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  • richardmitnick 3:36 pm on July 25, 2016 Permalink | Reply
    Tags: , , Neutrinos, , , TH2K, VA Tech   

    From phys.org: “CP violation or new physics?” 


    July 25, 2016
    Lisa Zyga

    This is the “South Pillar” region of the star-forming region called the Carina Nebula. Like cracking open a watermelon and finding its seeds, the infrared telescope “busted open” this murky cloud to reveal star embryos tucked inside finger-like pillars of thick dust. Credit: NASA/Spitzer

    Over the past few years, multiple neutrino experiments have detected hints for leptonic charge parity (CP) violation—a finding that could help explain why the universe is made of matter and not antimatter. So far, matter-antimatter asymmetry cannot be explained by any physics theory and is one of the biggest unsolved problems in cosmology.

    But now in a new study published in Physical Review Letters, physicists David V. Forero and Patrick Huber at Virginia Tech have proposed that the same hints could instead indicate CP-conserving “new physics,” and current experiments would have no way to tell the difference.

    Both possibilities—CP violation or new physics—would have a major impact on the scientific understanding of some of the biggest questions in cosmology. Currently, one of the most pressing problems is the search for new physics, or physics beyond the Standard Model, which is a theory that scientists know is incomplete but aren’t sure exactly how to improve. New physics could potentially explain several phenomena that the Standard Model cannot, including the matter-antimatter asymmetry problem, as well as dark matter, dark energy, and gravity.

    As the scientists show in the new study, determining whether the recent hints indicate CP violation or new physics will be very challenging. The main goal of the study was to “quantify the level of confusion” between the two possibilities. The physicists’ simulations and analysis revealed that both CP violation and new physics have distributions centered at the exact same value for what the neutrino experiments measure—something called the Dirac CP phase. This identical preference makes it impossible for current neutrino experiments to distinguish between the two cases.

    “Our results show that establishing leptonic CP violation will need exceptional care, and that new physics can in many ways lead to non-trivial confusion,” Huber told Phys.org.

    The good news is that new and future experiments may be capable of resolving the issue. One possible way to test the two proposals is to compare the measurements of the Dirac CP phase made by two slightly different experiments: DUNE (the Deep Underground Neutrino Experiment) at Fermilab in Batavia, Illinois; and T2HK (the Tokai to Hyper-Kamiokande project) at J-PARC in Tokai, Japan.


    Proposed TH2K

    “The trick is that the type of new physics we postulate in our paper manifests itself in the way in which neutrino oscillations are affected by the amount of earth matter through which the neutrino traverses,” Huber said. “The more matter travelled through, the larger the effect of this type of new physics.”

    “Now, for DUNE, neutrinos would have to travel roughly 1300 km in the earth, whereas for T2HK they would travel only about 300 km. Thus one would find two different values for the Dirac CP phase in both cases, indicating a problem.”

    In order to be accurate, these experiments will require extremely high degrees of precision, which Huber emphasizes should not be overlooked.

    “Of course, the same result could arise if for some reason either experiment was not properly calibrated and thus precisely calibrating these experiments will be extraordinarily important—a very difficult task, which I believe is not quite getting the attention it should.”

    See the full article here .

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

  • richardmitnick 10:35 am on July 22, 2016 Permalink | Reply
    Tags: , , Neutrinos, U Wisconsin IceCube   

    From IceCube: “IceCube search for cosmogenic neutrinos favors heavy nuclei cosmic-ray sources” 

    IceCube South Pole Neutrino Observatory

    21 Jul 2016
    Silvia Bravo

    The highest energy cosmic rays are known to reach energies a trillion times larger than those of protons in the LHC at CERN. These ultra-high-energy cosmic rays (UHECR) can produce neutrinos with energies above 100 PeV either by the interaction with photons and matter at the source, which are just very high energy astrophysical neutrinos, or by the interaction with the cosmic microwave background (CMB), which are referred to as cosmogenic neutrinos.

    The IceCube Collaboration has made public today that a new search for cosmogenic neutrinos resulted in two very high energy neutrinos. These neutrinos, which are found to be of astrophysical origin with a 92.3% probability, include the highest energy neutrino detected to date. While of astrophysical origin, the energy of these neutrinos does not match the expectation for a cosmogenic neutrino flux. The lack of evidence for such events in a search of seven years of IceCube data places very strong constraints on the sources of UHECR. Proton-dominated sources are greatly disfavored, and testing mixed and heavy nuclei cosmic-ray sources will require much bigger instruments, such as an extension of IceCube or radio Askaryan neutrino detectors. These results have been submitted yesterday to Physical Review Letters.

    All-flavor-sum neutrino flux quasi-differential 90%-CL upper limit on one energy decade E^−1 flux windows. Credit: IceCube Collaboration

    Cosmogenic neutrinos, with energies reaching up to 50 EeV or more, are expected to be the highest energy neutrinos in nature. Their flux is supposed to exceed that of astrophysical neutrinos at energies of at least 100 PeV and above. But no one has ever detected a cosmogenic neutrino, not even a neutrino with an energy above 10 PeV.

    The results presented today by the IceCube Collaboration, using data from 2008 to 2015, have once more indicated a fruitless search for cosmogenic neutrinos. And, although this is not a totally unexpected scenario, it does set very strong constraints on the sources of UHECRs.

    Previous measurements of the spectrum and chemical composition of UHECRs by HiRes and the Telescope Array suggested a chemical composition compatible with proton-dominated sources up to the highest energies. However, Auger’s results pointed to the need for heavier nuclei UHECR to explain its data. IceCube results now confirm Auger’s hints and reject UHECR sources such as proton-dominated models of active galactic nuclei (AGNs) and gamma-ray bursts (GRBs).

    “Many scientists thought that AGNs or GRBs would be the standard scenario of UHECR production,” says Aya Ishihara, an IceCube researcher at Chiba University in Japan and the corresponding author of this work. “But neutrinos are changing our view of the ultra-high-energy universe,” adds Ishihara.

    Continued searches should now concentrate on models with weak or no cosmological evolution proton-dominated sources and those with heavier nuclei composition or, as most scientists lean toward, a combination of both. But these scenarios push cosmogenic neutrinos far below the detection threshold of any running detector.

    The production of cosmogenic neutrinos in muon and pion decays produced in the interaction of primary cosmic rays with CMB photons is efficient only if UHECR are protons. Models with a strong cosmological evolution of proton-dominated sources predict a flux of cosmogenic neutrinos in IceCube’s sensitivity region above 100 PeV. But these are now rejected by IceCube results.

    In the case of heavier nuclei, these CR interactions are suppressed and the neutrino flux falls rapidly with energy. “Neutrinos become more important if UHECRs are heavy nuclei since, due to the unknown magnetic fields in galactic and extragalactic environments, the cosmic rays’ path is even more unpredictable than for protons. But, no matter what, neutrinos always point to their sources,” states Ishihara.

    The more UHECRs are heavy nuclei, the smaller the EeV component of the cosmogenic neutrino flux, and the larger the detector required to first detect them. IceCube results strongly support the need for a full deployment of experiments such as ARA and ARIANNA , which are currently either in partial deployment or running as a pilot experiment.

    A partially contained cascade with a deposited energy of 0.77 PeV was detected in IceCube on November 16, 2012. Credit: IceCube Collaboration

    This is the highest energy neutrino event, detected in IceCube on June 11, 2014. The event deposited 2.6 PeV in the detector. Credit: IceCube Collaboration

    The search for cosmogenic neutrinos did find two very high energy neutrinos. One is a track with a deposited energy of 2.6 PeV, which had already been found in a previous study and is the highest energy neutrino recorded to date. The second is a partially contained cascade with a deposited energy of 0.77 PeV.

    The hypothesis that these events are of cosmogenic origin is rejected by IceCube researchers at more than a 99% confidence level. These are most likely astrophysical neutrinos since the probability of being atmospheric in origin has been determined to be very small.

    The track was detected in June 2014 and deposited some energy outside the detector. IceCube scientists estimated that the neutrino that induced this event had an energy about three times greater than what was deposited in the detector, i.e., the energy of the initial neutrino was well above 5 PeV.

    + Info Constraints on ultra-high-energy cosmic ray sources from a search for neutrinos above 10 PeV with IceCube, The IceCube Collaboration: M.G.Aartsen et al, Submitted to Physical Review Letters, arxiv.org/abs/1607.05886

    See the full article here .

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    ICECUBE neutrino detector
    IceCube is a particle detector at the South Pole that records the interactions of a nearly massless sub-atomic particle called the neutrino. IceCube searches for neutrinos from the most violent astrophysical sources: events like exploding stars, gamma ray bursts, and cataclysmic phenomena involving black holes and neutron stars. The IceCube telescope is a powerful tool to search for dark matter, and could reveal the new physical processes associated with the enigmatic origin of the highest energy particles in nature. In addition, exploring the background of neutrinos produced in the atmosphere, IceCube studies the neutrinos themselves; their energies far exceed those produced by accelerator beams. IceCube is the world’s largest neutrino detector, encompassing a cubic kilometer of ice.

  • richardmitnick 7:49 am on July 20, 2016 Permalink | Reply
    Tags: , , Neutrinos   

    From FNAL: “Mix and mass: teasing out neutrino transformations” 

    FNAL II photo

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    July 14, 2016
    Fernanda Psihas

    In its recent update NOvA recorded 33 electron-neutrino event candidates at its far detector (grey band). That measurement is compared to expectations for normal (blue) and inverted (red) mass hierarchies as a function of the CP-violating phase δCP. CP violation is largest when δCP takes on values of π/2 and 3π/2 and absent for values of 0, π and 2π.

    It is an exciting time to be a neutrino physicist. At the start of the century, the neutrino experiments Super-K, based in Japan, and SNO, based in Canada, revealed the phenomenon of oscillations, lifting the veil on many neutrino mysteries. Rather than closing the case on neutrinos, this game-changing, Nobel Prize-winning discovery opened a realm of possibilities for scientists to further investigate their nature.

    Super-Kamiokande Detector
    Super-Kamiokande Detector, Japan

    SNOLAB, Sudbury, Ontario, Canada.
    SNOLAB, Sudbury, Ontario, Canada

    “Oscillation” is how scientists describe the way neutrinos transform from one of their three types into another. The three types are called electron, muon and tau.

    When the NOvA experiment was first conceived in the early 2000s, muon neutrinos were known to transform mostly into tau neutrinos. NOvA measures the small fraction of the muon neutrinos produced at Fermilab that also oscillate into electron neutrinos on their 810-kilometer trip to a detector at Ash River, Minnesota.

    FNAL/NOvA experiment
    FNAL, NOvA map

    This fraction gives us insight into some important questions:

    1. Are there two light and one heavy neutrino, or vice versa? The first scenario is called the normal hierarchy, and the second the inverted hierarchy. This difference shows up during the voyage through the matter of the Earth’s crust and means that muon neutrinos and antineutrinos oscillate into electron neutrinos at different rates.
    2. Are the oscillations of neutrinos and antineutrinos intrinsically different? Differences between the behavior of matter and antimatter particles are said to violate CP symmetry. CP violation in neutrinos could help explain why the universe is made out of matter and not antimatter.

    Fermilab is producing record numbers of neutrinos for NOvA. But, of course, there is a catch: Of the roughly 10 billion trillion neutrinos produced, only a handful of them interact in the detector at Minnesota. And with 150,000 cosmic-ray particles crossing the detector every second, finding the neutrinos that come from the Fermilab accelerator complex is “winning the lottery” meets “needle in a haystack.” To find its neutrinos, NOvA uses a novel technique based on advances in computer vision technology, which automatically categorizes cosmic-ray and neutrino event pictures in a way inspired by the human eye.

    NOvA released new results on the rate of electron neutrino appearance at the XXVII International Conference on Neutrino Physics and Astrophysics, or Neutrino 2016, which ended last week. NOvA observed 33 electron neutrinos appearing in its muon neutrino beam; without oscillations, only eight counts from backgrounds would have been expected. This rate is close to the maximum expected in standard three-flavor oscillation scenarios and, in combination with constraints from the muon neutrino disappearance result also reported last week, prefers the normal hierarchy and large CP violation. Although this preference is not yet statistically significant, the new results rule out a range of possibilities in the inverted hierarchy scenario helping narrow in on the correct solution.

    NOvA will continue to take data using neutrinos until spring 2017, when it will switch to using antineutrinos. New clues about the differences between neutrino and antineutrino oscillations may be just around the corner.

    Chris Backhouse of Caltech will present NOvA results at Fermilab in a special Joint Experimental-Theoretical Seminar on Wednesday, July 20.

    See the full article here .

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    Fermilab Campus

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.

  • richardmitnick 9:31 am on July 15, 2016 Permalink | Reply
    Tags: , , Neutrinos, PINGU   

    From IceCube: “Rethinking PINGU, a world-class instrument for neutrino oscillation studies” 

    IceCube South Pole Neutrino Observatory

    15 Jul 2016
    Sílvia Bravo

    IceCube is usually presented as the world’s largest neutrino detector. And it is. But IceCube is much more, it is a multipurpose instrument detecting neutrinos from around 10 GeV to PeV and above. Thus, IceCube is also a particle physics detector playing a leading role in neutrino physics.

    As IceCube data is continually analyzed to advance our understanding of neutrino astronomy and physics, scientists are already thinking about the future. And when talking about neutrino oscillations, dark matter searches, supernova neutrino bursts, or probing the composition of the Earth’s core, GeV-scale neutrinos become our most desired particles.

    The Precision IceCube Next Generation Upgrade (PINGU) is the proposed infill extension in a region at the center of the IceCube Neutrino Observatory that will lower the energy threshold to a few GeV, dramatically increasing both the number of GeV-scale neutrinos detected by IceCube and, more importantly, the precision with which they are measured.

    The atmospheric neutrino oscillation contours are shown under assumption of normal ordering, including projected sensitivities from NOVA and T2K. Image: IceCube-Gen2 Collaboration

    Although PINGU is not a new idea, scientists have now optimized its design, lowering the cost and deployment logistics without compromising its science reach.

    Proposed baseline geometry for PINGU. PINGU sensors will be arranged in a dense configuration inside of the current IceCube array.

    PINGU’s new design reduces the number of strings from 40 to 26, allowing the deployment of the full detector in only two polar seasons. However, the number of sensors on each string will increase up to 192, providing a 6 Mton effective mass neutrino detector and improved sensitivity. The new design lowers the cost by over $20 million. Further upgrades to this design, not yet fully explored, could entail using multi-PMT sensors such as the ones currently used in KM3NeT, which could improve sensitivity and resolution while reducing the cost even further.

    Schematic layout of PINGU within the IceCube detector. In the top view inset at right, red crosses show proposed PINGU string locations. PINGU modules would be deployed in the clearest ice at the bottom of the detector. Image: IceCube-Gen2 Collaboration

    PINGU will explore neutrino oscillation physics in an energy range not fully explored by long-baseline neutrino beam experiments. Researchers expect to test the maximal mixing hypothesis, i.e., that the third neutrino is composed of exactly equal amounts of muon and tau neutrinos, and determine the mass ordering, i.e., whether the third neutrino is much lighter or heavier than the other two, with a significance of 3 sigma within four years.

    PINGU will also greatly advance the measurements of the atmospheric neutrino oscillation parameters, for which the current IceCube configuration has already proven to be very competitive with dedicated neutrino oscillation experiments. The construction and science outcomes of PINGU require the efficient and successful deployment of a new detector at the South Pole that will build on the previous outstanding experience of IceCube. The instrumentation design, drilling, deployment, and operations are well understood and have already shown to be feasible with enormous success.

    The letter of intent presented this week has optimized the design to make PINGU an affordable detector that could be fully operational as early as five years from now. Now that scientists know that this is possible, they are also exploring how far the scientific program could go. “Best of all, PINGU will use a fundamentally different technique to study this type of physics, which makes it a vital cross-check on measurements made by other neutrino experiments,” explains Ty DeYoung, a researcher at Michigan State University and one of the members of the IceCube-Gen2 Collaboration leading the work on PINGU. “There are many theories of new physics that could be tested by comparing PINGU observations to those made by other experiments—indeed, that might be the only way to test some of these theories,” adds DeYoung.

    The detection of lower energy neutrinos will expand IceCube searches for dark matter annihilation as well as develop a new tomographic probe of the Earth’s composition using matter effects on neutrino oscillations. Also, the increased number of sensors will enhance the sensitivity to the low-energy neutrinos created by supernova bursts.

    The PINGU Collaboration is already working on a more comprehensive document, which will be available in the near future.

    + info PINGU: A Vision for Neutrino and Particle Physics at the South Pole, IceCube-Gen2 Collaboration: M. G. Aartsen et al. arxiv.org/abs/1607.02671

    See the full article here .

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    ICECUBE neutrino detector
    IceCube is a particle detector at the South Pole that records the interactions of a nearly massless sub-atomic particle called the neutrino. IceCube searches for neutrinos from the most violent astrophysical sources: events like exploding stars, gamma ray bursts, and cataclysmic phenomena involving black holes and neutron stars. The IceCube telescope is a powerful tool to search for dark matter, and could reveal the new physical processes associated with the enigmatic origin of the highest energy particles in nature. In addition, exploring the background of neutrinos produced in the atmosphere, IceCube studies the neutrinos themselves; their energies far exceed those produced by accelerator beams. IceCube is the world’s largest neutrino detector, encompassing a cubic kilometer of ice.

  • richardmitnick 8:19 am on July 13, 2016 Permalink | Reply
    Tags: , , , Neutrinos   

    From AAAS: “Massive neutrino experiment undermines our sense of reality” 



    Jul. 12, 2016
    Adrian Cho

    The test of fundamental quantum theory comes as an unexpected bonus from data collected with the massive Main Injector Neutrino Oscillation Search neutrino detector. R. Hahn/Fermilab

    Data from a massive neutrino experiment show that the elusive subatomic particles must literally be of two mutually exclusive types at once—poking a hole in our intuitive sense of reality. The result is bedrock quantum mechanics. But it’s the sort of thing typically shown with highly controlled quantum optics experiments and not with nearly undetectable neutrinos.

    “If you had told me 10 years ago that we would use neutrinos to study quantum foundations, I would have said that you’d been smoking something very exciting,” says Andrew White, a physicist at the University of Queensland, St. Lucia, in Brisbane, Australia, who was not involved in the work. “The result is utterly unsurprising and yet utterly attractive because it tells us that there’s a new system for testing quantum foundations.”

    According to quantum theory, minuscule things behave nothing like everyday objects. Unlike an apple, a subatomic particle can be in two places or of two different types at once. Those two-way “superposition” states are fragile, however. Measure, say, a particle of light or photon that is simultaneously polarized both horizontally and vertically and it will randomly “collapse” one way or the other.

    Still, according to quantum theory, the photon’s polarization doesn’t exist until it’s measured. Albert Einstein disdained that idea, arguing that a physical property of an object has to be “an element of reality” that exists independently of measurement. To salvage “realism,” some physicists argued that the result of such a measurement is predetermined by some “hidden variable” within the photon.

    In 1964, U.K. theorist John Bell devised a way to test that notion. In quantum theory, two photons in two-way states can be “entangled” so that a measurement on one instantly determines not only its polarization but that of the other photon as well, even if it’s light-years away. That quantum connection produces correlations between the particles that are stronger than hidden variables allow, Bell showed. Last year, physicists in the Netherlands and the United States performed the best demonstrations yet of those correlations, nixing such hidden variables.

    The test with neutrinos involves correlations between measurements separated not in space, but in time. In 1985, theorists Anupam Garg, now at Northwestern University, Evanston, in Illinois, and Anthony Leggett of the University of Illinois, Urbana-Champaign, considered repeated measurements of a single quantum system: a ring of superconductor in which an unquenchable current flows one way or the other. The ring mimics a coin, which can be heads or tails, except that current can also flow both ways at once.

    According to quantum theory, the current will oscillate between the two directions. So a measurement will reveal it flowing, say, clockwise, with a probability that depends on the time. Leggett and Garg found that certain correlations among three or more measurements would be stronger than classical physics allows—if the current has no direction until it’s measured.

    Experimenters have approximated the Leggett and Garg test. In 2011, White and colleagues demonstrated the extrastrong correlations in quantum optics, although in an average way and not with a single photon. Now, Joseph Formaggio, a neutrino physicist at the Massachusetts Institute of Technology in Cambridge, and colleagues provide a demonstration using data from the Main Injector Neutrino Oscillation Search (MINOS) experiment at Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, which fires neutrinos at near-light-speed 735 kilometers to a 5.4-kiloton detector in the Soudan Mine in Minnesota.

    FNAL Minos Far Detector

    Neutrinos come in three flavors that morph into one another. Those fired from Fermilab start as so-called muon neutrinos and “oscillate” mainly to electron neutrinos in a process that resembles the one analyzed by Leggett and Garg. MINOS experimenters didn’t repeatedly measure individual neutrinos, as detecting a neutrino destroys it. However, each neutrino starts in the same state whose evolution depends only on the time since it left Fermilab. So measuring many neutrinos was equivalent to measuring the same one repeatedly.

    The MINOS physicists also didn’t measure the neutrinos at different distances from Fermilab, so Formaggio and colleagues couldn’t directly compare measurements made after different flight times. However, the rate at which neutrinos oscillate varies with their energy, with the clock ticking faster for more energetic neutrinos. So instead of looking for correlations between neutrinos measured at different times, Formaggio and colleagues looked for equivalent correlations in the number of muon neutrinos arriving in Minnesota with different energies.

    The researchers observed the strong correlations predicted by Leggett and Garg, as they report in a paper in press at Physical Review Letters. “As we expected, it’s a very obvious effect,” Formaggio says. The data underscore that the neutrino has no flavor until it’s actually measured, he says.

    The result is not surprising, Garg says, as neutrino oscillations are inherently quantum mechanical. Still, he says, it “probes the conflict between the quantum and classical worlds in a new regime.”

    Next would be to see whether neutrinos can test quantum mechanics in other ways, Formaggio and White say. Garg says he still hopes somebody will push the test he and Leggett devised as originally intended: to test whether realism holds for a truly macroscopic object. If it fails, our sense of reality really would go out the window.

    See the full article here .

    The American Association for the Advancement of Science is an international non-profit organization dedicated to advancing science for the benefit of all people.

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  • richardmitnick 7:58 pm on July 11, 2016 Permalink | Reply
    Tags: , Neutrinos, , ,   

    From New Scientist: “Neutrinos hint at why antimatter didn’t blow up the universe” 


    New Scientist

    4 July 2016
    Lisa Grossman

    Super-Kamiokande: a huge detector looking out for tiny particles. Kamioka Observatory/ICRR(Institute for Cosmic Ray Research)/The University of Tokyo

    It could all have been so different. When matter first formed in the universe, our current theories suggest that it should have been accompanied by an equal amount of antimatter – a conclusion we know must be wrong, because we wouldn’t be here if it were true. Now the latest results from a pair of experiments designed to study the behaviour of neutrinos – particles that barely interact with the rest of the universe – could mean we’re starting to understand why.

    Neutrinos and their antimatter counterparts, antineutrinos, each come in three types, or flavours: electron, muon and tau. Several experiments have found that neutrinos can spontaneously switch between these flavours, a phenomenon called oscillating.

    The T2K experiment in Japan watches for these oscillations as neutrinos travel between the J-PARC accelerator in Tokai and the Super-Kamiokande neutrino detector in Kamioka, 295 kilometres away.

    T2K map
    T2K map

    It began operating in February 2010, but had to shut down for several years after Japan was rocked by a magnitude-9 earthquake in 2011.

    Puff of radiation

    In 2013, the team announced that 28 of the muon neutrinos that took off from J-PARC had become electron neutrinos by the time they reached Super-Kamiokande, the first true confirmation that the metamorphosis was happening.

    They then ran the experiment with muon antineutrinos, to see if there was a difference between how the ordinary particles and their antimatter counterparts oscillate. An idea called charge-parity (CP) symmetry holds that these rates should be the same.

    CP symmetry is the notion that physics would remain basically unchanged if you replaced all particles with their respective antiparticles. It appears to hold true for nearly all particle interactions, and implies that the universe should have produced the same amount of matter and antimatter in the big bang.

    Matter and antimatter destroy one another, so if CP symmetry holds, both should have mostly vanished in a puff of radiation early on in the universe’s history, well before matter was able to congeal into solid stuff. That’s clearly not what happened, but we don’t know why. Any deviation from CP symmetry we observe could help explain this discrepancy.

    “We know in order to create more matter than antimatter in the universe, you need a process that violates CP symmetry,” says Patricia Vahle, who works on NoVA, a similar experiment to T2K that sends neutrinos between Illinois and Minnesota.

    FNAL/NOvA experiment
    FNAL/NOvA experiment

    “So we’re going out and looking for any process that can violate this CP symmetry.”

    Flavour changers

    We already know of one: the interactions of different kinds of quarks, the constituents of protons and neutrons in atoms. But their difference is not great enough to explain why matter dominated so completely in the modern universe. Neutrino oscillations are another promising place to look for deviations.

    This morning at the Neutrino conference in London, UK, we got our first signs of such deviations. Hirohisa Tanaka of the University of Toronto, Canada, reported the latest results from T2K. They have now seen 32 muon neutrinos morphing into the electron flavour, compared to just 4 muon antineutrinos becoming the anti-electron variety.

    This is more matter and less antimatter than they expected to see, assuming CP symmetry holds. Although the number of detections in each experiment is small, the difference is enough to rule out CP symmetry holding at the 2 sigma level – in other words, there is only around a 5 per cent chance that T2K would see such differences if CP symmetry is preserved in this process.

    Particle physicists normally wait until things reach the 3 sigma level before getting excited, and won’t consider it a discovery until 5 sigma, so it’s early days for neutrinos breaking CP symmetry. But at the same conference, Vahle presented the latest results from NoVA that revealed the two experiments were in broad agreement about the possibility.

    The extent of CP violation rests on a key parameter called delta-CP, which ranges from 0 to 2π. Both teams found that their results were best explained by setting the value equal to 1.5π. “Their data really does prefer the same value that T2K does,” says Asher Kaboth, who works on T2K. “All of the preferences for the delta-CP stuff are pointing in the same direction.”

    NoVA plans to run its own antineutrino experiments next year, which will help firm up the results, and both teams are continuing to gather more data. It’s too soon to say definitively, but one of the mysteries of why we are here could be on the road to getting solved

    See the full article here .

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  • richardmitnick 8:23 am on July 11, 2016 Permalink | Reply
    Tags: , Neutrinos, , , T2K presents first CP violation search result   

    From T2K: “T2K presents first CP violation search result” 

    T2K Experiment
    T2K Experiment, Japan


    July 4, 2016

    New data support growing hint of different oscillation probabilities for neutrinos and antineutrinos.

    The T2K Collaboration presented new results on neutrino and antineutrino oscillations at the 27th International Conference on Neutrino Physics and Astrophysics (Neutrino 2016) at Imperial College London. T2K’s new data continue to prefer maximal mixing in the atmospheric angle (θ23), a value of the CP violating phase (δCP) near the maximally violating value -π/2, and the normal ordering of the neutrino mass hierarchy.

    With nearly twice the antineutrino data in 2016 compared to their 2015 result, T2K has performed a new analysis of all data, as shown in Fig 1, fitting both neutrino and antineutrino modes simultaneously. If CP violation occurs in neutrinos, it will manifest itself as a difference in the oscillation probabilities of neutrinos and antineutrinos. T2K’s observed electron antineutrino appearance event rate is lower than would be expected based on the electron neutrino appearance event rate, assuming that CP symmetry is conserved.

    When analyzed in a full framework of three neutrino and antineutrino flavors, and combined with measurements of electron antineutrino disappearance from reactor experiments, the size of the expected T2K 90% confidence interval for δCP with the current statistics ranges from approximately 2π (ie. the full range of δCP) to 1π depending on the true value of δCP and the true mass ordering. The actual T2K data yield a 90% confidence interval for δCP of [–3.02; –0.49] ([–1.87 ; –0.98]) for the normal (inverted) mass ordering, as shown in Fig 2. The CP conserving values (δCP=0 and δCP= π) lie outside of this interval.

    This new result is based on a data set of 1.44×1021 protons on target (POT), which is 20% of the POT exposure that T2K is set to receive. The full T2K exposure of 7.8×1021 POT is expected to come by ~2021, thanks to planned upgrades to the J-PARC Main Ring accelerator and the neutrino beamline. Moreover, T2K is proposing a run extension that will lead to a full exposure of 20×1021 POT, with 3σ sensitivity to CPV observation, by ~2025, when the next generation experiments are expected to begin operations.

    Violation of CP symmetry could hold the key to one of the most profound questions in science, which is: why is the universe comprised of matter today even though the Big Bang produced equal parts matter and antimatter? Although the new T2K result is not yet statistically significant, it is nevertheless an intriguing hint that the neutrino will continue to provide new breakthroughs in our understanding of the universe.

    More details on the new T2K result, as well as prospects for future running of the experiment, can be found in the presentation file from the London Neutrino 2016 conference.

    Figure 1. Neutrino(top) and antineutrino(bottom) event distributions at the T2K far detector (Super-K), for both muon (left) and electron (right) flavors. In each figure, the black points show T2K (anti)neutrino data, the black curves show the expectations for the case of no neutrino oscillation, and the blue curves show the expectation for the best fit oscillation parameter values.

    Figure 2. Negative log likelihood values as a function of the CP violating phase parameter δCP; The black (red) curves show the case for the normal (inverted) mass ordering; the black (red) vertical lines with hatch marks show the 90% CL allowed regions for the normal (inverted) mass ordering. This figure shows the result for T2K neutrino and antineutrino data, combined with reactor antineutrino results. The CP conserving values (δCP =0 and δCP= π) lie outside the 90% region.

    See the full article here .

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    T2K map
    T2K map

    T2K (Tokai to Kamioka) is a long-baseline neutrino experiment in Japan, and is studying neutrino oscillations. Neutrinos are elementary particles which come in three “flavours”: electron, muon, and tau. They only interact through the weak force, and are very difficult to detect as they rarely interact with matter. Electron neutrinos are produced in large numbers in the Sun, and solar neutrinos can pass all the way through the Earth without interacting.

    T2K has made a search for oscillations from muon neutrinos to electron neutrinos, and announced the first experimental indications for them in June 2011. These oscillations had never been observed by any previous experiment. T2K is also making measurements of oscillations from muon neutrinos to tau neutrinos (which have been seen by previous experiments). It will make the most accurate measurements to date of the probability of these oscillations and of the difference between the masses of two of the neutrinos (to be precise, T2K measures the difference between the squares of these masses).

  • richardmitnick 5:02 pm on July 1, 2016 Permalink | Reply
    Tags: , , Neutrinos   

    From FNAL: “Getting a feel (and a taste) for neutrinos” 

    FNAL II photo

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    July 1, 2016
    David Coplowe

    These plots show how four different kinds of antineutrino interactions show up in different ways when you look at these interactions in more than one dimension.

    If you thought finding Nemo was hard, think again. Imagine a trillion (that’s one followed by 12 zeros) little Nemos traveling through your body each second without you even noticing them. Give it a day, a month, or even a year, and you wouldn’t catch one. This is happening to you right now with neutrinos, coming from the sun. Even though they are everywhere, they rarely interact with anything due to their tiny mass and lack of charge.

    Physicists to the rescue! Fortunately, there is a way to overcome neutrinos’ elusiveness by creating intense neutrino beams and building large dense detectors, like MINERvA, made of heavy atoms packed with protons and neutrons.

    Great! Now we are ready to make measurements of how neutrinos interact, right? But it’s not quite that easy. For one, we can detect neutrinos only indirectly, through some telltale signature of their presence. And then there are the fakers: Having these big atomic nuclei poses complicated issues, as several different effects come into play. Some of these effects can mimic what the experimenter is actually looking for. Physicists therefore need to take great care in understanding what fakes their signal and to constrain it so that they can precisely measure their interaction of interest.

    Cheryl Patrick, formerly of Northwestern University (now at University College London), presented these results at the Fermilab Joint Experimental-Theoretical Physics Seminar on June 17.

    Cheryl Patrick and the MINERvA collaboration did just this, taking it one step further with a double differential cross section. At the June 17 Wine and Cheese Seminar, Cheryl presented results on the latest antineutrino measurement at MINERvA.


    By searching for events with a single antimuon, any number of neutrons and only low-energy protons, she was able to look for a particular type of action that experimenters are interested in and present how various models compared with data in two dimensions.

    Why are two dimensions better than one? Think of being in a restaurant and finishing your meal with a coffee. You love the flavor but want to make it a little more sweet. On your table are two identical pots that look like sugar, but while one contains sugar, the other has salt. You don’t want to spoil your coffee by adding the wrong white powder, but the test using just your eyes is not enough to tell them apart. To get a definitive answer, you can use your tongue to taste which is right. This is how we use multiple dimensions to add information and better understand what’s happening. In neutrino physics these dimensions can be different aspects of the final particles that we can measure in our detector.

    The work reported by Cheryl Patrick looked at variables in two dimensions to not only isolate signal events from those faking it, but also to enable a better understanding of how these results compare to theoretical models of the nucleus. These models will then be used as early as when NOvA starts looking at antineutrino interactions this month.

    FNAL NOvA experiment
    FNAL NOvA experiment

    See the full article here .

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    Fermilab Campus

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.

  • richardmitnick 6:32 am on June 25, 2016 Permalink | Reply
    Tags: , KM3NeT collaboration, Neutrinos   

    From phys.org: “KM3NeT unveils detailed plans for largest neutrino telescope in the world” 


    June 24, 2016
    No writer credit found


    Images credit: http://www3.imperial.ac.uk/newseventsimages?p_image_type=mainnews2012&p_image_id=18164

    Artist’s rendering of the KM3NeT array. Credit: Marco Kraan/Property KM3NeT Consortium

    KM3NeT – a European collaboration pioneering the deployment of kilometre cubed arrays of neutrino detectors off the Mediterranean coast – has reported in detail on the scientific aims, technology and costs of its proposal in the Journal of Physics G: Nuclear and Particle Physics.

    Neutrinos are ideal messengers from the cosmos. These stable, sub-atomic particles can travel long distances without being disturbed by matter or magnetic fields in their path. Their detection is prized by astronomers as neutrino-emitting sources such as the remnants of Super Nova explosions provide important clues to the evolution of our universe. The study of neutrinos could also help in expanding our knowledge of atomic physics. However, there is a catch.

    “The weak interaction between neutrinos and normal matter is a blessing and curse,” commented Maarten de Jong, who has been involved in the KM3NeT project since the first design study in 2006 and is spokesperson for the collaboration. “It makes detecting them notoriously difficult, which is why you need a giant detector.”

    It’s a big undertaking. To detect neutrinos from the cosmos you need a massive site, which can then be used as a converter target as follows –

    Firstly, a neutrino interacts with an atomic nucleus in the target medium to produce relativistic charged particles. Secondly, the passage of these relativistic charged particles through the medium produces so-called Cherenkov light (the typical blue light on pictures of nuclear reactors). And lastly, the Cherenkov light is detected by a 3-dimensional spatial array of incredibly sensitive photo-sensors.

    Fortunately, Mother Earth is able to lend a helping hand in bringing down the cost of developing such a huge structure. “It turns out that the deep waters in the Mediterranean are ideal,” explained de Jong. “These natural waters come for free, are very transparent to the Cherenkov light, and sufficiently accessible to allow the deployment of strings of photo-sensors.”

    At a depth of several kilometres there is no more daylight, which means that KM3NeT’s optical modules can be placed in darkness for maximum sensitivity to the neutrino-signalling Cherenkov light. Also, under these conditions the neutrino telescope can be operated 24 hours a day, 7 days a week.

    The KM3NeT collaboration has developed what it believes is a cost-effective plan for building out this research infrastructure at the bottom of the sea. The phased rolled-out will consist of three so-called building blocks, where each building block comprises 115 strings of 18 optical modules (glass spheres containing 31 outward-facing photomultiplier tubes).

    The strings, which can extend for several hundred metres, are anchored on the seabed and kept vertical by the buoyancy of the optical modules and the use of an additional buoy at the very top. These long chains of detectors are important, because they allow the scientists to reconstruct the trajectory of the incoming neutrinos. This data can then be used by researchers to identify the locations of the corresponding sources in outer space.

    The array will provide a large piece of the puzzle required to monitor the whole of the sky for incoming neutrinos, linking existing telescopes based under the South Pole (IceCube) and in Lake Baikal, Russia (Gigaton Volume Detector – GVD).

    U Wisconsin ICECUBE neutrino detector at the South Pole
    IceCube neutrino detector interior
    U Wisconsin ICECUBE neutrino detector at the South Pole

    GVD – no images made available

    In December 2015, the KM3NeT collaboration successful tested the deployment of a string of its latest optical modules. It has already raised EURO 31 million to begin phase one of the project. The work builds on experience gained through ANTARES (a 12 string array based off the coast of France).

    More information: Journal of Physics G: Nuclear and Particle Physics. DOI: 10.1088/0954-3899/43/8/084001

    Map of the various preparation, integration and installation sites at the time of this writing. (24 June 2016)

    Science team:
    S Adrián-Martínez1, M Ageron2, F Aharonian3, S Aiello4, A Albert5, F Ameli6, E Anassontzis7, M Andre8, G Androulakis9, M Anghinolfi10, G Anton11, M Ardid1, T Avgitas12, G Barbarino13,14, E Barbarito15, B Baret12, J Barrios-Martí16, B Belhorma17, A Belias9, E Berbee18, A van den Berg19, V Bertin2, S Beurthey2, V van Beveren18, N Beverini20,21, S Biagi22, A Biagioni6, M Billault2, M Bondì4, R Bormuth18,23, B Bouhadef21, G Bourlis24, S Bourret12, C Boutonnet12, M Bouwhuis18, C Bozza25, R Bruijn26, J Brunner2, E Buis27, J Busto2, G Cacopardo22, L Caillat2, M Calamai21, D Calvo16, A Capone6,28, L Caramete29, S Cecchini30, S Celli6,28,31, C Champion12, R Cherkaoui El Moursli32, S Cherubini22,33, T Chiarusi30, M Circella15, L Classen11, R Cocimano22, J A B Coelho12, A Coleiro12, S Colonges12, R Coniglione22, M Cordelli34, A Cosquer2, P Coyle2, A Creusot12, G Cuttone22, A D’Amico18, G De Bonis6, G De Rosa13,14, C De Sio25, F Di Capua13, I Di Palma6,28, A F Díaz García35, C Distefano22, C Donzaud12, D Dornic2, Q Dorosti-Hasankiadeh19, E Drakopoulou9, D Drouhin5, L Drury3, M Durocher22,31, T Eberl11, S Eichie11,36, D van Eijk18, I El Bojaddaini37, N El Khayati32, D Elsaesser38, A Enzenhöfer2, F Fassi32, P Favali39, P Fermani6, G Ferrara22,33, C Filippidis9, G Frascadore22, L A Fusco30,40, T Gal11, S Galatà12, F Garufi13,14, P Gay12,41, M Gebyehu18, V Giordano4, N Gizani24, R Gracia12, K Graf11, T Grégoire12, G Grella25, R Habel34, S Hallmann11, H van Haren42, S Harissopulos9, T Heid11, A Heijboer18, E Heine18, S Henry2, J J Hernández-Rey16, M Hevinga19, J Hofestädt11, C M F Hugon10, G Illuminati16, C W James11, P Jansweijer18, M Jongen18, M de Jong18, M Kadler38, O Kalekin11, A Kappes11, U F Katz11, P Keller2, G Kieft18, D Kießling11, E N Koffeman18, P Kooijman26,43, A Kouchner12, V Kulikovskiy22, R Lahmann11, P Lamare2, A Leisos24, E Leonora4, M Lindsey Clark12, A Liolios44, C D Llorens Alvarez1, D Lo Presti4, H Löhner19, A Lonardo6, M Lotze16, S Loucatos12, E Maccioni20,21, K Mannheim38, A Margiotta30,40, A Marinelli20,21, O Mariş29, C Markou9, J A Martínez-Mora1, A Martini34, R Mele13,14, K W Melis18, T Michael18, P Migliozzi13, E Migneco22, P Mijakowski45, A Miraglia22, C M Mollo13, M Mongelli15, M Morganti21,46, A Moussa37, P Musico10, M Musumeci22, S Navas35, C A Nicolau6, I Olcina16, C Olivetto12, A Orlando22, A Papaikonomou24, R Papaleo22, G E Păvălaş29, H Peek18, C Pellegrino30,40, C Perrina6,28, M Pfutzner18, P Piattelli22, K Pikounis9, G E Poma22,33, V Popa29, T Pradier47, F Pratolongo10, G Pühlhofer48, S Pulvirenti22, L Quinn2, C Racca5, F Raffaelli21, N Randazzo4, P Rapidis9, P Razis49, D Real16, L Resvanis7, J Reubelt11, G Riccobene22, C Rossi10, A Rovelli22, M Saldaña1, I Salvadori2, D F E Samtleben18,23, A Sánchez García16, A Sánchez Losa15, M Sanguineti10, A Santangelo48, D Santonocito22, P Sapienza22, F Schimmel18, J Schmelling18, V Sciacca22, M Sedita22, T Seitz11, I Sgura15, F Simeone6, I Siotis9, V Sipala4, B Spisso13, M Spurio30,40, G Stavropoulos9, J Steijger18, S M Stellacci25, D Stransky11, M Taiuti10,50, Y Tayalati37,32, D Tézier2, S Theraube2, L Thompson51, P Timmer18, C Tönnis16, L Trasatti34, A Trovato22, A Tsirigotis24, S Tzamarias24, E Tzamariudaki9, B Vallage12, V Van Elewyck12, J Vermeulen18, P Vicini6, S Viola22, D Vivolo13,14, M Volkert11, G Voulgaris7, L Wiggers18, J Wilms36, E de Wolf18,26, K Zachariadou52, J D Zornoza16 and J Zúñiga16

    Author affiliations

    1 Universitat Politècnica de València, Instituto de Investigación para la Gestión Integrada de las Zonas Costeras, C/ Paranimf, 1, Gandia, E-46730, Spain

    2 Aix-Marseille Université, CNRS/IN2P3, CPPM UMR 7346, F-13288, Marseille, France

    3 The Dublin Institute for Advanced Studies, 10 Burlington Road, Dublin 4, Ireland

    4 INFN, Sezione di Catania, Via Santa Sofia 64, Catania, I-95123, Italy

    5 Université de Strasbourg, Université de Haute Alsace, GRPHE, 34, Rue du Grillenbreit, Colmar, F-68008, France

    6 INFN, Sezione di Roma, Piazzale Aldo Moro 2, Roma, I-00185, Italy

    7 Physics Department, N. and K. University of Athens, Athens, Greece

    8 Universitat Politècnica de Catalunya, Laboratori d’Aplicacions Bioacústiques, Centre Tecnològic de Vilanova i la Geltrú, Avda. Rambla Exposició, s/n, Vilanova i la Geltrú, E-08800, Spain

    9 NCSR Demokritos, Institute of Nuclear and Particle Physics, Ag. Paraskevi Attikis, Athens, 15310, Greece

    10 INFN, Sezione di Genova, Via Dodecaneso 33, Genova, I-16146, Italy

    11 Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Straße 1, D-91058 Erlangen, Germany

    12 APC, Université Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cité, F-75205 Paris, France

    13 INFN, Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Via Cintia ed. G, Napoli, I-80126, Italy

    14 University of Napoli, Dip. Scienze fisiche, Complesso Universitario di Monte S. Angelo, Via Cintia ed. G, Napoli, I-80126, Italy

    15 INFN, Sezione di Bari, Via Amendola 173, Bari, I-70126, Italy

    16 IFIC—Instituto de Física Corpuscular (CSIC—Universitat de València), c/Catedrático José Beltrán, 2, E-46980 Paterna, Valencia, Spain

    17 National Center for Energy Sciences and Nuclear Techniques, B.P. 1382, R.P. 10001 Rabat, Morocco

    18 FOM, Nikhef, PO Box 41882, Amsterdam, 1098 DB, The Netherlands

    19 KVI-CART University of Groningen, Groningen, The Netherlands

    20 Università di Pisa, Dipartimento di Fisica, Largo Bruno Pontecorvo 3, Pisa, I-56127, Italy

    21 INFN, Sezione di Pisa, Largo Bruno Pontecorvo 3, Pisa, I-56127, Italy

    22 INFN, Laboratori Nazionali del Sud, Via S. Sofia 62, Catania, I-95123, Italy

    23 Leiden University, Leiden Institute of Physics, PO Box 9504, Leiden, 2300 RA, The Netherlands

    24 Hellenic Open University, School of Science / Technology, Natural Sciences, Sahtouri St. / Ag. Andreou St. 16, Patra, 26222, Greece

    25 University of Salerno, Department of Physics, Via Giovanni Paolo II 132, Fisciano, I-84084, Italy

    26 University of Amsterdam, Institute of Physics/IHEF, PO Box 94216, Amsterdam, 1090 GE, The Netherlands

    27 TNO, Technical Sciences, PO Box 155, Delft, 2600 AD, The Netherlands

    28 Università La Sapienza, Dipartimento di Fisica, Piazzale Aldo Moro 2, Roma, I-00185, Italy

    29 ISS, 242, Vacaresti, Bucharest, 40061, Romania

    30 INFN, Sezione di Bologna, v.le C. Berti-Pichat, 6/2, Bologna, I-40127, Italy

    31 Gran Sasso Science Institute, GSSI, Viale Francesco Crispi 7, L’Aquila, I-67100, Italy

    32 University Mohammed V in Rabat, Faculty of Sciences, 4 av. Ibn Battouta, B.P. 1014, R.P. 10000 Rabat, Morocco

    33 University of Catania, Dipartimento di Fisica ed Astronomia di Catania, Via Santa Sofia 64, Catania, I-95123, Italy

    34 INFN, LNF, Via Enrico Fermi , 40, Frascati, I-00044, Italy

    35 Universidad de Granada & C.A.F.P.E, Av. del Hospicio s/n, E-18071 Granada, Spain

    36 Friedrich-Alexander-Universität Erlangen-Nürnberg, Remeis Sternwarte, Sternwartstraße 7, D-96049 Bamberg, Germany

    37 University Mohammed I, Faculty of Sciences, BV Mohammed VI, B.P. 717, R.P. 60000 Oujda, Morocco

    38 University Würzburg, Emil-Fischer-Straße 31, D-97074 Würzburg, Germany

    39 INGV, Via di Vigna Murata, 605, Rome, I-00143, Italy

    40 University of Bologna, Dipartimento di Fisica e Astronomia, v.le C. Berti-Pichat, 6/2, Bologna, I-40127, Italy

    41 IN2P3, LPC, Campus des Cézeaux 24, avenue des Landais BP 80026, Aubière Cedex, F-63171, France

    42 NIOZ, PO Box 59, Den Burg, Texel, 1790 AB, The Netherlands

    43 Utrecht University, Department of Physics and Astronomy, PO Box 80000, Utrecht, 3508 TA, The Netherlands

    44 Aristotle University Thessaloniki, University Campus, Thessaloniki, 54124, Greece

    45 National Centre for Nuclear Research, 00-681 Warsaw, Poland

    46 Accademia Navale di Livorno, Viale Italia 72, Livorno, I-57100, Italy

    47 IN2P3, IPHC, 23 rue du Loess, Strasbourg, F-67037, France

    48 Eberhard Karls Universität Tübingen, Institut für Astronomie und Astrophysik, Sand 1, D-72076 Tübingen, Germany

    49 University of Cyprus, Physics, Kallipoleos 75, Nicosia, 1678, Cyprus

    50 University of Genova, Via Dodecaneso 33, Genova, I-16146, Italy

    51 University of Sheffield, Department of Physics and Astronomy, Hounsfield Road, Sheffield, S3 7RH, UK

    52 Technological Education Institute of Pireaus, Thivon and P. Ralli Str. 250, Egaleo—Athens, 12244, Greece

    See the full article here .

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    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

  • richardmitnick 4:24 pm on June 21, 2016 Permalink | Reply
    Tags: , , Neutrinos, ,   

    From Rapid City Journal via SURF: “DUNE will be SD’s largest project ever” 

    SURF logo
    Sanford Underground levels

    Sanford Underground Research facility

    Rapid City Journal

    Jun 13, 2015
    Tom Griffith Journal staff


    Hundreds of scientists from around the world are patiently awaiting the start of a billion-dollar experiment that, in a scene straight out of a science fiction movie, will fire a beam of tiny neutrinos from a laboratory near Chicago that will carry the subatomic particles a mile underground and 800 miles away in the Black Hills of South Dakota.

    By itself, the $300 million investment for the experiment at the Sanford Lab in Lead represents the largest single project in the history of South Dakota. And, project advocates say the experiment has the potential to advance scientific knowledge and yield technological advancements on a par with the race to the moon in the 1960s.

    “The people I interact with refer to this as one of the most significant particle-physics experiments that has or likely will ever occur on U.S. soil,” said Mike Headley, executive director of the South Dakota Science & Technology Authority, which manages the Sanford Underground Research Facility. “No one I know can remember a project of this scale that has been executed in this state.”

    At its core, the Long-Baseline Neutrino Facility (LBNF) and the associated Deep Underground Neutrino Experiment (DUNE), will send a beam of neutrinos through the earth from Fermi National Accelerator Laboratory near Batavia, Ill., to the Sanford Lab in western South Dakota, according to the U.S. Department of Energy.

    Having very little mass and no electric charge, neutrinos pass through ordinary matter nearly undisturbed — they can pass through 100 million miles of lead without stopping — and they continuously pass through the earth and our bodies, scientists say.

    In Illinois, project leaders plan to build four structures on the Fermilab site. One building would be connected via a vertical shaft to an underground hall about 200 feet below the Fermilab. The project also would include the construction of a 50- to 60-foot-high hill on the Fermi site as part of the facility that would create the neutrinos, according to the DOE.

    In South Dakota, project leaders plan to construct one building at the surface adjacent to an existing building near the Ross Shaft. About one mile underground, the project would include three large caverns, each about 60 feet wide and 500 feet long. These caverns would provide space for utilities and four large detectors filled with liquid argon to detect the neutrinos fired from Fermi, Headley explained.

    Particle detectors at Sanford Lab would record neutrinos from the Fermilab and measure their properties. They also would look for neutrinos from a supernova and search for signs of nucleon decay. With the data, scientists aim to learn more about the building blocks of matter and determine the exact role that neutrinos play in the universe, he said.

    “I’m a South Dakota kid, from Brookings originally, so to have an opportunity to be part of an international team doing this in my home state is really amazing,” Headley said. “It’s really cool.”

    Michael Weis, Fermi site office manager for the DOE, said on Friday that the DUNE international collaboration includes 776 scientists from 144 institutions and 26 nations, and it is still growing.

    “The number of partners in this project is not unprecedented as high-energy physics experiments have historically involved large collaborations, most recently with the Large Hadron Collider experiments at the CERN laboratory in Europe,” Weis said. “The significance here is that a large number of scientists in the international community want to build and conduct an experiment at a facility here in the United States. This means that the U.S. has an opportunity to host a world-class science facility of this scale, and an international `megascience project’ for the first time.”

    Years in the making, scientists behind the project have exhibited remarkable patience in its development, and must remain patient to realize the potential of the experiment. According to Weis, the preliminary schedule estimates facility construction could start at the Sanford Lab as early as 2017, and be completed in the mid-2020s. Installation of the experiment into the facility could begin as early as 2021 and continue for a few years beyond this, he said, while the experiment duration is estimated to be 20 years. LBNF/DUNE is being funded by the DOE, as well as the international cast of collaborators.

    Headley said the significance of the experiment to the scientific community, the State of South Dakota, and the nation, could not be understated.

    Last year, an important DOE scientific review panel called the “Particle Physics Project Prioritization Panel,” or P5, identified the experiment as a top priority for U.S. particle physics, recommending it be planned as an international effort in order to achieve the greatest scientific capability, Headley explained. DUNE represents the convergence of several formerly independent worldwide efforts around the opportunity provided by a new neutrino beam facility planned at the Fermilab and by the new and significant expansion at Sanford Lab, he said.

    “If you look at all the effort and research and development that allowed us to go to the moon, these are the type of technologies that have the potential to power our economy and make us globally competitive into the future,” Headley said. “In terms of science, this experiment is on the level of the Higgs Boson. The answers to some of the questions this experiment will address will be competitive for a Nobel Prize.”

    And yet, Headley acknowledged, “It’s going to lead to more questions, some of which we haven’t yet thought of.”

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    About us.
    The Sanford Underground Research Facility in Lead, South Dakota, advances our understanding of the universe by providing laboratory space deep underground, where sensitive physics experiments can be shielded from cosmic radiation. Researchers at the Sanford Lab explore some of the most challenging questions facing 21st century physics, such as the origin of matter, the nature of dark matter and the properties of neutrinos. The facility also hosts experiments in other disciplines—including geology, biology and engineering.

    The Sanford Lab is located at the former Homestake gold mine, which was a physics landmark long before being converted into a dedicated science facility. Nuclear chemist Ray Davis earned a share of the Nobel Prize for Physics in 2002 for a solar neutrino experiment he installed 4,850 feet underground in the mine.

    Homestake closed in 2003, but the company donated the property to South Dakota in 2006 for use as an underground laboratory. That same year, philanthropist T. Denny Sanford donated $70 million to the project. The South Dakota Legislature also created the South Dakota Science and Technology Authority to operate the lab. The state Legislature has committed more than $40 million in state funds to the project, and South Dakota also obtained a $10 million Community Development Block Grant to help rehabilitate the facility.

    In 2007, after the National Science Foundation named Homestake as the preferred site for a proposed national Deep Underground Science and Engineering Laboratory (DUSEL), the South Dakota Science and Technology Authority (SDSTA) began reopening the former gold mine.

    In December 2010, the National Science Board decided not to fund further design of DUSEL. However, in 2011 the Department of Energy, through the Lawrence Berkeley National Laboratory, agreed to support ongoing science operations at Sanford Lab, while investigating how to use the underground research facility for other longer-term experiments. The SDSTA, which owns Sanford Lab, continues to operate the facility under that agreement with Berkeley Lab.

    The first two major physics experiments at the Sanford Lab are 4,850 feet underground in an area called the Davis Campus, named for the late Ray Davis. The Large Underground Xenon (LUX) experiment is housed in the same cavern excavated for Ray Davis’s experiment in the 1960s.
    LUX/Dark matter experiment at SURFLUX/Dark matter experiment at SURF

    In October 2013, after an initial run of 80 days, LUX was determined to be the most sensitive detector yet to search for dark matter—a mysterious, yet-to-be-detected substance thought to be the most prevalent matter in the universe. The Majorana Demonstrator experiment, also on the 4850 Level, is searching for a rare phenomenon called “neutrinoless double-beta decay” that could reveal whether subatomic particles called neutrinos can be their own antiparticle. Detection of neutrinoless double-beta decay could help determine why matter prevailed over antimatter. The Majorana Demonstrator experiment is adjacent to the original Davis cavern.

    Another major experiment, the Long Baseline Neutrino Experiment (LBNE)—a collaboration with Fermi National Accelerator Laboratory (Fermilab) and Sanford Lab, is in the preliminary design stages. The project got a major boost last year when Congress approved and the president signed an Omnibus Appropriations bill that will fund LBNE operations through FY 2014. Called the “next frontier of particle physics,” LBNE will follow neutrinos as they travel 800 miles through the earth, from FermiLab in Batavia, Ill., to Sanford Lab.

    Fermilab LBNE

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