. The recoiling electron has much less energy and a jet of particles is emitted. This inelastic scattering suggests that the charge in the proton is not uniform but split among smaller charged particles: quarks. In the Standard Model, vector (spin-1) bosons (gluons, photons, and the W and Z bosons) mediate forces, whereas the Higgs boson (spin-0) is responsible for the intrinsic mass of particles. Bosons differ from fermions in
W′ and Z′ bosons W′ and Z′ bosons In particle physics, W′ and Z′ bosons (or W-prime and Z-prime bosons) refer to hypothetical gauge bosons that arise from extensions of the electroweak symmetry of the Standard Model. They are named in analogy with the Standard Model W and Z bosons. W′ bosons often arise in models with an extra SU(2) gauge group. is spontaneously broken to the diagonal subgroup SU(2) which corresponds to the electroweak SU(2). More generally, we might have "n" copies of SU(2), which are then broken down to a diagonal SU(2). This gives rise to "n"−1 W′, W′ and Z′ bosons.