Talk:Baryogenesis

Wiki Education Foundation-supported course assignment

This article was the subject of a Wiki Education Foundation-supported course assignment, between 17 January 2021 and 8 May 2021. Further details are available on the course page. Student editor(s): Zwigmaster.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 15:21, 16 January 2022 (UTC)

Baryogenesis in Ultra-Curved Spacetime of early Closed Cosmos

Do the equations underlying the analysis of Baryogenesis implicitly assume a FLAT spacetime? What if the Cosmos is CLOSED, so that the early universe was a highly curved hyper-sphere ("Sphereland" in 2D). Such a highly curved spacetime fabric would be ASYMMETRIC, w/ pronounced differences between the "inside edge" of the hypersphere, and its "outside" (especially if, as seems reasonable, spacetime has some "thickness" in the extra hyperspace dimension). Could such an asymmetry help explain the asymmetry of matter vs. anti-matter ?? —Preceding unsigned comment added by 66.235.26.150 (talk) 08:22, 7 May 2010 (UTC)

Baryon number conservation

Technically, this translates as the commutator of the baryon number quantum operator with the Standard Model hamiltonian operator is zero: [B,H] = BH - HB = 0.

It's not, you know. Instantons change the baryon number. Phys 14:08, 18 Jan 2005 (UTC)

Definitions of matter and antimatter

What if are definitions of matter and anti-matter are wrong?

Let us redefine matter and anti-matter based on charge, matter is positively charged and anti-matter is negatively charged. We then get the following:

Matter

Positron

Up quark

Anti-matter

Electron

Down quark

A proton would now consist of 2 parts matter and 1 part anti-matter.

A hydrogen atom would now consist of 2 parts matter and 2 parts anti-matter.

As you can see the asymmetry has vanished, matter and anti-matter are distributed equally throughout the universe.

—The preceding unsigned comment was added by 82.42.190.64 (talk • contribs) .

• That doesn't make any sense. The down-quark clearly isn't the antiparticle of the up-quark. Antiparticles aren't some arbitrary definition, they are an immediate consequence of Quantum Field Theory, which is the most successful description of nature that we have. 142.3.164.195 22:07, 12 May 2006 (UTC)

I'm not implying that the down-quark is the anti-particle of the up-quark. I was saying what if all positively charged particles are really matter and all negatively charged particles are anti-matter, then positrons, up-quarks and anti-down-quarks would be considered as matter, while electrons, anti-up-quarks and down-quarks would be considered as anti-matter.GoldenBoar 03:01, 23 August 2006 (UTC)

In that case protons would not be stable and would self-annihilate, due to the negatively-charged down quark and positively-charged up quarks. Obviously that doesn't happen. Not to be rude, but you might learn something by reading a standard reference textbook on particle physics (e.g. Griffiths, Introduction to Elementary Particles, or one of the many others). —The preceding unsigned comment was added by 142.104.60.203 (talk) 00:33, 20 March 2007 (UTC).

I think he's just proposing a name change, declaring by fiat that the positively charged member of a particle/antiparticle pair be the one considered "matter". The problem, other than trying to overturn the existing definition, is that you still have the asymmetry (we see lots of electrons but no positrons, whichever one is considered "matter" or "antimatter"). --Christopher Thomas 00:43, 20 March 2007 (UTC)

OK, certainly, you could make all the name changes you like, but you wouldn't change the physical baryon asymmetry of the universe (or whatever you change that name to) -- it's a meaasurable (and measured), not a gauge-dependent, quantity. I propose not announcing on the arxiv that a few jerks on Wikipedia have changed the definition of matter and antimatter. :) 142.104.60.203 07:18, 25 August 2007 (UTC)

Effectively, what he's really done is just proposed a random, irrelevant, what-if situation. What if matter didn't exist at all? Who cares? 03:16, 4 November 2007 (UTC) —Preceding unsigned comment added by 24.208.253.57 (talk)

Baryogenesis/CP-violation "Disputed" New Discovery

I've removed the following recently-added text from the article, as it looks like it was based on an April Fools joke:

Scientists working at a large physics lab in the US have recently tried to explain why such an imbalance of antimatter and matter exists, with the experimental proof of the "B-Sub s meson". They have found that this subatomic particle "switches" between antimatter and matter at a rate of 17 trillion times per second. Although this announcement has gone largely unnoticed by the public, top physicists around the world are hypothesizing that this amazingly fast change is responsible for hiding unstable antimatter reactions "inside quantum foam". The proof of this particle confirms the fundamental particle theory held by the majority of scientists as of now.

On the off chance the press release (from March 23rd) wasn't intended as a joke, this addition is still very questionable. First, the LHC (at CERN, in Europe, not the US) won't be online until 2007 at the earliest. The press release I found mentiones a "DZero" detector, of which the closest match I can find is the D0_experiment using the Tevatron (at Fermilab). Second, this rather drastic claim (of a particle that oscillates between being matter and being antimatter) appears to be based on a single paper submitted to a "Letters" journal (these tend to have less stringent review, as they're intended for results that must be speedily released, though this does vary from journal to journal). --Christopher Thomas 06:35, 4 April 2006 (UTC)

Yes, it's confusing. They are certainly referring to the D0 experiment at Fermilab. Phys. Rev. Lett. is far and away the most prestigious journal in physics, though. I'll leave a message for SCZenz to come and have a look at this. I don't really know what the oscillation means, since mesons are quark-antiquark color singlets, but it probably has something to do with phases and the CKM matrix (just like the neutrino oscillations have to do with phases and the MNS matrix). It doesn't seem funny enough to be April Fool's, though. –Joke 15:38, 5 April 2006 (UTC)

The oscillation of the $B_{s}^{0}$ is real, and experiemnts like BaBar, CDF, and D0 do investigate such things. The bit about the LHC was an error; it's not running yet. However, the discovery is real, it was done by D0 (see this Fermilab press release). The bit about quantum foam is jargon I've never heard, and I suspect was made up; however, B meson oscillations do shed light on the asymmetries between matter and antimatter, which we believe may explain why there's no antimatter around. However, this latest result appears to be consistent with the Standard Model of particle physics, which doesn't predict enough assymetry to fully explain the lack of antimatter in the universe. -- SCZenz 21:32, 5 April 2006 (UTC)

Quantum foam is a common term. The article is not an April Fools Joke. Rotiro 07:12, 14 April 2006 (UTC)

Sorry, let me be clearer. The phrase "inside quantum foam" is jargon I've never heard, and was imprecise enough in that context that it didn't seem to mean anything. And yes, it's real, which is precisely what I concluded. -- SCZenz 14:41, 14 April 2006 (UTC)

If you feel that any of this information would be useful to add to the article, please do, as you're in a better position to assess it than I am. --Christopher Thomas 21:52, 5 April 2006 (UTC)

Heh, I didn't look at that—but now I have. I think the ideas are already covered in CP-violation#CP violation and the existence of the universe, which is a more proper place for this information—anyway, I don't think the new discovery sheds might light on what's already there. -- SCZenz 22:38, 5 April 2006 (UTC)

Sorry for the misinformation a while back, here is the Press releasethat I have come across...it is not as enlightening as your one below, but it helps in clearing a few points, such as the fact that it points to a major US lab (Fermilab, not LHC) that has made the discovery. --—The preceding unsigned comment was added by Regodude (talk • contribs) on 01:09, 12 April 2006.

Yep, that's the information I found, pretty much, but written for a different audience. This particular discovery doesn't shed much light on baryogenesis because it just confirms the CP violation predictions of the Standard Model—which are too small to fully explain baryogenesis. But anyway, yeah, you were on the right track. :) -- SCZenz 18:08, 12 April 2006 (UTC)

SCZenz is entirely correct, as are the first two sentences of the text in question. The last two sentences of the text in question are, however, out of left field. B_s oscillations have certainly now been observed paper 1 paper 2(by the two different experiments at the Tevatron, CDF and D0) and are entirely in accordance with the predictions of the Standard Model. They, and the Standard Model, do _not_ explain baryogenesis, and the theoretical physics community does not, by any stretch of the imagination, seriously maintain any connection between this result and "quantum foam." 142.104.60.203 03:34, 10 March 2007 (UTC)

Re the philosophical discussion

I don't understand the essential argument. Is the author positing that life is not possible in an antimatter segment of the universe? Symmetrical considerations seem to imply that it is. In any event, this section seems nebulous and its message is vague.

Please review

"The exact experimental value involves measuring the concentration of chemical elements in the universe not originating from stellar synthesis."

The above sentence needs to be repaired. Michael H 34 17:56, 16 August 2007 (UTC) Michael H 34

I agree. I don't have any scientific background, but I don't see why it matters whether they originated from stellar synthesis or not. Stellar synthesis don't make matter, it simply rearranges it into the phenomenon we now as a star. If you're studying origins of matter, the matter is matter. I don't see why it's significant what other matter is nearby. —Preceding unsigned comment added by 24.208.253.57 (talk) 03:38, 4 November 2007 (UTC)

Word unclear (to me)

In the phrase "where the conservation of baryon number is broken perturbatively" it isn't clear to me what perturbatively means. Is it possible to clarify that? 77.100.103.108 (talk) 04:49, 8 October 2008 (UTC)

It means that one uses perturbation theory to dig out the results. Figuratively, you write the phenomenon in a very simplistic model and then you assume that the "interesting" part behaves as a small effect displacing the simple model, and see what comes out of such simple + perturbation model. —Preceding unsigned comment added by 193.126.230.50 (talk) 10:39, 30 November 2010 (UTC)

Cubic Kelvin

Does "cubic kelvin" actually mean anything? How do you cube such a unit?

Soronel (talk) 06:09, 4 September 2009 (UTC)

Yeah, that was just wrong -- fixed. Rafaellang (talk) 12:40, 21 March 2013 (UTC)

Nothing = 0?

In the Background section of the article, one of the "points of view" given to support the idea that the universe was originally perfectly symmetric is: "if the universe encompasses everything (time, space, and matter), nothing exists outside of it and therefore nothing existed before it, leading to a total baryonic number of 0." I tagged this as needing a citation, but Headbomb removed that tag [1], saying that "nothing = 0" is obvious. My reason for adding the tag is that I question whether a statement about what exists "outside" or "before" the universe is a valid scientific claim. It seems intuitive, in some sense, that "nothing" should imply a baryonic number of 0, I suppose, but is this an actual, meaningful idea that we can ascribe to a reliable scientific source, or is this just a hand-wavy pseudo-explanation invented by some Wikipedia editor to appeal to intuition? (I don't have any knowledge about particle physics or cosmology, so I don't know the answer to this question—that's why I asked for a citation.) —Bkell (talk) 06:22, 3 December 2010 (UTC)

It's pretty much the explanation any particle physicist would give you for this. If you have n baryons and m antibaryons, you have a baryon number of n − m. If you have nothing, then you have no baryon/antibaryons (n = 0, m = 0), thus n − m = 0 . It would be pretty hard to find this specific claim in books, simply for the reason that no one probably ever bothered to write this down. Not saying it's impossible to find one, but it's not something that warrants a "citation needed" tag. Headbomb {talk / contribs / physics / books} 06:58, 3 December 2010 (UTC)

Okay, sure, if a system has no baryons and no antibaryons then the system has a baryon number of 0, I agree. But what's the basis for the belief that "nothing" existed before the Big Bang (or before the Planck epoch or whatever)? Is it even meaningful to discuss what existed before then? Is there even a "before then" to discuss? The article presents this "nothing before the Big Bang" idea as a reason for the belief that the universe started out in symmetry and then something happened to break it. If this "nothing before the Big Bang" idea really is the reason that (most? many? some?) scientists believe that the universe began in symmetry, then we should be able to find a reliable source that gives this idea as a reason for this belief and hopefully clarifies what the idea means. Otherwise, claiming it as justification seems to me to be unsupported speculation or hand-waving, especially if "before the Big Bang" and "outside the Universe" are physically meaningless phrases. —Bkell (talk) 09:06, 3 December 2010 (UTC)

Hence why the whole thing is prefaced with "If the universe emcompasses everything". The idea being conveyed here is that if you start with nothing, then you have no net baryon number. Wheter it's even meaningful to even speak of a start is best left to philosophy (see Newton's Flaming Laser Sword). Headbomb {talk / contribs / physics / books} 09:27, 3 December 2010 (UTC)

Well, the chain of reasoning "There was nothing before the Big Bang, therefore the baryon number of the Universe was 0, and therefore the baryon number of the Universe just after the Big Bang must have been 0 too" seems either very naive or very profound. It certainly does not seem to be a self-evident postulate to me, because it's based on so many premises that appear to be meaningless. Look, I'm not arguing either for or against that reasoning—I just want a citation to a reliable source, so that I can confirm that it isn't something completely naive that some Wikipedia editor just made up. —Bkell (talk) 18:14, 3 December 2010 (UTC)

The claim is not that there was nothing before the big bang, therefore the baryon number is zero, but rather if there were nothing before the big bang, then the initial baryon number is zero per definition of what nothing and zero means. This is as deep/naive as saying an empty bag contains zero apples (or oranges, if you prefer oranges). Headbomb {talk / contribs / physics / books} 16:08, 15 December 2010 (UTC)

Look, I'm not disputing that "nothing" means "baryon number is zero"—what I am saying is that it is not at all clear to me that the "nothingness" before the Big Bang (which itself is a statement that seems to have no meaning) should have any relation at all to the situation after the Big Bang. Why should it be the case that the Big Bang preserved baryon number? As I understand it, the paragraph under discussion here says that there are (at least) two possibilities: (a) the Big Bang itself created more matter than antimatter, or (b) the Big Bang preserved the baryon number of "nothingness" and something else later, baryogenesis, caused matter to predominate. The whole point of the paragraph is that possibility (b) is "preferred" because there was "nothing" before the Big Bang. But that doesn't explain anything—isn't possibility (a) also fine if there was "nothing" before the Big Bang? What possible reason do we have to believe that the Big Bang preserved baryon number? Assuming that the baryon number of the Universe before the Big Bang was zero (again, I can't see how this is a meaningful statement, but whatever), why is it more likely that some mysterious "baryogenesis" process was responsible for the current predominance of matter over antimatter, rather than the Big Bang itself? Any argument that the Big Bang should have preserved baryon number (so that the baryon number of the Universe immediately after the Big Bang was zero, thus requiring a separate process of baryogenesis) based on the argument that there was nothing before the Big Bang seems to be very naive and baseless, and possibly even fallacious. Either that or I am missing something very deep (not just that "nothing" means "baryon number is zero"), which is possible because I don't really understand this stuff. We need a citation to a reliable source to show that this reasoning (not just "nothing means zero baryon number") is commonly accepted as sound, or at least plausible, in the scientific community. That's what I'm saying. —Bkell (talk) 17:55, 15 December 2010 (UTC)

By the way, I do appreciate your responses. They have certainly helped me to clarify my thinking—I think the argument I was making at the beginning of the discussion was a lot murkier and less targeted than the argument I'm trying to make now. —Bkell (talk) 18:04, 15 December 2010 (UTC)

I know this is an old discussion but I got annoyed at the hard time that Bkell was given to get an apparently pretty simple (for somebody with a background in physics or mathematics) point across, while the actual argument he/she was trying to make was totally ignored. Taking the empty bag example, the point (as I read it) is that if you don't even have a bag then you cannot justify saying that this non-existent bag has zero apples. In fact, if we follow the mathematical convention that makes the most sense when talking about non-existent things (empty sets), any statement about the non-existent bag should be considered true (and for people without mathematical background this isn't at all intuitive or naive). For the universe this means that if the universe did not exist before the Big Bang, then its baryon number would have been 42 (or whatever else you want it to be) before the Big Bang. And there is absolutely no contradiction here with a baryon number of 0 for an existing universe; that would be like comparing apples and oranges... 110.23.118.21 (talk) 09:39, 25 January 2016 (UTC)

Two Universes

As I understand it, the recent theory of two universes being created together with zero entropy going in oposite time directions could easily answer the barion-antibarion asymetry.

• Two universes are created coincidently both having zero entropy initially.
  • One universe has increasing entropy in (what we percieve as) the forward time direction
  • The other has increasing entropy in the other time direction
• Baryons move forward in time (as wer percieve time). All baryons that were created close enough to time zero end up in our universe.
• Antibaryons move in the oposite time direction. All antibaryons that were created close enough to time zero end up in the other universe.

The movement (expansion) of the universe "forward" in time quickly eliminates the ability to communicate with the other universe (execpt posibly by gravitational influences). 18:12, 30 July 2015 (UTC)

Magnetic twist

http://www.dailygalaxy.com/my_weblog/2015/09/missing-antimatter-of-the-universe-mystery-solved-weekend-feature.html

Worth a mention? Hcobb (talk) 03:53, 14 September 2015 (UTC)

Merge with Baryon asymmetry

It's not clear to me why some theories are in this article and some are in the Baryon asymmetry article. Should the two be merged, or content moved between them?

Jruderman (talk) 23:48, 12 January 2017 (UTC)