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matter/antimatter doesn't fully annihilate...?


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What do you think?

 

http://news.yahoo.com/s/space/20100518/sc_space/whyweexistmatterwinsbattleoverantimatter

The seemingly inescapable fact that matter and antimatter particles destroy each other on contact has long puzzled physicists wondering how life, the universe or anything else can exist at all. But new results from a particle accelerator experiment suggest that matter does seem to win in the end.

 

The experiment has shown a small — but significant — 1 percent difference between the amount of matter and antimatter produced, which could hint at how our matter-dominated existence came about.

........

"Many of us felt goose bumps when we saw the result," said Stefan Soldner-Rembold, a particle physicist at the University of Manchester in the United Kingdom. "We knew we were seeing something beyond what we have seen before and beyond what current theories can explain."

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CP violation. It's one of the big questions still unanswered; the magnitude of the difference between matter and antimatter in these reactions is outside of the predictions of the standard model, and the size of deviations in previous experiments does not explain the asymmetry in our universe.

 

The article errs in implying that merely observing the asymmetry is a new result. It's been seen before.

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http://www.suntimes.com/lifestyles/health/2299276,CST-NWS-muons21.article

 

Using Fermilab's Tevatron particle accelerator, an international team of physicists found that high-energy collisions between protons and anti-protons produced more pairs of subatomic particles called muons than anti-muons.

The 1 percent difference between the number of muons and anti-muons could help explain why matter is more dominant in the universe than antimatter, said Stefan Soldner-Rembold, a particle physicist and spokesman for the research team.

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I really don't know what D0 are doing making so much hype about this result. The effect they see is (iirc) 3.2 sigma, so it is 'evidence' rather than a discovery. We have had plenty of other 3 sigma deviations from the Standard Model which went away with better statistics or error management. In fact, you would expect a 3 sigma deviation for one in twenty experiments even with the null hypothesis (that the SM is correct).

 

So this is way too early to get excited.

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I remember reading that article, but I assumed that the matter-antimatter fully annihilated, but then when matter-antimatter pairs were made from the energy afterwards, there was a slight tendency towards matter

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  • 2 weeks later...
CP violation. It's one of the big questions still unanswered; the magnitude of the difference between matter and antimatter in these reactions is outside of the predictions of the standard model, and the size of deviations in previous experiments does not explain the asymmetry in our universe.

 

The article errs in implying that merely observing the asymmetry is a new result. It's been seen before.

 

What is the B0 to Muon decay mode ? This paper is pretty opaque. In analogy w/ the Neutral Kaon (K0), the decay path is perhaps something such as (?):

 

[math]B^0 \to \pi^{+} \mu^{-} \bar{\nu}_{\mu}[/math]

 

[math](s \bar{d}) \to (u \bar{d}) \mu^{-} \bar{\nu}_{\mu}[/math]

 

as seen here:

 

300px-Quark_decays.svg.png

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