Page "Color confinement" Paragraph 3

The reasons for quark confinement are somewhat complicated ; no analytic proof exists that quantum chromodynamics should be confining.

The current theory is that confinement is due to the force-carrying gluons having color charge.

As any two electrically-charged particles separate, the electric fields between them diminish quickly, allowing ( for example ) electrons to become unbound from atomic nuclei.

However, as two quarks separate, the gluon fields form narrow tubes ( or strings ) of color charge, which tend to bring the quarks together as though they were some kind of rubber band.

This is quite different in behavior from electrical charge.

Because of this behavior, the color force experienced by the quarks in the direction to hold them together, remains constant, regardless of their distance from each other, at around 10, 000 Newtons.