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not exactly too far away from Fukushima

Makes me wonder if the recent earthquakes put their aim off, possibly requiring recalibration at the sending end. I know this happens to radars after large quakes.

Pre-print here. They used data from the first two runs (Jan-Jun 2010 and Nov 2010-Mar 2011). I can guess why Run 2 ended when it did. The speculation about earthquakes and Fukushima contamination are unfounded.

Hmm, don't think so. This mixing can be nonzero (i.e. what they observed) and the CP violating phase could still be zero, in fact the T2K analysis assumes \delta_{CP} = 0 as there is currently no information on the CP violating phase. T2K's article

This is exactly what they do!! They're results are based on the observation of 6 electron neutrinos. The actual submitted article to Physical Review Letters, http://jnusrv01.kek.jp/public/t2k/node/2

Big problem, you can't aim, focus, or do anything other with neutrinos than create them.

That's not exactly true.

While you can't aim or focus neutrinos, you can create an aimed and focus pion beam. When the pions decay, you end up with an aimed and (slightly less) focused neutrino beam. If the pion beam is of significant energy, the neutrino beam will still be relatively tight.

I got a Ph.D. doing this as part of the K2K experiment in Japan.

The T2K http://jnusrv01.kek.jp/public/t2k/ experiment is basically a neutrino beam generator. A standard particle accelerator fires its beam into a target, generating a roughly collimated beam of neutrinos via a nuclear reaction. The neutrinos travel through the earth to the SuperK neutrino observatory where they are detected. So the signal is figured out. And every star generates photons as well. The problem isn't necessarily one of noise, it's of extinction. There are a lot of things in the galaxy which absorb photons really easily, making signals difficult to propagate. Neutrinos solve this part of the problem.

I worked briefly at a physics lab in Japan. It was some years ago, so it's possible that I'm misremembering, but as I recall they were very fond of macs. At any rate, they had plenty of the little things around.

Belle Confirms Quantum Entanglement at 10 Billion
Electron Volts.
http://www.kek.jp/intra-e/press/2007/BellePress9e. html

No, it wasn't an accelerator, and the experiment wasn't similar.

He/she was talking about the K2K experiment, which involved the Super-Kamiokande detector and a neutrino beam produced at the KEK facility.

I did my experimental particle physics PhD on an experiment named BaBar, you know, like the elephant. Are you telling me that isn't public-friendly?

A similar experiment based in Japan is called Belle and one in upstate NY called CLEO. One of the other experiments at the LHC is called ATLAS. They all seem reasonably public-friendly names (but then I am one of the folks you are saying don't know what a public-freindly name is, so I suppose my views are irrelevant).

As to the PR, it's pretty hard to make particle physics accessible to other physicists, let alone the general public. The essence of the question that BaBar and Belle were trying to answer is "Is CP violated in strong interactions?". It generally takes several years of university physics just to understand the question. The most "successful" PR projects never even seem to get to the crux of the project.

Incidentally, the answer is "yes, maximally". Your tax dollars at work!

Actually I was assuming he would find the one that I wrote in and amongst the other 170 hits found on Google.

Note: Please keep this undergraduate. I enjoy Physics, but my sub-atomic education is limited to a few books I've read.

I tend to go for the "we're spewing particles out of an accelerator just to see what happens and looking at the results in a roundabout way to extrapolate the existence of particles."

Extrapolate how? Looking at the results there appears to be an unaccounted-for mass concentration present in the reaction. If it's not a new type of particle then what? The evidence is there, now the task is to find an explanation for the phenomena.

The methods themselves are not questionable, but extrapolation such as this can easily lead to errors in conclusions drawn.

I think you are the one doing the erroneous extrapolation.

It's been around for years. You can buy one surplus for USD$20K. That's just the library and robot handling, not the tape drive.

sony brochure
more pictures

This is not a pointless experiment. In both experiments that the article mentions (SNO and SuperKamiokande) neutrinos are produced by a natural process (either nuclear reactions in the Sun or cosmic rays in atmosphere). There is always a possibility that we don't understand these natural processes good enough and that we misinterpret the data.

In these planned terrestrial neutrino oscillation experiments (such as NOMAD, K2K, OPERA, MINOS, etc.) neutrinos will be produced in controlled reactions on Earth, making interpretation and measurements easier, more precise and more model-independent.

(I imagine it's probably also kind of hard to aim, since neutrinos are so hard to see in the first place... They have a "front detector" at KEK which gives them an idea of how many neutrinos they're starting with, and I think where they're shooting them. KEK and Super-K are 250 km apart, so even a slight miss can have a big impact on whether they hit Super-K or not, I think.)

I'm not kidding. See, for example, this article.

World's biggest webserver!

From the any-port-in-a-storm-dept

Scientists at SuperKamiokande have ported Linux to run on the array of photomultiplier tubes in their huge underground neutrino detector.

What's more, they have even got Apache running! Check out their site being served direct from the detector here

CT: I wonder if it'll stand up to the slashdotting it's about to get!

The reason Japanese phones are smaller, lighter, and have longer battery life than American equivalents is because the cell size is much smaller.

Optimal cell size is a function of population density. In the Tokyo area, you've got about a billion people per square foot, so you can afford to keep the cell size small, which means you don't need a lot of power to transmit.

If you were to try to use the same cell size in a place like Texas, you'd be putting up more cell towers than there are people. It's just not economically feasable to do that.

Americans want phones they can take anywhere in the country and have them work. They need a big battery and a high power transmitter to make that work.

Here in the building where I work in Ibaraki-prefecture there's almost no cell coverage because we're a government lab (KEK) and you can't place a cell tower on government property according to Japanese law. People have to run to the roof whenever their cell phone rings. The lab isn't that big, either. It' can't me much more than a couple of square kilometers. Once you get off the lab, your phone works pretty much everywhere.

Don't expect to see Japan-sized phones in the U.S. any time soon. We need a ten-fold increase in population density before it will become practical.

SNO is a little different than SuperK because it's designed to see different types of neutrinos.

In SuperKamiokande, the target is simply water. Neutrinos come in, scatter off a nucleon, and produce a charged lepton (electron, muon, or tau) and this charged lepton produces cherenkov radiation. The works well for superk, since its goal is to measure neutrinos with energies above 5 MeV. Below that energy, the charged leptons just aren't energetic enough to travel far enough to produce enough light to be detected.

The purpose of SNO is to push the energy threshold down lower, to around 2 MeV. This can be done by adding a chemical scintillator to the target. Chemical scintillators become excited by the passage of high energy particles and emit light, so a typical low energy reaction in SNO will produced more light than one in SuperK.

Lowering the energy threshold is import if you want to study what goes on in the Sun because the fusion processes taking place produce a very particular neutrino spectrum. Because the fusion of hydrogen into helium doesn't occur in a single step, you can distinguish neutrinos coming from different stages of the reaction by their enery. Most of the neutrinos emitted from the sun are actually around 1 MeV and aren't energetic enough to even be seen by SNO, but SNO does a good job of observing more of the spectrum than previously seen by an experiment on this scale.

The experiment with the artificial neutrino beam that you refer to is K2K and it's still on going. Although K2K's results so far are not inconsistant with neutrino oscillations, it's just too early to tell. K2K will run for another three years to get enough data to make a conclusive statement.