Buongiorno, Jan! 
To cut short, here it is the real thing - that is, the original article in arxiv:
http://static.arxiv.org/pdf/1109.4897.pdf
Anyway, I think it is good to be very very cautious. It is easy to accumulate 60 nsec of systematics.
Ciao, George
To cut short, here it is the real thing - that is, the original article in arxiv:
http://static.arxiv.org/pdf/1109.4897.pdf
Anyway, I think it is good to be very very cautious. It is easy to accumulate 60 nsec of systematics.
Ciao, George
Good paper. Here is my wild guess at a possible explanation: quantum tunneling. It has been known for a while that particles can tunnel through barriers at surprisingly high speeds, perhaps exceeding the speed of light. See paper by Paul Davies, for example. Neutrinos don't interact much, they just pass straight through things. What if some of the stuff they are passing through actually provides a potential barrier so they have to tunnel?
I said it was a wild guess. I can think of all sorts of snags, so it is probably wrong.
I said it was a wild guess. I can think of all sorts of snags, so it is probably wrong.
You might want to refresh that URL. There's a new file there dated 25 September 2011.
The URL is still valid, but it now comes to the opposite conclusion. Thanks for alerting me to this. A good example of science at work: a physicist publishes a criticism of someone else's finding, in turn someone points out a mistake in the criticism, but instead of blustering like a politician (or snake oil salesman) he retracts and explains his error.benb said:
There will probably be a few more examples like this, as the community struggles to understand what is going on.
There are three types of neutrino: electron type, muon type and tau type. They correspond to the three leptons. There appears to be a correspondence between these six (leptons plus their neutrinos) and the six flavours of quark (u,d,s,c,t,b), although the reason for this is still obscure. There are also anti-neutrinos, although I think it is still unclear whether these are distinct particles or identical to their opposite number.
When a muon decays into an electron, it also emits a muon neutrino and an electron antineutrino. This is similar to beta decay of a nucleon.
When a muon decays into an electron, it also emits a muon neutrino and an electron antineutrino. This is similar to beta decay of a nucleon.
I see that out of kind generosity towards the questioner, You had kindly slipped over the fact that neutrinos also like to oscillate, being born as a special flavor, after some distance showing up as another one, like from muon to tau neutrino, or like in the MSW zone in the sun, from electron to muon / tau neutrino
No, not kindness, but forgetfulness! Yes, neutrinos oscillate to different flavours. This is why the orginal solar neutrino experiment found only a third of the expected number. There are one or two other particles which do this, such as the neutral kaon. This strange behaviour comes straight from quantum mechanics, because (unlike most particles) the mass eigenstates are different from the quantum number eigenstates.
Particle physics went though an interesting stage in the 1970s (when I was briefly involved in it). New things were appearing, such as charm. Then it settled down for a few decades, as the details were filled in (e.g. more quarks) but nothing especially surprising happened. It was mainly more of the same. Now things seem to be hotting up again. Maybe there will be some real advances/changes in physics over the next 10 years.
Particle physics went though an interesting stage in the 1970s (when I was briefly involved in it). New things were appearing, such as charm. Then it settled down for a few decades, as the details were filled in (e.g. more quarks) but nothing especially surprising happened. It was mainly more of the same. Now things seem to be hotting up again. Maybe there will be some real advances/changes in physics over the next 10 years.
I'm a self-educated layman myself, and I think the answer is no. Different types can be detected differently, but it looks like they're not hugely different, at least as far as your next question. I found some interesting reading about detecting the Sun's neutrinos here:
Standard Solar Model - Wikipedia, the free encyclopedia
As I understand it, the difference isn't necessarily between types of neutrinos - they all go at the speed of light (or if the story in this thread is true, 0.0025 percent faster), and they're all VERY weakly interactive with matter. Perhaps some types are more weakly interactive than others, but as far as I know that's not important here.
The really big difference between LHC neutrinos and supernova neutrinos is quantity, by many, many orders of magnitude. I can't find numbers offhand, but this description is fascinating:
Supernova - Wikipedia, the free encyclopedia
I'd like to know how many times of neutrinos that is compared to the burst of neutrinos in this experiment. It would be ten-to-the-N, and I'd like to know what N is. Regardless, it's one hell of a lot of neutrinos.
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None of them go at the speed of light. Because of their tiny mass, they were expected to go very slightly slower than the speed of light. Only massless particles go at rhe speed of light. They are different from each other, and have some different reactions, which is how they can be distinguished. Speed is not one of the differences, as it is not a defining characteristic of a particle (or anything else).benb said:
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