New result from Fermilab

[Lincoln]

Fermilab scientists have found significant evidence for a preference in the universe for matter over antimatter. The story is still incomplete, but this could be a big deal. The experiment who made the discovery is the DZero collaboration. I'm told that they have a noteworthy scientist or two among their ranks.

[wolfhnd]

As a lay person I don't see any significance to this finding, could you explain the possible ramifications?

[Lincoln]

You've undoubtedly heard of E = mc². People say (imprecisely) that this means that matter can be converted into energy and vice versa. This is not quite correct. Energy can be converted into matter and antimatter in precisely equal quantities. That's fact #1.

Fact #2 is that in the early universe, energy was abundant. Through it, matter and antimatter were created inequal quantities.

Fact #3 is that the universe appears to be made exclusively of matter.

Question #1 is "So where the hell did all the antimatter go?"

Over the last 30-40 years, evidence has mounted that something made a small imbalance of matter and antimatter. For every 1,000,000,000 antimatter particles, there was 1,000,000,001 matter particles. The billions cancelled out, leaving 1 matter particle.

So how did this occur? Nobody knows in detail. Since 1964, we've known of small effects in which matter is favored over antimatter. This occurs in complex ways and the effect is insufficient to explain what we see.

This new result is more information in the story. Matter is favored over antimatter in a complex and subtle assertion of quantum mechanical principles.

The guy behind this analysis is someone who I've known for 15 years. He used to talk about the measurement in our older data set (some 1/70 of what we have now.) He kept up the analysis and the result continued to look promising. Assuming that everything is modelled correctly, there is a 0.1% chance that this effect could be accidental. (That's a big assumption, but we've hammered on the analysis for a long time.)

When you look at thousands of plots, it's inevitable that you will see a few plots with effects that are only 0.1% likely. So I would ordinarily dismiss this as one of those. But this statistical argument is invalid because it's not thousands of plots. It's a single plot which has retained its statistical power for 15 years. Further the statistical power has grown.

It's possible that the guy behind the analysis simply selected the data in a way that reinforced his ideas of 15 years ago, but he has a co-worker who is one of our best and brightest. In addition, the analysis has been vetted by at least a hundred physicists, including me. So far, the analysis has resisted all our attempts to kill it.

So it might be real and this might be historic. It will take more data to be definitive. But it's definitely interesting.

[Marshall]

The next DZero "Result of the Week" is (I guess from the biweekly pattern of alternation) not due to come out until 27 May.
http://www.fnal.gov/pub/today/resultoft ... index.html
Maybe there will be some kind of special article in the Fermilab daily? Or a recap in the 27 May issue?
Looking forward to seeing it.

What I could find so far is that Fermilab Today
http://www.fnal.gov/pub/today/
besides a brief press release-like 18 May announcement
http://www.fnal.gov/pub/presspass/press ... 00518.html
has republished something from Ars Technica:
http://arstechnica.com/science/news/201 ... matter.ars

[Lincoln]

As it happens, I can 100% guarantee that the Result of the Week for March 27 will cover this. The ROW ping-pongs between CDF and DZero. Tomorrow is CDF's turn. You can easily identify the two. DZero's are the one with the gifted writing and deft art.

However, you should keep in mind that the ROW is very brief and the target audience are the secretaries and the guys on the loading dock at the Lab. We recognize that others read it, including well-educated people. But they are an ancillary audience.

You may want to look at this:

http://www.fnal.gov/pub/today/archive_2010/today10-05-18.html

The Fermilab Today URL you cite gets updated each day.

[Marshall]

...

You may want to look at this:

http://www.fnal.gov/pub/today/archive_2010/today10-05-18.html

That's the same Rhianna press release that I gave a link to
http://www.fnal.gov/pub/presspass/press ... 00518.html

It is just two links to the same thing.

I'm glad that the unnamed author of the 27 May ROW is planning to do an article on the CP-violation report and am looking forward to seeing it.

[Lincoln]

I actually heard that the ROW might be more personality-centric than normal. This is still under negotiation. It may be that there are two articles: one physical and one personality.

[Lincoln]

I notice that the DZero Result of the Week article is available for your viewing pleasure.

http://www.fnal.gov/pub/today/archive_2010/today10-05-27.html

The ROW ended up not being personality-centric.