Talk:Baryogenesis

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[edit] 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)

[edit] 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)

[edit] 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)

[edit] 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.

[edit] 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)