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Subatomic Particles

Elementary Mediator Particles

Bosons are particles defined to have spin of zero hbar, one h-bar, or two h-bar. The elementary mediator particles are bosons with spins of one h-bar. The force we are most familiar with is the electromagnetic force. The electromagnetic force is responsible for keeping electrons and nuclei together to form atoms. The electromagnetic force is mediated by photons, which are massless. The mediators of the strong force are called gluons, because they glue quarks together to form mesons and baryons. Like the quarks, the gluons carry the color property, and as a result there are eight different types of gluons.

The weak force is more uncommon. It is responsible for radioactive decays like nuclear beta decay. The mediators of the weak force are the electrically charged W-bosons (W±), and the electrically neutral Z-bosons (Z 0), both discovered in 1983. Some properties of the mediator particles are given in Table 2.

baryon quark content spin charge mass
p u u d 1/2 +1 e 938
n u d d 1/2 0 e 939
Λ u d s 1/2 0 e 1116
Σ+ u u s 1/2 1 e 1189
Σ0 u d s 1/2 0 e 1192
Σ- d d s 1/2 -1 e 1197
&NA;0 u s s 1/2 0 e 1315
&NA;- d s s 1/2 -1 e 1321
Λe+ u d c 1/2 1 e 2281
Δ++ u u u 3/2 2 e 1232
Δ+ u u d 3/2 1 e 1232
Δ0 u d d 3/2 0 e 1232
Δ- d d d 3/2 -1 e 1232
Σ*+ u u s 3/2 1 e 1383
Σ*0 u d s 3/2 0 e 1384
Σ*- d d s 3/2 -1 e 1387
&NA;*0 u s s 3/2 0 e 1532
&NA;*- d s s 3/2 -1 e 1535
Ω- s s s 3/2 -1 e 1672

Additional topics

Science EncyclopediaScience & Philosophy: Stomium to SwiftsSubatomic Particles - Neutrons, Quark Model, Elementary Mediator Particles, Baryons, Mesons, Current And Future Research - Discovery of particles, Subatomic particle classifications