Why do particles decay and what processes are involved?

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Discussion Overview

The discussion centers on the reasons behind particle decay, specifically focusing on particles like the tau muon, the processes involved in decay, and the fundamental forces that govern these interactions. It encompasses theoretical explanations, descriptions of decay mechanisms, and the classification of different types of decay processes.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants question why particles like the tau muon have short lifespans and why they decay into other particles.
  • One participant notes that physics can describe observations but cannot explain the "why" behind particle decay, suggesting that the decay of tau particles can be calculated based on other values.
  • Another participant describes the processes involved in particle decay, highlighting the role of the weak nuclear force and the interaction with W bosons in radioactive decay.
  • A detailed example of proton decay into a neutron is provided, illustrating the transformation of quarks and the conservation of charge during the process.
  • One participant challenges the assertion that the weak nuclear force is responsible for all types of radioactive decay, specifying that other decay types such as alpha decay and gamma decay are independent of the weak force.

Areas of Agreement / Disagreement

Participants express differing views on the completeness of the weak nuclear force's role in all decay processes, indicating a lack of consensus on the classification of decay types and the forces involved.

Contextual Notes

There are limitations in the discussion regarding the definitions of decay processes and the scope of forces considered, as well as unresolved aspects of the mechanisms behind particle decay.

Khadija Motala
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why is that particles such as the tau muon have a short lifespan and why is it that particles decay into other partcles? furthermore, what are the process that occur in particle decay?
 
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Physics cannot explain "why" - it can just describe the observations. Tau particles have a possible decay, and it is possible to calculate their lifetime (based on other values, like the muon lifetime), but that does not answer why they decay.
Concerning "how": Well, it can be described as interaction with the W boson.
 
Khadija Motala said:
what are the process that occur in particle decay?

In the standard model there are several fundamental forces of nature:Strong Nuclear Force
-Responsible for binding quarks together as well as protons and neutrons​
Weak Nuclear Force
-Responsible for all radioactive decay​
Electromagnetic Force
-Occurs between everything that has a charge.​
**Gravity has been debated over the years

Each of these forces has a corresponding particle known as a gauge boson that is responsible for carrying out those forces. The Strong Nuclear force is carried out by the Gluon, the Weak Nuclear force is carried out by the W and Z bosons (the W boson has positively charged and negatively charged variants,) and the Electromagnetic force is carried out by the Photon.

In the case of radioactive decay, all radioactive decay occurs as a result of the weak nuclear force. The weak nuclear force is important as it is the only known force that has the potential to change the flavor (characteristics) of a quark. Take, for example, the decay of a proton into a neutron.

A proton is composed of two up quarks and a down quark and a neutron is composed of two down quarks and an up quark.
p → n + w+
The w+ boson then decays into a positron e+ and an electron anti neutrino ̅νe.
So: p → n + e+ + ̅νe.
The positron and antineutrino conserve charge. As a result of the interaction with the w+ boson, one of the up quarks changes into a down quark.

http://en.wikipedia.org/wiki/Standard_Model
 
Last edited:
AbsoluteZer0 said:
Weak Nuclear Force
-Responsible for all radioactive decay​
Not all, just beta decays.

Alpha decays, gamma "decays", proton emission, neutron emission, cluster decays and fission are independent of the weak force.
 

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