How are elementary particles born?

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Discussion Overview

The discussion revolves around the birth of elementary particles in the context of the early universe, specifically examining the relationship between particle mass and the sequence of their formation. Participants explore concepts related to the Friedman Equation, inflation, and reheating in the universe's timeline.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that if the Friedman Equation is used to determine the expected time for a particle's rest mass energy, it implies that more energetic particles were 'born' before lighter ones in a sequential order.
  • Another participant notes that all particles in the Standard Model acquire mass from the Higgs vacuum expectation value and emphasizes that prior to electroweak symmetry breaking, particles were effectively massless.
  • It is mentioned that after inflation, the universe underwent a reheating phase where particles with mass less than the reheating temperature could be produced.
  • A participant questions the concept of reheating after inflation, seeking clarification on whether inflation was so rapid that a subsequent period was necessary to achieve thermal equilibrium.
  • Further clarification is provided that inflation led to a cold universe, and the reheating phase involved the decay of the inflaton field into various forms of matter, resulting in a hot universe that subsequently cooled.
  • Another participant asks for specific details regarding the timing of the reheating phase and the types of matter produced from the inflaton field's decay.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and interpretation regarding the sequence of particle formation and the implications of reheating after inflation. There is no consensus on the exact timeline or mechanisms involved, indicating ongoing debate and exploration of these concepts.

Contextual Notes

Participants highlight the complexity of the early universe's conditions, including the effects of inflation and reheating, which are not fully resolved in the discussion. The relationship between particle mass and their formation sequence remains speculative.

Chaos' lil bro Order
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Hey,


If we use the Friedman Equation form to find time(excpected) for a given particle's Rest Mass energy as our input value, does it mean that the most energetic particles were 'born' first and the lighter particles 'born' later on in time in a linear, sequential order?

eg. T quark (174Gev)---->Z Boson(~90GeV)----->W Boson(~80GeV)---->B Quark(5GeV)------>Tau(~1777MeV)-----Proton(~938MeV)----->Electron(0.511MeV)------>etc...

Does the order of their Rest Mass energies mean they were 'born' in that order too?

Thanks, I'm very puzzled about this.
 
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A couple of things here. It's important to remember that everything in the Standard Model gets its mass from the Higgs vacuum expectation value (with the possible exception of right handed neutrinos). So in the early universe before the electroweak symmetry breaking everybody in the Standard Model looked a lot different i.e. they were all massless. Also, one of the roles of inflation is to dilute the density of topological relics like monopoles and so forth (this is necessary because we don't see monopoles). However, inflation diluted the density of everything else too! After inflation ended and the universe reheated, generally only those particles with mass less than the reheating temperature could be produced. In this sense, all the types of particles we see now were "born" at the time of reaheating.
 
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I don't understand you Physics Monkey.

You said after inflation, there was a 'reheating'? I thought the Universe's temperature has been steadily declining since then. Are you suggesting that inflation happened so fast that a period after it was needed to reach thermal equillibrium?

Please, give clearer arguments, I'm trying to follow you, but its difficult,
thanks.
 
Sorry if it was over your head, Order. It seemed based on your first post that you had a fair technical knowledge in this area.

The short story follows. The universe rapidly expanded during inflation, and the result was a very cold empty place. The matter and energy we now see came from a reheating phase when the "inflaton field" that was driving inflation decayed into other kinds of matter. The result was a hot universe that has since cooled.
 
interesting

Physics Monkey said:
The matter and energy we now see came from a reheating phase when the "inflaton field" that was driving inflation decayed into other kinds of matter. The result was a hot universe that has since cooled.


Ok, I'm following you now.

1) What time period did this 'reheating phase' take place in? Inflation ended at 10*-32 seconds, so from then to when did this phase take place?

2) How did the 'Infation field' decay into matter and what type of matter did it decay into?


Please feel free to speak technically, don't let me dumb your answers down.

Thanks again!:!)
 

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