What is strong force in physics

There are only four forces

Everyone feels the gravitational pull of the earth - without it we would float like astronauts in space. That force is gravity. Everyone is also familiar with magnetic and electrical forces. Furthermore, one experiences many other forces in everyday life, such as muscle strength, frictional force, the force of a spiral spring or the force exerted by a surface (e.g. a table). When researching atoms and nuclei, physics has also come across new force effects that hold the atomic nucleus together or cause certain particle transformations.

Similar to the investigation of the structure of matter, particle physics tried to clarify which of these forces are "fundamental", i.e. to which force effects all others can be traced back. This investigation has shown that the enormous number of different force effects that we experience in everyday life or in physical experiments, only 4 basic forces underlie!

The most well-known basic forces are certainly the Gravity and the Electromagnetism. In addition to these everyday interactions, two other interactions play a role at small distances, as are relevant in particle physics, namely the so-called. weakness and the Strength Force. While the strong force is responsible for the fact that the quarks are bound to protons and neutrons (and also that the protons and neutrons of an atomic nucleus are bound), the weak interaction in our everyday world only manifests itself in special forms of radioactivity.

These forces are summarized in the following table:

The strong force rightly bears its name: Its effect is so strong that the quarks bound to hadrons cannot appear as free particles. This effect is called inclusion (confinemment). The investigation of QCD (quantum chromodynamics, QCD for short) is a research focus of the Wuppertal working group.

With the exception of gravitation, all these forces are described by the so-called standard model of particle physics. It includes the theory of the strong interaction (QCD) as well as the electroweak theory according to Glashow, Salam and Weinberg (GSW for short). All these forces are described by so-called gauge theories. From this it follows, among other things, that the force effect is explained by the exchange of so-called calibration bosons. These exchange particles are also given in the table.

back