User:John R. Brews/Coriolis force

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Quarks

Quarks are a type of particle with spin 1/2 that are subject to strong, weak and electromagnetic forces. The known quarks are listed in the table below. The kinds of quark (u, d, c, s, t, d) are referred to as the flavor index of the quark, and besides a flavor index, each quark has a color index, which may be any of three colors: red, green and blue (r, g, b). In a stretched analogy to light, a combination of three quarks with all three colors is referred to as "white" or "colorless" and exhibits no external evidence of a color index. Their antiparticles also are quarks, but carry anti-colors: anti-red, anti-green, anti-blue. A combination of quark and anti-quark with a color and its anti-color is "white" or "colorless".

Unlike a particle's electric charge, which can be any multiple of the elementary charge e, a quark can carry only one unit of color. The elementary unit of color has not been measured, a result of failure to observe an isolated quark.

Quark flavor properties[1][2]
Name Symbol Family/Generation B YW Q(e) IS3 C S T B′ Mass (MeV) Antiparticle Antiparticle symbol
Up u 1 +1/3 +1/3 +2/3 +1/2 0 0 0 0 2.34 ± 0.19 [3] Antiup ū
Down d 1 +1/3 +1/3 −1/3 −1/2 0 0 0 0 4.78 ± 0.11 [3] Antidown
Strange s 2 +1/3 −2/3 −1/3 0 0 −1 0 0 100.2 ± 2.4[3] Antistrange
Charm c 2 +1/3 +4/3 +2/3 0 +1 0 0 0 1.294 ± 0.004 × 103 [3] Anticharm
Bottom b 3 +1/3 -2/3 −1/3 0 0 0 0 −1 4.19 (+0.18) (−0.06) × 103 [3] Antibottom
Top t 3 +1/3 +4/3 +2/3 0 0 0 +1 0 172.9 ±0.6 ±0.9 × 103 [3] Antitop
B = baryon number,YW = weak hypercharge, Q = electric charge, IS3 = strong isospin, C = charm, S = strangeness, T = topness, B′ = bottomness.
* Notation such as ±xxx denotes measurement uncertainty. In the case of the top quark, the first uncertainty is statistical in nature, and the second is systematic.

The quarks carry fractional electric charge. However, no quark has been observed in isolation, so a "free" fractional electric charge has not been seen.

The quark structure of some strongly interacting sub-atomic particles (some hadrons) is shown in the following tables.[4]

Some baryons
Name Symbol Quark structure Electric charge Spin
Proton +1 1/2
Antiproton −1 1/2
Neutron 0 1/2
Lambda 0 1/2
Omega −1 3/2

Some mesons
Name Symbol Quark structure Electric charge Spin
Pion +1 0
Kaon −1 0
Rho +1 1
D-plus +1 0
Eta-c 0 0

All baryons must have all three colors present, r, g, and b, and so are colorless, and exhibit no external evidence of the strong color interaction. Likewise, regardless of the flavor combinations in a meson, the colors of the quark-antiquark cancel, so the meson also is colorless to the outside world.[5] The role of the color force is thus simply to hold the quark combinations together, which is accomplished by exchange of gluons among the constituent quarks.

The quarks that may engage one another in reactions are determined by the Cabbibo-Kobayashi-Maskawa matrix:Morii

The quarks can be arranged to exhibit right- and left-handedness, subscripts L and R, to resemble the leptons. The right-handed quarks do not couple to the weak interaction, and are labeled with subscript R. The left-handed quarks corresponding to these right-handed quarks are mixtures of quarks. Thus, the up and down quarks are assembled as:

The other generations are arranged similarly:

Right- and left-handed quarks
Symbol Electric charge, Q Weak isospin, (IW, IW3) Weak hypercharge, (YW)
uL, cL, tL +2/3 (1/2, +1/2) +1/3
dL, sL, bL −1/3 (1/2, −1/2) +1/3
uR, cR, tR +2/3 0 +4/3
dR, sR, bR −1/3 0 −2/3
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