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" In 1931 Enrico Fermi renamed Pauli's "neutron" to neutrino as a word play on neutrone, the Italian name of the neutron. (Neutrone in Italian means big and neutral, and neutrino means small and neutral.) " http://icecube.wisc.edu/info/neutrinos/1931?iframe=true&width=70%&height=100% cernotr

But in September 2011 workers at CERN, the world's largest physics lab, announced they had recorded subatomic particles travelling faster than the speed of light. They recorded neutrinos travelling at 300,006 kilometres per second in a 450-mile underground tunnel between Switzerland and Italy. Light travels at 299,792 kilometres per second. icebrg

Professor Sarkar said: “We are being a little restrained about what we have found as we have more results to go through but we are confident these are extraterrestrial high energy neutrinos. “What we are seeing, however, is quite literally the tip of an iceberg and it will be exciting to see what we can learn from the results.” lowhigh

Until now, they have seen low-energy neutrinos that originate in Earth’s atmosphere, neutrinos from farther out within the Solar System, and neutrinos from one rare nearby supernova, known as 1987A. The 28 neutrinos observed by IceCube – a particle detector made from one cubic kilometer of ice in Antarctica – are different. They are at a significantly higher energy level than those produced by the previously measured sources.They were found in data collected from May 2010 to May 2012. In analyzing more recent data, the IceCube Collaboration discovered another event (dubbed Big Bird) that was almost double the energy of Bert and Ernie. bb_p

In the third year of data, not reported in the Science paper, an even more energetic neutrino appeared. That one is called Big Bird. Dr. Halzen said some of the 28 might have come from our own Milky Way galaxy, but others originated farther away. “Some of them are certainly extragalactic,” he said. IceCube detects only one out of a million neutrinos, which means about 28 million neutrinos from outside the solar system passed through during that time. Because neutrinos so rarely collide with anything, detecting them requires a great deal of material — in the case of IceCube, the vast expanse of ice readily available at the South Pole. Once in a great while, a neutrino does collide with something, setting off a cascade of electrons and other subatomic debris. Charged particles in a transparent material like ice give off blue light. Phototubes record the bursts of light, and from the patterns, scientists can determine the direction and energy of the incoming neutrinos. Although IceCube is not tuned to find the low-energy neutrinos from supernovas in the galactic neighborhood, another explosion like the one observed in 1987 would be a bonanza for IceCube. It would register about 100,000 neutrinos, Dr. Halzen said. Until now, most telescopes have looked at the universe by gathering photons, or particles of light, including lower-energy radio waves, visible light, X-rays and gamma rays. The very-high-energy neutrinos detected by IceCube open a new spectrum for observing the universe. With more observations, the scientists hope to be able to determine where the neutrinos originated, whether from black holes or the rapidly rotating burned-out stars known as pulsars. bb

Halzen said the team is already using the new tactic to look through their 2013 data. They have found at least one more high-energy neutrino, the most powerful one yet seen, which they are calling “Big Bird.” Halzen said he expects to have enough neutrinos to say something about cosmic accelerator within about five years. The findings are generating a good deal of excitement in the neutrino astrophysics community. “I think this paper is one that will go into the textbooks,” said physicist John Learned of the University of Hawaii, who is not involved in IceCube. “It will be recognized as the beginning of high-energy neutrino astronomy.” movie

One of the biggest undertakings in PSL history, the IceCube project is a neutrino observatory at the South Pole. The project called for the design and construction of over 4,000 Digital Optical Modules(DOM) to be placed at depths of up to 2,400 meters below the surface of the ice, which is about 2,500 meters thick. The optical modules are designed and fabricated to survive the incredibly harsh environment in which they are deployed. They must also have nearly perfect reliability to continue operation in this environment for at least 20 years. The holes were drilled with the Enhanced Hot Water Drill. This complex device is the single largest piece of equipment at the South Pole. It must drill the holes in an accurate and rapid manner, while maintaining a high level of reliability and energy efficiency. PSL was the main design, construction, testing, and staging facility for the IceCube project from the start and continued its involvement during deployment. Many PSL employees traveled to the South Pole and assisted during deployment seasons. 3t

The number of events is too small to pinpoint the origin of the neutrinos, however. "We do not yet have the number of neutrinos with which could paint a picture of the sky in the 'light of neutrinos,'" said Katz, who is leading the design of a rival neutrino observatory called KM3net, to be built underneath the Mediterranean Sea. The next step will be answering questions such as where the neutrinos come from, what their energies are and what "flavor" they are (neutrinos come in three types). As IceCube gathers more data, " All of these questions are now starting to be addressed," Katz said. team

“These are the first indications of neutrinos from outside our solar system,” says TUM physicist Professor Elisa Resconi, who is a member of the IceCube collaboration. “These events can be explained neither by causes like atmospheric neutrinos, nor by other high-energy events like muons created in the Earth’s atmosphere during interactions with cosmic rays.” IceCube observatory in Antarctica Photo: Emanuel Jacobi/NSF After observing hundreds of thousands of atmospheric neutrinos, the researchers are finally convinced they have proven the existence of neutrinos that fulfill their expectations of astrophysical neutrinos that in all likelihood stem from cosmic accelerators. “Now we must determine where these neutrinos come from and how they are created. We are at the frontier of a new astronomy with neutrinos,” says Elisa Resconi. The IceCube observatory is melted into the permafrost of the South Pole, an installation that was completed in 2010 following seven years of construction. At one cubic kilometer in size, it is the largest neutrino detector worldwide. 86 vertical wire ropes with a total of 5160 optical sensors were sunk 1450 to 2450 meters into the ice. IceCube detects neutrinos via tiny flashes of blue light, so called-Cherenkov radiation, which appears when neutrinos interact with ice, generating a shower of charged particles. The observatory is run by an international consortium under the direction of the University of Wisconsin, Madison (USA). The research team comprises some 250 scientists and engineers from USA, Germany, Sweden, Switzerland, Japan and other countries. pixel

UW-Madison physics Professor Francis Halzen is principal investigator on the IceCube project. He says the neutrinos are much more energized that ones located in 1987 when a star exploded, and probably needed a very big accelerator — a cosmic one — to get here. “There's basically only one idea around, that they somehow originating near a black hole or maybe a pulsar: some very extreme object.” A black hole is a place in space with a very strong gravity pull. A pulsar is a rotating star that sends out beams of radiation. This is the highest energy neutrino ever observed, with an estimated energy of 1.14 PeV. It was detected by the IceCube Neutrino Observatory at the South Pole on January 3, 2012. IceCube physicists named it Ernie. This is the highest energy neutrino ever observed, with an estimated energy of 1.14 PeV. It was detected by the IceCube Neutrino Observatory at the South Pole on January 3, 2012. IceCube physicists named it Ernie. Halzen says researchers have determined the far traveling neutrinos did not come from the Earth's atmosphere. He says now that scientists have a better way to take what he calls 'a picture of the sky,' more pictures will be taken. “We have a map of the sky with only 28 pixels in it. Our job now is to accumulate these events at as high a rate as possible, so we can get a map that we can actually read.” fonotomo

The magic of neutrinos There's a kind of magic that surrounds neutrinos: They're ghostly particles that rarely interact with matter, which means they're devilishly difficult to detect. Even if you can detect them, it's hard to distinguish between the cascades of neutrinos created by cosmic rays shooting through the atmosphere and the neutrinos from more exotic sources. That's why more than 5,000 sensitive detectors were buried about a mile down (1.5 kilometers) in the South Pole's ice. When neutrinos interact with the ice, they spark another kind of particle called a muon, and the muons radiate an ultra-faint blue glow. IceCube's detectors are sensitive enough to measure that glow, and the collaboration's scientists can analyze patterns and intensities of the muon radiation to determine the direction and energy of the neutrinos. Mapping the cosmic flow of neutrinos could produce a radically different picture of the universe around us. metomu

We have isolated a sample of neutrinos by rejecting background muons from cosmic ray showers in the atmosphere, selecting only those neutrino candidates that are first observed in the detector interior rather than on the detector boundary. This search is primarily sensitive to neutrinos from all directions above 60 TeV, at which the lower-energy background atmospheric neutrinos become rare, with some sensitivity down to energies of 30 TeV. Penetrating muon backgrounds were evaluated using an in-data control sample, with atmospheric neutrino predictions based on theoretical modeling and extrapolation from previous lower-energy measurements. images

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