# Lars Eighner's Homepage

## LarsWiki

### Quarks

Murray Gell-Mann

#### Introduction

According to the Standard Model, quarks are elementary particles. Quarks compose hadrons which include baryons the most familiar of which are the atomic particles the neutron and the proton.

##### Flavors of Quarks

Quarks come in six flavors (types). These are up, down, strange, charm, top, and bottom, denoted:

Quarks {$$\begin{array}{l|l|l} \\{\Large\bf u } \text{ up } &{\Large\bf s } \text{ strange } &{\Large\bf t } \text{ top }\\ {\Large\bf d } \text{ down } &{\Large\bf c } \text{ charm } &{\Large\bf b } \text{ bottom }\end{array}$$} which all have antiparticles denoted with an overscore:

Antiquarks {$$\begin{array}{c|c|c} \\\overline{\Large\bf u } &\overline{\Large\bf s } &\overline{\Large\bf t } \\ \overline{\Large\bf d } &\overline{\Large\bf c } &\overline{\Large\bf b } \end{array}$$}

Up, strange, and top quarks are called collectively top-type quarks. Down, charm, and bottom quarks are bottom-type.

Up and down quarks are called first generation, strange and charm quarks are called second generation, and top and bottom quarks are called third generation. The distinctions of generation are also found in leptons. Generally, particles of the higher generation are more massive and less stable than the lower generation.

##### Properties of Quarks
###### Charge

Quarks have fractional electric charges. Up-type quarks have a charge of +2/3. Down-type quarks have a charge of -1/3. The signs of the charges are reversed in antiquarks. As a result, the combination of an up-type quark and two down-type quarks results in a net charge of 0, as in a neutron, while a combination of two up-type quarks and down-type quark results in a net charge of +1, as in a proton.

###### Spin

Quarks have spin which can have values of +½ or -½ also sometimes represented by ↑ and ↓. Values of spin are also sometimes called up and down, although this is best avoided to prevent confusion with the flavors of quarks.

###### Color

Quarks have color, usually designate R (red), G (green), and B (Blue). These have nothing to do with the colors of visible light, but there is an analogy in the way colors add. Each of the colors has an anticolor (antired, antigreen, and antired). And as might be expected, antiquarks have anticolors.

Sources:

Recommended:

Category:

### December 22, 2018

• HomePage
• WikiSandbox

Lars

Contact by Snail!

Lars Eighner
APT 1191
8800 N IH 35
AUSTIN TX 78753
USA

Help