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Why do particle decay?

  1. Dec 2, 2015 #1
    For instancr like neutron decaying into proton electron and antineutrino. I read it in a book that says that according to Fermi, each of these particles are vibrations in different quantum fields and that each field exerted a tiny influence on the others. Because of quantum mechanics, we cant percieve the gradual transfer; we observe the neutrons and we either see it as a neutron, or we see that its decayed with some probability that can be calculated. Is this the reason? If is so, I dont really get what it means.
  2. jcsd
  3. Dec 2, 2015 #2
    What it means is that you should not picture a neutron as some how made up of proton electron and antineutrino. Rather neutron disappears and these appear. In other words neutron and the moving proton, electron and antineutrino. These two states are of the same quantum entity. These states are mutually exclusive. Either you see this or that. their individual occurence is truly governed by the law of probability. A neutron may decay within a particular time or may not decay at all.
  4. Dec 2, 2015 #3


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    Staff: Mentor

    All attempts to describe physical theories with words are problematic. You can shift the problems around a bit, but English will never give an accurate description of the physics.
    Also, we cannot answer "why" questions on a fundamental level. Physics can find theories that allow to calculate things like the lifetime from other observations, but "a neutron decays" is always a purely experimental result. If it would not decay, we would have to change the theories.
  5. Dec 2, 2015 #4
    Using words to describe physical phenomena is the same as model-building; a widely accepted method in science to develop hypotheses and theories.
    The problem is that we have no words or other constructs to describe physical phenomena that lie outside of our direct experience. It is in these cases that we must develop mathematical descriptions with their rigor so that everybody can understand. Why a neutron decays outside of the nucleus of an atom is big question with immediate application to describe matter in all of its states.
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