How does the electroweak interaction work


What is the weak interaction?

 

The weak interaction is an interaction that all building blocks participate in because they all have a weak charge.
The weak interaction takes place via three exchange particles, the so-called Weakonen or Vector bosons, instead of:

Z0
W.+
W.-

The Z is0 electrically neutral, while the W+ a charge of +1, the W- has a charge of -1.
All three exchange particles of the weak interaction are very heavy:

Mass of the W+ = Mass of the W- = 80 GeV / c2
Mass of the Z0 = 91 GeV / c2

Here W+ and W- the same masses since W- the antiparticle of W+ is.
These three exchange particles, which can also be counted among the elementary particles, are comparatively heavy. They are about 100m heavier than the proton with a mass of about 0.9 GeV / c2.
The fact that these exchange particles are so heavy is the reason that they only have an extremely short range (less than 10-15m) have! Therefore we do not notice anything of the weak interaction.

 


What happens with the weak interaction?

 

In the neutral weak interaction, that is, the one at which a Z0 involved, a quark, electron or neutrino sends a Z0-Boson off. This interaction is similar to the electromagnetic interaction, where a photon g would be emitted at this point. The neutral weak interaction only has an effect, in contrast to the electromagnetic interaction, on electrically neutral particles such as neutrinos.

In the charged weak interaction, so the one with a W+ or W-, care must be taken to maintain the charge. When a particle emits a charged W boson, this particle must change into another particle of the same charge. An example of this:
An electron sends a W- and changes to an electron neutrino:

This is due to the weak charge of the W bosons. The w- has a weak charge of -1, the W+ has a weak charge of +1. A change in the electrical charge is always coupled with a change in the weak charge. Accordingly, there is no weak or electromagnetic change in charge in the case of the neutral weak interaction.
The weak charge of the exchange particles also means that the exchange particles can interact with themselves.
W bosons decay after a very short time, whereby there are two possibilities for the end products:

1.) Leptons & neutrinos (e.g. e- + ne)
2.) Quark & ​​anti-quark (e.g. d + )

 


What are the 3 interactions of the weak interaction?

 

 

1.) Force:It is very short-range and is responsible, among other things, for the interaction between electrons or positrons and nucleons (e.g. ß-decay)
2.) Decay:

Radioactive ß-decay can be used as an example of a decay, which can be imagined as follows:

A neutron decays into a proton, emitting an electron and an electron neutrino. This happens under the influence of the weak interaction. How this works can be seen in the following figure:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As already said, all particles have a weak charge. In the case of ß-decay, a down quark breaks down into an up quark and a W.-. This W- has too great a mass, i.e. it is much heavier than the neutron and the proton combined. Therefore, it decays very quickly into an electron and an antineutrino. This antineutrino arises because otherwise the law of conservation of energy would not be fulfilled.
In the quark notation, the ß-decay can be written down as follows:

(u, d, d) ---> (u, u, d) + W-

W.- ---> e- +

3.) Production:

A muon (which corresponds to a heavy electron; details on the pages on the standard model) decays via the weak interaction, in the process two neutrinos (an electron antineutrino and a muon neutrino belonging to the muon, which is similar to the electron neutrino; details the pages for the standard model) and an electron is produced:

m--> nm + W-
W.- --> + e-

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