Strong nuclear force

The strong nuclear force (also known simply as the strong force), is a fundamental force carried by gluons.

The strong force is a force that you do not encounter on the scale of our everyday life. The strong force acts on a tiny scale, even smaller than the size of an atom. For example, the strong force makes sure that the nucleus in the center of an atom is held together.

Because of the strong force, quarks are held together by gluons. Dependent on the color and the charge of these quarks, you can build protons, neutrons or pions.On your crafting grid, you can stick quarks together, when you use gluons as super glue. But you have to abide by the rules! You can only combine quarks in such a way that the sum of their colors is white. Strange, isn't it? The color combinations that lead to white are shown in the figure on the right.

If you combine three quarks, one quark has to be green, one quarks has to be blue and one quark has to be red. You can also combine two quarks to make the color white. The quarks should have the colors: red and anti-red (cyan), or blue and anti-blue (yellow), or green and anti-green (magenta). To get a color and an anti-color you have to take one quark and one anti-quark.

When you’ve chosen which colors you want to combine, you still have to decide on the charges of the quarks. Will you use (anti) upquarks or (anti) downquarks?

In case you stick two upquarks and one down quark together with gluons, you make a proton. If you stick one upquark and two down quarks together with gluons, you make a neutron.

In case you only use two quarks, the are four possibilities leading to three different particles called pions:


 * If you take an upquark and an anti-upquark, or a downquark and an anti-downquarks, you will get a pion0.
 * If you take an upquark and an anti-downquark you get a pion+.
 * If you take a downquark and an anti-upquark you get a pion-.