Strong force, quarks, hadrons.

[PeterPumpkin]

I'm reading The Lightness of Being by Frank Wilczek.

The strong force falls off rapidly with distance. And yet when we attempt to separate two quarks the force increases enormously.

I assumed the strong force acted between hadrons (= groups of quarks) and between quarks but this assumption seems inconsistent with the change of force with distance.

EG Does this mean that the strong force acts only between hadrons ie groups of quarks?

 

[Bill_K]

There's two separate issues here, the interaction between quarks and the interaction between hadrons. The interaction between quarks is called the 'color force' and only acts between particles that have color, namely quarks and gluons. It results from virtual exchange of gluons. This is the force that gets stronger with increasing distance.

The interaction between hadrons is called the strong force or nuclear force. It results from virtual exchange of other hadrons. Its range is dictated by the mass of the lightest hadron, the pion, at 135 MeV, equivalent to about 1.4 fermis.

 

[PeterPumpkin]

Thanks. That would seem to imply there really are 5 fundamental forces in nature: Gravity, em, weak, strong force and the "colour force".

 

[Drakkith]

Thanks. That would seem to imply there really are 5 fundamental forces in nature: Gravity, em, weak, strong force and the "colour force".

The strong force that acts between nucleons (or hadrons) is similar to the Van Der Waals force between atoms in molecules. Both are a result of an actual force and are not real forces in themselves. (Electromagnetic force for VDW, color for strong force.)