Do Matter and Antimatter React to Each Other in the Same Way?

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    Antimatter Properties
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Discussion Overview

The discussion centers around the interactions between matter and antimatter, specifically questioning whether they react to fundamental forces in the same way and exploring the proportions of antimatter compared to matter in the universe. The conversation touches on theoretical implications, experimental observations, and the concept of CP violation.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants inquire about the proportions of antimatter to matter and express uncertainty about the current understanding of this ratio.
  • It is noted that, in the observable universe, matter vastly outnumbers antimatter, but this is not attributed to a large asymmetry in the early universe.
  • Some participants explain that gravity, electromagnetism, and the strong force affect matter and antimatter similarly, while the weak force exhibits CP violation.
  • There is a suggestion that the observed CP violation in weak interactions is insufficient to fully explain the matter-antimatter asymmetry, indicating the possibility of unknown sources of CP violation.
  • One participant references the PAMELA experiment, which aimed to measure cosmic ray antimatter but reportedly did not find significant results.
  • Another participant discusses specific experimental observations related to B mesons and their decay times, illustrating differences in behavior between matter and antimatter under certain conditions.

Areas of Agreement / Disagreement

Participants express both agreement and disagreement on various points, particularly regarding the nature of interactions between matter and antimatter and the implications of CP violation. The discussion remains unresolved on several aspects, particularly concerning the exact proportions of antimatter and the reasons for the observed asymmetry.

Contextual Notes

Limitations include the dependence on current experimental results and theoretical models, as well as the unresolved nature of CP violation and its implications for matter-antimatter interactions.

hsdrop
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do we know what the proportions of antimatter is compared to matter ?? like does gravity electromagnetism the strong and weak forces exc...as well as other thing like does it react to it self the same way matter does to it self??
 
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In the observable Universe, matter vastly outnumbers antimatter ... but, within experiments, antimatter is always accompanied by an equal amount of matter.
Antimatter has the same interactions as regular matter, including the self-interaction ... however, there is this thing called the CP violation which may explain the dominance of matter over antimatter.

Thus: if you search using "CP violation" among your terms, you will find lots of information on the subects you are asking about.
 
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Simon Bridge said:
In the observable Universe, matter vastly outnumbers antimatter
It is worth mentioning that this is not due to a large asymmetry between matter and antimatter. In the early universe, there was almost equal amounts. What happened was that there was a slight excess of matter and when matter and antimatter annihilated away, this small excess was left as it had nothing to annihilate with. This small excess is all the matter we see today.

As far as we are aware, gravity, electromagnetism, and the strong force affect matter and antimatter in the same way. The weak force displays CP violation. It is worth noticing that the observed CP violation in the weak force is not sufficient to explain why there was slightly more matter in the early universe. This indicates that there should exist another source of CP violation that we do not know about (yet!). This is an open field of research.
 
Go to this link and watch this video. It will make you understand more.
 
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hsdrop said:
do we know what the proportions of antimatter is compared to matter ??
In general no, we don't. We only know that we love in a matter-dominated (dominated in the sense of matter-antimatter) world. Experiments, like PAMELA, aim in measuring such an asymmetry in the Universe. PAMELA aimed to do that by measuring the flux of antimatter in cosmic rays which would come from the residual antimatter from the Big Bang. As far as I know PAMELA did not observe any kind of primary cosmic ray antiproton result (https://arxiv.org/pdf/1801.10310.pdf Fig.13 and paragraph under it).

hsdrop said:
like does it react to it self the same way matter does to it self??
Yes most of the times, except for if there is CP-violation in the game. In the CP violation scenario, matter and antimatter interactions differ.
One nice example is shown in this beautiful plot from Babar:
BaBar_B0B0bar_JPsiKs_Asymmetry_ICHEP2008_400px.png

The idea is that you have the production of B_{\text{tag}}^0\bar{B}^0 mesons... and you measure the B_{\text{tag}}^0 meson's evolution over time (compared to the \bar{B}^0)..The nice thing with the neutral B mesons is that there is a possible transition B\rightarrow \bar{B} \rightarrow B^0 \rightarrow ... etc. Now you can measure how much time it takes the B_\text{tag}^0 to decay (and also see if it decays as a B or \bar{B}) (t or t' respectively) and compare it to the time of decay of \bar{B}^0 (\bar{t}).
Then you have this variable \Delta t = \bar{t} - t (blue markers) or =\bar{t}-t' (red-markers) (so if the tag decays second, the time difference is negative).
The fact that the B^0_\text{tag} and \bar{B}_\text{tag}^0 have so different \Delta t (their asymmetry is shown in the bottom panel) is obviously due to different behavior between matter B^0_\text{tag} and antimatter \bar{B}^0_\text{tag}

Orodruin said:
strong force affect matter and antimatter in the same way.
One day... Until that one day, when axions are observed... :nb)
 

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