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  • richardmitnick 8:35 am on March 15, 2019 Permalink | Reply
    Tags: "How Much Of The Dark Matter Could Neutrinos Be?", , , , , , , Neutrinos, Neutrinos are the only Standard Model particles that behave like dark matter should. But they can’t be the full story   

    From Ethan Siegel: “How Much Of The Dark Matter Could Neutrinos Be?” 

    From Ethan Siegel
    Mar 14, 2019

    They’re the only Standard Model particles that behave like dark matter should. But they can’t be the full story.

    1
    While the web of dark matter (purple) might seem to determine cosmic structure formation on its own, the feedback from normal matter (red) can severely impact galactic scales. Both dark matter and normal matter, in the right ratios, are required to explain the Universe as we observe it. Neutrinos are ubiquitous, but standard, light neutrinos cannot account for most (or even a significant fraction) of the dark matter. (ILLUSTRIS COLLABORATION / ILLUSTRIS SIMULATION)

    All throughout the Universe, there’s more than what we’re capable of seeing. When we look out at the stars moving around within galaxies, the galaxies moving withing groups and clusters, or the largest structures of all that make up the cosmic web, everything tells the same disconcerting story: we don’t see enough matter to explain the gravitational effects that occur. In addition to the stars, gas, plasma, dust, black holes and more, there must be something else in there causing an additional gravitational effect.

    Traditionally, we’ve called this dark matter, and we absolutely require it to explain the full suite of observations throughout the Universe. While it cannot be made up of normal matter — things made of protons, neutrons, and electrons — we do have a known particle that could have the right behavior: neutrinos. Let’s find out how much of the dark matter neutrinos could possibly be.

    2
    The neutrino was first proposed in 1930, but was not detected until 1956, from nuclear reactors. In the years and decades since, we’ve detected neutrinos from the Sun, from cosmic rays, and even from supernovae. Here, we see the construction of the tank used in the solar neutrino experiment in the Homestake gold mine from the 1960s.(BROOKHAVEN NATIONAL LABORATORY)

    At first glance, neutrinos are the perfect dark matter candidate. They barely interact at all with normal matter, and neither absorb nor emit light, meaning that they won’t generate an observable signal capable of being picked up by telescopes. At the same time, because they interact through the weak force, it’s inevitable that the Universe created enormous numbers of them in the extremely early, hot stages of the Big Bang.

    We know that there are leftover photons from the Big Bang, and very recently we’ve also detected indirect evidence that there are leftover neutrinos as well. Unlike the photons, which are massless, it’s possible that neutrinos have a non-zero mass. If they have the right value for their mass based on the total number of neutrinos (and antineutrinos) that exist, they could conceivably account for 100% of the dark matter.

    3
    The largest-scale observations in the Universe, from the cosmic microwave background [CMB]to the cosmic web to galaxy clusters to individual galaxies, all require dark matter to explain what we observe. The large-scale structure requires it, but the seeds of that structure, from the Cosmic Microwave Background, require it too. (CHRIS BLAKE AND SAM MOORFIELD)

    CMB per ESA/Planck


    ESA/Planck 2009 to 2013

    So how many neutrinos are there? That depends on the number of types (or species) of neutrino.

    Although we can detect neutrinos directly using enormous tanks of material designed to capture their rare interactions with matter, this is both incredibly inefficient and is only going to capture a tiny fraction of them. We can see neutrinos that are the result of particle accelerators, nuclear reactors, fusion reactions in the Sun, and cosmic rays interacting with our planet and atmosphere. We can measure their properties, including how they transform into one another, but not the total number of types of neutrino.

    4
    In this illustration, a neutrino has interacted with a molecule of ice, producing a secondary particle — a muon — that moves at relativistic speed in the ice, leaving a trace of blue light behind it. Directly detecting neutrinos has been a herculean but successful effort, and we are still trying to puzzle out the full suite of their nature. (NICOLLE R. FULLER/NSF/ICECUBE)

    U Wisconsin ICECUBE neutrino detector at the South Pole


    But there is a way to make the critical measurement from particle physics, and it comes from a rather unexpected place: the decay of the Z-boson. The Z-boson is the neutral boson that mediates the weak interaction, enabling certain types of weak decays. The Z couples to both quarks and leptons, and whenever you produce one in a collider experiment, there’s a chance that it will simply decay into two neutrinos.

    Those neutrinos are going to be invisible! We cannot typically detect the neutrinos we create from particle decays in colliders, as it would take a detector with the density of a neutron star to capture them. But by measuring what percentage of the decays produce “invisible” signals, we can infer how many types of light neutrino (whose mass is less than half the Z-boson mass) there are. It’s a spectacular and unambiguous result known for decades now: there are three.

    Standard Model of Particle Physics (LATHAM BOYLE AND MARDUS OF WIKIMEDIA COMMONS)


    This diagram displays the structure of the Standard Model, illustrating the key relationships and patterns. In particular, this diagram depicts all of the particles in the Standard Model, the role of the Higgs boson, and the structure of electroweak symmetry breaking, indicating how the Higgs vacuum expectation value breaks electroweak symmetry, and how the properties of the remaining particles change as a consequence. Note that the Z-boson couples to both quarks and leptons, and can decay through neutrino channels. (LATHAM BOYLE AND MARDUS OF WIKIMEDIA COMMONS)

    Coming back to dark matter, we can calculate, based on all the different signals we see, how much extra dark matter is necessary to give us the right amount of gravitation. In every way we know how to look, including:

    from colliding galaxy clusters,
    from galaxies moving within X-ray emitting clusters,
    from the fluctuations in the cosmic microwave background,
    from the patterns found in the large-scale structure of the Universe,
    and from the internal motions of stars and gas within individual galaxies,

    we find that we require about five times the abundance of normal matter to exist in the form of dark matter. It’s a great success of dark matter for modern cosmology that just by adding one ingredient to solve one puzzle, a whole slew of other observational puzzles are also solved.

    5
    Four colliding galaxy clusters, showing the separation between X-rays (pink) and gravitation (blue), indicative of dark matter. On large scales, cold dark matter is necessary, and no alternative or substitute will do.(X-RAY: NASA/CXC/UVIC./A.MAHDAVI ET AL. OPTICAL/LENSING: CFHT/UVIC./A. MAHDAVI ET AL. (TOP LEFT); X-RAY: NASA/CXC/UCDAVIS/W.DAWSON ET AL.; OPTICAL: NASA/ STSCI/UCDAVIS/ W.DAWSON ET AL. (TOP RIGHT); ESA/XMM-NEWTON/F. GASTALDELLO (INAF/ IASF, MILANO, ITALY)/CFHTLS (BOTTOM LEFT); X-RAY: NASA, ESA, CXC, M. BRADAC (UNIVERSITY OF CALIFORNIA, SANTA BARBARA), AND S. ALLEN (STANFORD UNIVERSITY) (BOTTOM RIGHT))

    NASA/Chandra X-ray Telescope



    CFHT Telescope, Maunakea, Hawaii, USA, at Maunakea, Hawaii, USA,4,207 m (13,802 ft) above sea level

    NASA/ESA Hubble Telescope

    ESA/XMM Newton

    If you have three species of light neutrino, it would only take a relatively small amount of mass to account for all the dark matter: a few electron-Volts (about 3 or 4 eV) per neutrino would do it. The lightest particle found in the Standard Model besides the neutrino is the electron, and that has a mass of about 511 keV, or hundreds of thousands of times the neutrino mass we want.

    Unfortunately, there are two big problems with having light neutrinos that are that massive. When we look in detail, the idea of massive neutrinos is insufficient to make up 100% of the dark matter.

    6
    A distant quasar will have a big bump (at right) coming from the Lyman-series transition in its hydrogen atoms. To the left, a series of lines known as a forest appears. These dips are due to the absorption of intervening gas clouds, and the fact that the dips have the strengths they do place constraints on the temperature of dark matter. It cannot be hot. (M. RAUCH, ARAA V. 36, 1, 267 (1998))

    The first problem is that neutrinos, if they are the dark matter, would be a form of hot dark matter. You might have heard the phrase “cold dark matter” before, and what it means is that the dark matter must be moving slowly compared to the speed of light at early times.

    Why?

    If dark matter were hot, and moving quickly, it would prevent the gravitational growth of small-scale structure by easily streaming out of it. The fact that we form stars, galaxies, and clusters of galaxies so early rules this out. The fact that we see the weak lensing signals we do rules this out. The fact that we see the pattern of fluctuations in the cosmic microwave background rules this out. And direct measurements of clouds of gas in the early Universe, through a technique known as the Lyman-α forest, definitively rule this out. Dark matter cannot be hot.

    7
    The dark matter structures which form in the Universe (left) and the visible galactic structures that result (right) are shown from top-down in a cold, warm, and hot dark matter Universe. From the observations we have, at least 98%+ of the dark matter must be cold. (ITP, UNIVERSITY OF ZURICH)

    A number of collaborations have measured the oscillations of one species of neutrinos to another, and this enables us to infer the mass differences between the different types. Since the 1990s, we’ve been able to infer that the mass difference between two of the species are on the order of about 0.05 eV, and the mass difference between a different two species is approximately 0.009 eV. Direct constraints on the mass of the electron neutrino come from tritium decay experiments, and show that the electron neutrino must be less massive than about 2 eV.

    8
    A neutrino event, identifiable by the rings of Cerenkov radiation that show up along the photomultiplier tubes lining the detector walls, showcase the successful methodology of neutrino astronomy. This image shows multiple events, and is part of the suite of experiments paving our way to a greater understanding of neutrinos. (SUPER KAMIOKANDE COLLABORATION)

    Super-Kamiokande experiment. located under Mount Ikeno near the city of Hida, Gifu Prefecture, Japan

    Beyond that, the cosmic microwave background [CMB [above] (from Planck [above]) and the large-scale structure data (from the Sloan Digital Sky Survey) tells us that the sum of all the neutrino masses is at most approximately 0.1 eV, as too much hot dark matter would definitively affect these signals. From the best data we have, it appears that the mass values that the known neutrinos have are very close to the lowest values that the neutrino oscillation data implies.

    In other words, only a tiny fraction of the total amount of dark matter is allowed to be in the form of light neutrinos. Given the constraints we have today, we can conclude that approximately 0.5% to 1.5% of the dark matter is made up of neutrinos. This isn’t insignificant; the light neutrinos in the Universe have about the same mass as all the stars in the Universe. But their gravitational effects are minimal, and they cannot make up the needed dark matter.

    THE The Sudbury neutrino observatory, which was instrumental in demonstrating neutrino oscillations and the massiveness of neutrinos. With additional results from atmospheric, solar, and terrestrial observatories and experiments, we may not be able to explain the full suite of what we’ve observed with only 3 Standard Model neutrinos, and a sterile neutrino could still be very interesting as a cold dark matter candidate. (A. B. MCDONALD (QUEEN’S UNIVERSITY) ET AL.,SUDBURY NEUTRINO OBSERVATORY INSTITUTE

    There is an exotic possibility, however, that means we might still have a chance for neutrinos to make a big splash in the world of dark matter: it’s possible that there’s a new, extra type of neutrino. Sure, we have to fit in with all the constraints from particle physics and cosmology that we have already, but there’s a way to make that happen: to demand that if there’s a new, extra neutrino, it’s sterile.

    A sterile neutrino has nothing to do with its gender or fertility; it merely means that it doesn’t interact through the conventional weak interactions today, and that a Z-boson won’t couple to it. But if neutrinos can oscillate between the conventional, active types and a heavier, sterile type, it could not only behave as though it were cold, but could make up 100% of the dark matter. There are experiments that are completed, like LSND and MiniBooNe, as well as experiments planned or in process, like MicroBooNe, PROSPECT, ICARUS and SBND, that are highly suggestive of sterile neutrinos being a real, important part of our Universe.

    LSND experiment at Los Alamos National Laboratory and Virginia Tech>

    FNAL/MiniBooNE

    FNAL/MicrobooNE

    Yale PROSPECT Neutrino experiment


    Yale PROSPECT—A Precision Oscillation and Spectrum Experiment

    INFN Gran Sasso ICARUS, since moved to FNAL


    FNAL/ICARUS

    FNAL Short Baseline Neutrino Detector [SBND]

    Scheme of the MiniBooNE experiment at FNAL

    A high-intensity beam of accelerated protons is focused onto a target, producing pions that decay predominantly into muons and muon neutrinos. The resulting neutrino beam is characterized by the MiniBooNE detector. (APS / ALAN STONEBRAKER)

    If we restrict ourselves to the Standard Model alone, we simply cannot account for the dark matter that must be present in our Universe. None of the particles we know of have the right behavior to explain all of the observations. We can imagine a Universe where neutrinos have relatively large amounts of mass, and that would result in a Universe with significant quantities of dark matter. The only problem is that dark matter would be hot, and lead to an observably different Universe than the one we see today.

    Still, the neutrinos we know of do behave like dark matter, although it only makes up about 1% of the total dark matter out there. That’s not totally insignificant; it equals the mass of all the stars in our Universe! And most excitingly, if there truly is a sterile neutrino species out there, a series of upcoming experiments ought to reveal it over the next few years. Dark matter might be one of the greatest mysteries out there, but thanks to neutrinos, we have a chance at understanding it at least a little bit.

    See the full article here .

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    “Starts With A Bang! is a blog/video blog about cosmology, physics, astronomy, and anything else I find interesting enough to write about. I am a firm believer that the highest good in life is learning, and the greatest evil is willful ignorance. The goal of everything on this site is to help inform you about our world, how we came to be here, and to understand how it all works. As I write these pages for you, I hope to not only explain to you what we know, think, and believe, but how we know it, and why we draw the conclusions we do. It is my hope that you find this interesting, informative, and accessible,” says Ethan

     
  • richardmitnick 9:22 am on March 13, 2019 Permalink | Reply
    Tags: "The Multimessenger Diversity Network: astrophysics joins efforts to broaden participation in STEM", , , , , DOE-U.S. Department of Energy, , Neutrinos, , , U Wisconsin IceCube Collaboration   

    From U Wisconsin IceCube Collaboration- “The Multimessenger Diversity Network: astrophysics joins efforts to broaden participation in STEM” 

    U Wisconsin ICECUBE neutrino detector at the South Pole

    From U Wisconsin IceCube Collaboration

    12 Mar 2019
    Sílvia Bravo

    This past weekend, the first members of the new Multimessenger Diversity Network (MDN) met at the University of Wisconsin–Madison, where they were hosted by the Wisconsin IceCube Particle Astrophysics Center, headquarters of the IceCube Neutrino Observatory.

    The MDN foundational members are LIGO, VERITAS, and LSST observatories together with IceCube.

    CfA/VERITAS, a major ground-based gamma-ray observatory with an array of four 12m optical reflectors for gamma-ray astronomy in the GeV – TeV energy range. Located at Fred Lawrence Whipple Observatory, Mount Hopkins, Arizona, US in AZ, USA, Altitude 2,606 m (8,550 ft)

    The LIGO and IceCube research facilities were built and are operated with support from the National Science Foundation, with contributions from several international agencies. LSST and VERITAS were constructed with funds from the National Science Foundation and the Department of Energy, along with other international agencies. The MDN is an initiative under the umbrella of the INCLUDES National Network, a U.S. statewide program and, along with multimessenger astrophysics, one of the 10 “Big Ideas” for future NSF investments.

    1
    Members of the Multimessenger Diversity Network met face to face for the first time in Madison, WI March 9-10. From left to right: Marcos Santander (IceCube), Jazmine Zuniga-Paiz (MDN student support), Keith Bechtol (LSST), Joey Shapiro Key (LIGO), Jim Madsen (IceCube Ass. Director for Education and Outreach), Segev BenZvi (IceCube), Frank McNally (IceCube), Lauren Corlies (LSST), Amy Furniss (VERITAS), Ellen Bechtol (MDN community manager). Reshmi Mukherjee (VERITAS) and Peter Couvares (LIGO) were not able to join this first meeting.

    The two-day workshop was designed to discuss the vision, goals, and expected outcomes of the network and included ample room for group-wide discussion as well as small group working time. At the end of the meeting, Amy Furniss, assistant professor at California State University, East Bay and representative from VERITAS, reflected, “The potential of MDN is tremendous. Getting everybody in the same room for two days, it became clear that we have so much we can learn from each other and do together in the field to make progress.”

    MDN representatives are poised to become diversity engagement fellows in their collaborations and observatories. This weekend’s meeting included a talk on community management from Lou Woodley, center director at the AAAS Center for Scientific Collaboration and Community Engagement. The CSCCE will offer further training to MDN members at the next in-person meeting of the network in July. Ultimately, MDN representatives will be liaisons between the different observatories and collaborations as well as promoters of collaborative efforts to broaden participation in the field. Segev BenZvi, assistant professor at the University of Rochester and a representative from IceCube, said, “Through MDN, we have an opportunity to promote multimessenger astronomy as an inclusive field. My hope is that the group can build up resources on successful (and unsuccessful) practices to improve equity and diversity, and make it very easy for members of our field to emulate the successes.”

    The MDN, a need and an opportunity

    Multimessenger astrophysics is coming into its own as a network of networks: scientific collaborations with members all around the world, working in experiments funded by agencies in dozens of countries and hosted by facilities in exciting and sometimes remote places on Earth and in space.

    During the last few years, some of the most important results in astrophysics and astronomy have come from collaborative multimessenger research. Now, this successful collaboration can also be the origin of transformative initiatives to broaden participation in astrophysics, physics, and astronomy.

    With support from the NSF INCLUDES program, IceCube invited other observatories to launch this network. After the kick-off meeting in Madison, the MDN will be looking for new partners in neutrino, gravitational-wave, gamma-ray, and cosmic-ray astronomy along with astrophysics. Experiments exploring the universe with lower energy electromagnetic radiation are also welcome. As with science outcomes, every new partner adds valuable insights and expertise to the field.

    2

    Astrophysics observatories are led and run by huge international teams, with great diversity in terms of cultures and geographical origins. However, as with many scientific disciplines, they lack diversity in terms of other demographic indicators, like gender and race, that have been shown to be sources of inequality.

    Increasing diversity and inclusion in multimessenger astronomy is not an easy endeavor. One challenge the multimessenger community faces is connecting with underrepresented communities who do not see suitable role models within these collaborations. The Multimessenger Diversity Network brings together several collaborations in the field to share knowledge, experiences, and practices around broadening participation and to develop shared resources and receive training. After a weekend of insightful discussions, Ellen Bechtol, outreach specialist at WIPAC and the MDN community manager, said, “It was great meeting everyone face to face. I think we all feel enthusiastic about our next steps and I look forward to what we will accomplish together.”

    The next steps of the MDN are continued monthly virtual meetings, a face-to-face meeting and training session with AAAS in July, and collaboration toward a white paper summarizing a long-term strategy for this new INCLUDES network, so that it becomes an enduring multimessenger collaborative effort.

    See the full article here .

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    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.

    IceCube employs more than 5000 detectors lowered on 86 strings into almost 100 holes in the Antarctic ice NSF B. Gudbjartsson, IceCube Collaboration

    Lunar Icecube

    IceCube DeepCore annotated

    IceCube PINGU annotated


    DM-Ice II at IceCube annotated

     
  • richardmitnick 8:36 am on March 13, 2019 Permalink | Reply
    Tags: "MINOS squeezes sterile neutrino’s hiding ground", , , , Neutrinos, ,   

    From CERN Courier: “MINOS squeezes sterile neutrino’s hiding ground” 


    From CERN Courier

    8 March 2019

    FNAL/MINOS

    Newly published results from the MINOS+ experiment at Fermilab in the US cast fresh doubts on the existence of the sterile neutrino – a hypothetical fourth neutrino flavour that would constitute physics beyond the Standard Model.

    Standard Model of Particle Physics


    Standard Model of Particle Physics from Symmetry Magazine

    Neutrino oscillations, predicted more than 60 years ago, and finally confirmed in 1998, explain the observed transmutation of neutrinos from one flavour to another as they travel. Tantalising hints of new-physics effects in short-baseline accelerator-neutrino experiments have persisted since 1995, when the Liquid Scintillator Neutrino Detector (LSND) at Los Alamos National Laboratory reported an 88±23 excess in the number of electron antineutrinos emerging from a muon–antineutrino beam. This suggested that muon antineutrinos were oscillating into electron antineutrinos along the way, but not in the way expected if there are only three neutrino flavours.

    The plot thickened in 2007 when another Fermilab experiment, MiniBooNE, an 818 tonne mineral-oil Cherenkov detector located 541 m downstream from Fermilab’s Booster neutrino beamline, began to see a similar effect. The excess grew, and last November the MiniBooNE collaboration reported a 4.5σ deviation from the predicted event rate for the appearance of electron neutrinos in a muon neutrino beam. In the meantime, theoretical revisions in 2011 meant that measurements of neutrinos from nuclear reactors also show deviations suggestive of sterile-neutrino interference: the so-called “reactor anomaly”.

    Tensions have been running high. The latest results from MINOS+, first reported in 2017 and recently accepted for publication in Physical Review Letters, fail to confirm the MiniBooNE signal. The MINOS+ results are also consistent with those from a comparable analysis of atmospheric neutrinos in 2016 by the IceCube detector at the South Pole. “LSND, MiniBooNE and the reactor data are fairly compatible when interpreted in terms of sterile neutrinos, but they are in stark conflict with the null results from MINOS+ and IceCube,” says theorist Joachim Kopp of CERN. “It might be possible to come up with a model that allows compatibility, but the simplest sterile neutrino models do not allow this.” In late February, the long-baseline T2K experiment in Japan joined the chorus of negative searches for the sterile neutrino, although excluding a different region of parameter space.

    Whereas MiniBooNE and LSND sought to observe a second-order flavour transition (in which a muon neutrino morphs into a sterile and then electron neutrino), MINOS+ and IceCube are sensitive to a first-order muon-to-sterile transition that would reduce the expected flux of muon neutrinos. Such “disappearance” experiments are potentially more sensitive to sterile neutrinos, provided systematic errors are carefully modelled.

    “The MiniBooNE observations interpreted as a pure sterile neutrino oscillation signal are incompatible with the muon-neutrino disappearance data,” says MINOS+ spokesperson Jenny Thomas of University College London. “In the event that the most likely MiniBooNE signal were due to a sterile neutrino, the signal would be unmissable in the MINOS/MINOS+ neutral-current and charged-current data sets.” Taking into account simple unitarity arguments, adds Thomas, the latest MINOS+ analysis is incompatible with the MiniBooNE result at the 2σ level and at 3σ sigma below a “mass-splitting” of 1 eV2 (see figure 1).

    MINOS+ studies how muon neutrinos oscillate into other neutrino flavours as a function of distance travelled, using magnetised-iron detectors located 1 and 735 km downstream from a neutrino beam produced at Fermilab.

    FNAL to Northern Minnesota at the Soudan Mine map

    Neutrino oscillations, predicted more than 60 years ago, and finally confirmed in 1998, explain the observed transmutation of neutrinos from one flavour to another as they travel. Tantalising hints of new-physics effects in short-baseline accelerator-neutrino experiments have persisted since 1995, when the Liquid Scintillator Neutrino Detector (LSND) at Los Alamos National Laboratory reported an 88±23 excess in the number of electron antineutrinos emerging from a muon–antineutrino beam.

    LSND experiment at Los Alamos National Laboratory and Virginia Tech

    This suggested that muon antineutrinos were oscillating into electron antineutrinos along the way, but not in the way expected if there are only three neutrino flavours.

    The plot thickened in 2007 when another Fermilab experiment, MiniBooNE, an 818 tonne mineral-oil Cherenkov detector located 541 m downstream from Fermilab’s Booster neutrino beamline, began to see a similar effect.

    FNAL/MiniBooNE

    The excess grew, and last November the MiniBooNE collaboration reported a 4.5σ deviation from the predicted event rate for the appearance of electron neutrinos in a muon neutrino beam. In the meantime, theoretical revisions in 2011 meant that measurements of neutrinos from nuclear reactors also show deviations suggestive of sterile-neutrino interference: the so-called “reactor anomaly”.

    Tensions have been running high. The latest results from MINOS+, first reported in 2017 and recently accepted for publication in Physical Review Letters, fail to confirm the MiniBooNE signal. The MINOS+ results are also consistent with those from a comparable analysis of atmospheric neutrinos in 2016 by the IceCube detector at the South Pole.

    U Wisconsin ICECUBE neutrino detector at the South Pole

    “LSND, MiniBooNE and the reactor data are fairly compatible when interpreted in terms of sterile neutrinos, but they are in stark conflict with the null results from MINOS+ and IceCube,” says theorist Joachim Kopp of CERN. “It might be possible to come up with a model that allows compatibility, but the simplest sterile neutrino models do not allow this.” In late February, the long-baseline T2K experiment in Japan joined the chorus of negative searches for the sterile neutrino, although excluding a different region of parameter space.

    Whereas MiniBooNE and LSND sought to observe a second-order flavour transition (in which a muon neutrino morphs into a sterile and then electron neutrino), MINOS+ and IceCube are sensitive to a first-order muon-to-sterile transition that would reduce the expected flux of muon neutrinos. Such “disappearance” experiments are potentially more sensitive to sterile neutrinos, provided systematic errors are carefully modelled.

    “The MiniBooNE observations interpreted as a pure sterile neutrino oscillation signal are incompatible with the muon-neutrino disappearance data,” says MINOS+ spokesperson Jenny Thomas of University College London. “In the event that the most likely MiniBooNE signal were due to a sterile neutrino, the signal would be unmissable in the MINOS/MINOS+ neutral-current and charged-current data sets.” Taking into account simple unitarity arguments, adds Thomas, the latest MINOS+ analysis is incompatible with the MiniBooNE result at the 2σ level and at 3σ sigma below a “mass-splitting” of 1 eV2 (see figure 1).

    2
    Fig. 1.

    The sterile-neutrino hypothesis is also in tension with cosmological data, says theorist Silvia Pascoli of Durham University. “Sterile neutrinos with these masses and mixing angles would be copiously produced in the early universe and would make up a significant fraction of hot dark matter. This is somewhat at odds with cosmological observations.”

    One possibility for the surplus electron–neutrino-like events in MiniBooNE is insufficient accuracy in the way neutrino–nucleus interactions in the detector are modelled – a challenge for neutrino-oscillation experiments generally. According to MiniBooNE collaborator Teppei Katori, one effect proposed to account for the MiniBooNE anomaly is neutral-current single-gamma production. “This rare process has many theoretical interests, both within and beyond the Standard Model, but the calculations are not yet tractable at low energies (around 1 GeV) as they are in the non-perturbative QCD region,” he says.

    MINOS+ is now analysing its final dataset and working on a direct comparison with MiniBooNE to look for electron-neutrino appearance as well as the present study on muon-neutrino disappearance. Clarification could also come from other short-baseline experiments at Fermilab, in particular MicroBooNE, which has been operating since 2015, and two liquid-argon detectors ICARUS and SBND (CERN Courier June 2017 p25).

    FNAL/MicrobooNE

    INFN Gran Sasso ICARUS, since moved to FNAL


    FNAL/ICARUS

    FNAL Short Baseline Neutrino Detector [SBND]

    The most exciting possibility is that new physics is at play. “One viable explanation requires a new neutral-current interaction mediated by a new GeV-scale vector boson and sterile neutrinos with masses in the hundreds of MeV,” explains Pascoli. “So far this has not been excluded. And it is theoretically consistent. We have to wait and see.”

    See the full article here .


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    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS

    CERN/ATLAS detector

    ALICE

    CERN/ALICE Detector

    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    LHC

    CERN map

    CERN LHC Grand Tunnel

    CERN LHC particles

     
  • richardmitnick 6:42 pm on March 4, 2019 Permalink | Reply
    Tags: "Hidden ancient neutrinos may shape the patterns of galaxies", Although these cosmic relics suffuse the universe the particles have so little energy that they have never been directly spotted., , , , , In the future improved surveys of galaxies might be sensitive enough to reveal unexpected tweaks to the ring patterns which could be caused by the existence of undiscovered phenomena such as hypotheti, Neutrinos, Neutrinos can shift matter around due to the particles’ gravity slightly changing the distribution of matter in the rings, , Shadowy messengers from the Big Bang have seemingly left their mark on ring-shaped patterns imprinted on the sky, Subatomic particles called neutrinos released just one second after the universe’s birth 13.8 billion years ago continually stream through the universe and are exceedingly hard to spot. But circular, This is the first time evidence of the particles’ fingerprints on galaxies has been spotted   

    From Science News: “Hidden ancient neutrinos may shape the patterns of galaxies” 

    From Science News

    March 4, 2019
    Emily Conover

    Subatomic particles born in the universe’s first second may imprint their effects on the sky.

    1
    RUN IN CIRCLES Galaxies in the universe tend to cluster into rings (illustrated), and scientists have found signs that subatomic particles called neutrinos change the way matter is distributed in the circles. Zosia Rostomian/Lawrence Berkeley National Laboratory

    Shadowy messengers from the Big Bang have seemingly left their mark on ring-shaped patterns imprinted on the sky.

    Subatomic particles called neutrinos, released just one second after the universe’s birth 13.8 billion years ago, continually stream through the universe and are exceedingly hard to spot. But circular patterns of galaxies scattered across the sky reveal signs of the shy particles. Those data hint that the neutrinos’ gravity subtly alters the rings, researchers report February 25 in Nature Physics. Since these relic neutrinos were released so early in the universe’s history, scientists hope they can one day use these particles to better understand the cosmos in its first moments.

    The study “is certainly new and interesting in that it shows that we can derive the early universe physics” by observing the recent universe, says cosmologist Hee-Jong Seo of Ohio University in Athens, who wasn’t involved in the research.

    Spotting signs of the ancient particles is no easy feat. All neutrinos are notoriously difficult to detect. They have no electric charge and can pass straight through other matter. With large, highly sensitive detectors, scientists can spot neutrinos produced by everyday processes such as radioactive decay. But neutrinos released from the Big Bang, known collectively as the “cosmic neutrino background,” are much more elusive. Although these cosmic relics suffuse the universe, the particles have so little energy that they have never been directly spotted.

    So rather than trying to observe those relic neutrinos directly, scientists look for their influence on other cosmic signposts. For example: A pattern caused by sound waves in the early universe — known as baryon acoustic oscillations — should be distorted by the neutrinos. Those sound waves spread outward through the universe like circular ripples on a pond, compressing matter into denser pockets. Eventually, that process resulted in galaxies having a tendency to cluster in rings across the sky (SN: 5/5/12, p. 17).

    But neutrinos can shift that matter around due to the particles’ gravity, slightly changing the distribution of matter in the rings. “You’re seeing the pull of the neutrinos,” says cosmologist Daniel Green. Using data from the Baryon Oscillation Spectroscopic Survey, or BOSS, Green and colleagues studied the circular patterns of galaxies and saw evidence that the neutrinos were, in fact, pulling matter around from the inner side of the ring band toward the outer side.

    Scientists have previously spotted signs of the ancient neutrinos in a glow leftover from the Big Bang. The cosmic microwave background [CMB], light that was released when the universe was just 380,000 years old, is also affected by the cosmic neutrino background.

    CMB per ESA/Planck

    But this is the first time evidence of the particles’ fingerprints on galaxies has been spotted.

    “It’s another hallmark of the success of standard cosmology,” says cosmologist Kevork Abazajian, who was not involved with the research. Still, the current result is just scratching the surface of this phenomenon, making the measurement a proof of principle rather than a definitive detection, says Abazajian, of the University of California, Irvine.

    In the future, improved surveys of galaxies might be sensitive enough to reveal unexpected tweaks to the ring patterns, which could be caused by the existence of undiscovered phenomena, such as hypothetical new types of neutrinos called sterile neutrinos (SN: 6/23/18, p. 7).

    See the full article here .


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  • richardmitnick 1:29 pm on February 23, 2019 Permalink | Reply
    Tags: "An important step towards understanding neutrino masses", , Neutrinos, , ,   

    From U Wisconsin IceCube Collaboration: “An important step towards understanding neutrino masses” 

    U Wisconsin ICECUBE neutrino detector at the South Pole

    From From U Wisconsin IceCube Collaboration

    22 Feb 2019
    Sílvia Bravo

    Neutrinos are used to investigate a broad spectrum of physics topics, ranging from the extreme universe to the underlying symmetries of nature. These intriguing particles may have the answer to a few, long-standing open questions in physics and astronomy. In particular, neutrinos themselves are the origin of still unresolved and maybe totally new physics.

    One of the main open questions in neutrino physics is the relative mass of the three neutrino types, a property known as the neutrino mass ordering. Is the third neutrino more massive than the other neutrinos, in what scientists call the normal ordering (NO), or is it lighter, referred to as inverted ordering (IO)? In a new paper by the IceCube Collaboration, physicists use the inner and denser DeepCore detector within IceCube to try to answer this question. A weak preference is shown for NO, a result that is complementary to and in agreement with results from other experiments. This paper has been submitted to the European Physical Journal.

    1
    The negative log-likelihood (LLH) as a function of sin2(θ23) for Analysis A, relative to the global minimum LLHmin. The preference for NO over IO is visible over all the range of sin2 (θ23) with the best-fit for both orderings being in the lower octant (sin2 (θ23) < 0.5). Image: IceCube Collaboration

    When neutrinos travel through space and matter, they oscillate, meaning they change their flavor (electron, muon or tau) depending on their energy and the propagation distance. This quantum effect is explained by the fact that neutrino mass states, i.e. those for which the mass is a well-defined property, are not the same as the neutrino flavor states, the states in which neutrinos interact. These mass states are called neutrinos 1, 2 and 3.

    But we know very little about neutrino mass, except that for all neutrinos it is very small and that nature may work fairly differently depending on which neutrino is more massive. Some unification theories, for example, predict a normal mass ordering. Also depending on this mass ordering, the outcomes of a supernova explosion might be different.

    Several current and future long-baseline accelerator experiments, as well as experiments with atmospheric neutrinos and reactor neutrinos, are targeting a precise measurement of the mass ordering. For atmospheric neutrinos, the propagation through Earth induces a small modulation of the oscillation of neutrinos below 15 GeV, at about the lowest neutrino energies detected in IceCube. Interestingly, this modulation depends on the mass ordering. The high statistics of detected neutrinos within IceCube allows us to search for this small effect.

    In this study, researchers performed two independent analyses, both using three years of IceCube data and targeting this challenging measurement of the neutrino mass ordering with low-energy atmospheric neutrinos in IceCube. “When we embarked on this new analysis we were not aware of all the experimental challenges that we had to solve to measure the faint signals of these low-energy neutrinos with a sufficient precision,” says Martin Leuermann, a main analyzer of this study who worked on this analysis as a PhD candidate at RWTH Aachen University.

    Both analyses obtain a consistent result within their uncertainties and a small preference for NO. Although the ordering signature is very weak, it provides a complimentary measurement. Unlike beam experiments, this result is independent of the CP-violating phase, another important parameter for characterizing neutrino oscillations. Another valuable outcome of this study is the successful implementation and verification of analysis methods that have been prototyped for future extensions of IceCube such as PINGU or the imminent IceCube Upgrade.

    The IceCube Upgrade is already underway and is expected to be completed by 2023. It will deploy new sensors within DeepCore, which will greatly enhance the accuracy of detecting these lowest energy neutrinos in IceCube that are most critical for this measurement. “We have now proven that the concept of future extensions of IceCube do work in practice and thus we can look forward to unprecedented measurements of neutrino properties,” says Steven Wren, also a main analyzer of this study who worked on this analysis as a PhD candidate at the University of Manchester.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition
    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.

    IceCube employs more than 5000 detectors lowered on 86 strings into almost 100 holes in the Antarctic ice NSF B. Gudbjartsson, IceCube Collaboration

    Lunar Icecube

    IceCube DeepCore annotated

    IceCube PINGU annotated


    DM-Ice II at IceCube annotated

     
  • richardmitnick 4:01 pm on February 18, 2019 Permalink | Reply
    Tags: A new technique dubbed STeVE for “starting TeV events, A second technique called LESE for low-energy starting events, , , , Both of these techniques introduce a new online event selection filter that selects starting events based on an initial fast reconstruction, , , Gamma-ray emission, However gamma rays can also be produced in environments where neutrino emission would be disfavored, Neutrinos, Searches combining both techniques result in an effective area comparable to ANTARES which thanks to its location in the Mediterranean Sea has a priori a better neutrino view of our galaxy, STeVE and LESE where tested with 3 and 4 years of IceCube data respectively, The gamma-ray galactic sky shows a large concentration of sources in the Southern Hemisphere, The highest energy gamma rays could be produced in the same mechanisms that produce the highest energy neutrinos,   

    From U Wisconsin IceCube Collaboration: “Improving searches for galactic sources of high-energy neutrinos” 

    U Wisconsin ICECUBE neutrino detector at the South Pole

    18 Feb 2019
    Sílvia Bravo

    The search for sources of high-energy neutrinos and cosmic rays has revealed neutrinos from distant galaxies and from all over the sky traveling through the Antarctic ice. Closer sources, though, those that could produce neutrino emission in the Milky Way, have been more elusive.

    In IceCube, the signature of sources such as galactic supernova remnants peaks at low energies, well below 100 TeV, where the large background of atmospheric muons is difficult to filter out. The bulk of galactic neutrino emission is expected in the southern sky, where the Earth cannot serve as a natural filter to remove the million-to-one muon-neutrino signal. In a recent paper by the IceCube Collaboration, two new techniques improve searches at energies from 100 TeV down to 100 GeV. When tested with a few years of IceCube data, these new selections improve the sensitivity and discovery potential, allowing for the first time the search for galactic point-like sources using track events created by muon neutrinos that in many cases are indistinguishable from atmospheric muon tracks. These results have just been submitted to the journal Astroparticle Physics.

    1
    The differential discovery potential at −60° declination for LESE (light blue), STeVE (dark blue), the combined selection (LESE +STeVE) (red), a cascade point-source search (gray), a starting tracks search targeting higher energies (MESE) (gray dashed), throughgoing (light gray dashed), all with the IceCube detector, and of the ANTARES point-like source search (black). In this plot, all results are calculated for an equal three-year exposure. Image: IceCube Collaboration

    Scientists have speculated that at high energies neutrino emission should be associated with gamma-ray emission, since the highest energy gamma rays could be produced in the same mechanisms that produce the highest energy neutrinos. However, gamma rays can also be produced in environments where neutrino emission would be disfavored.

    The gamma-ray galactic sky shows a large concentration of sources in the Southern Hemisphere, where both the galactic center and the majority of the galactic plane are seen from Earth. This is, thus, a region worth exploring with IceCube to look for potential neutrino emission from the same sources that produce the gamma rays.

    However, the most successful searches for high-energy neutrinos select particle interactions that start in the detector—both cascade- and track-like events—or track-like events that come from the northern sky. Track-like events are those that provide a good pointing resolution, which on average is well below 1 degree.

    In previous searches for astrophysical neutrinos using events with the interaction vertex within the detector, a fairly high energy cut was also applied to obtain an efficient selection. The concern is that the majority of galactic neutrino emission could happen at lower energies and, thus, might be removed with this cut. To lower this energy threshold and still preserve a good pointing resolution in the southern sky, researchers have looked closer at track events in IceCube.

    In a new technique dubbed STeVE, for “starting TeV events,” the selection focuses on neutrino events between 10 and 100 TeV and uses techniques developed in a previous IceCube analysis (link to MESE news 414) to remove the background of multiple parallel atmospheric muon events, which has proved to be a resistant background at low energies. In addition, this event selection strategy exploits the difference in the observed photon pattern of bundles of low-energy atmospheric muons compared to individual high-energy muons.

    In a second technique, called LESE, for low-energy starting events, the selection was optimized for neutrinos below 10 TeV. At low energies and due to the small granularity of the IceCube detector, with strings of sensors deployed at horizontal distances of 125 meters, it’s easier for muon tracks to enter the detector without significant energy deposition detected by the outer layers of sensors, which mimics a muon neutrino interacting within the detector volume. LESE aims at selecting track-like events with energies as low as 100 GeV, leveraging the experience gained with veto-based selection techniques in searches for dark matter.

    Both of these techniques introduce a new online event selection filter that selects starting events based on an initial fast reconstruction. This new filter is the first to accept starting events from the entire southern sky while maintaining as large as possible active detector volume.

    STeVE and LESE where tested with 3 and 4 years of IceCube data, respectively, in a search for sources of astrophysical neutrinos anywhere in the southern sky and for neutrino emission from the direction of 96 known gamma-ray sources. No significant excess of neutrino emission was found, but the techniques have proven to be sensitive to strong galactic sources of low-energy astrophysical neutrinos.

    “Studying starting events from the southern sky at these energies poses many new challenges,” explains Rickard Ström, a main analyzer who worked on this study as a PhD candidate at Uppsala University. “We leveraged expertise from previous searches for point sources and exotic signatures such as dark matter. This was the first time IceCube was able to study point sources in the southern sky at these energies and using tracks with degree precision,” adds Ström.

    Searches combining both techniques result in an effective area comparable to ANTARES, which thanks to its location in the Mediterranean Sea has a priori a better neutrino view of our galaxy. STeVE and LESE selections reduce the muon background to a few thousand events per year and significantly improve IceCube’s sensitive and discovery potential of point-like sources in the southern sky with neutrinos with energies below 100 TeV.

    From From U Wisconsin IceCube Collaboration

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition
    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.

    IceCube employs more than 5000 detectors lowered on 86 strings into almost 100 holes in the Antarctic ice NSF B. Gudbjartsson, IceCube Collaboration

    Lunar Icecube

    IceCube DeepCore annotated

    IceCube PINGU annotated


    DM-Ice II at IceCube annotated

     
  • richardmitnick 11:36 am on February 14, 2019 Permalink | Reply
    Tags: , , , Neutrinos, ,   

    From Sanford Underground Research Facility: “Enhancing the search” 

    SURF logo
    Sanford Underground levels

    2.13.19
    Erin Broberg

    Photos by Matt Kapust

    From Sanford Underground Research Facility

    Changes in LUX’s design optimize LZ’s search for dark matter.

    1

    2
    LUX cryostat

    To increase the amount of xenon atoms in a given volume, scientists cool xenon gas to very low temperatures until it becomes liquid. To keep the experiment cold, it is housed in a double-walled titanium vessel to maintain the low temperature, a cryostat. The LUX cryostat held 380 kg of LXe.

    The LUX cryostat held 380 kilograms of liquid xenon.

    3
    LZ cryostat

    LZ will hold 10 tons of liquid xenon, over 26 times the volume previously contained by LUX. This increases the chances for a WIMP to collide with a xenon atom, causing a series of signatures to be detected.

    4
    LUX PMTs

    Essential to the detection of WIMP signatures are two arrays of photomultiplier tubes (PMTs), housed at the top and bottom of the cryostat.

    The arrays in LUX held a combined 122 PMTs, each with a two-inch diameter.

    5
    LZ PMTs

    With a larger volume of xenon to monitor, researchers have designed larger PMT arrays. LZ will boast a total of 494 PMTs, three inches in diameter, in the top and bottom arrays.

    To optimize both their detection and veto capabilities, researchers have included additional PMTs in the skin and dome structures of the detector.

    6

    “In addition to the size, we are improving every aspect of the experiment that we can,” Horn said.

    To transport and store the xenon, LUX previously used eight compressed gas cylinders. LZ will use 200 of these cylinders stored in a newly outfitted room outside the laboratory underground.

    More xenon means a larger, more complex circulation system. Previously, the pumps exchanged 25 liters of purified xenon gas per minute. The small pumps will be replaced with large compressors capable of circulating xenon efficiently. Now, that number will be closer to 200 liters per minute.

    A xenon tower outside the water tank will allow xenon to be heated to its gaseous form, purified, then re-liquified before it is reintroduced into the detector again.

    The signal readouts for all photomultipliers and sensors amount to over 1000 cables which will run out of the detector and into computer racks. Also, the voltages required to create the electric field over the increased detector size are significantly higher.

    “Overall, there are far more challenges, more sub-systems and simply far more pieces to this experiment – all bigger and better than before”, said Horn.

    7
    Increasing veto detection

    LUX relied on the water tank as a veto detector, helping researchers rule out extraneous signatures.

    In addition to the water tank, LZ will improve veto detection by installing nine acrylic vessels around the cryostat, filled with a liquid scintillator and and monitored by larger PMTs (8-inch diameter) within the water tank. This system allows researchers to further reduce backgrounds by by observing interactions outside the detector.

    In 2013, the Large Underground Xenon detector (LUX) at Sanford Underground Research Facility (Sanford Lab) was named the most sensitive dark matter detector in the world. In the global search for Weakly Interacting Massive Particles (WIMPs), a candidate for dark matter, LUX was preforming exceedingly well.

    So why did the collaboration decommission LUX in 2016? And why are they building a larger detector—LUX-ZEPLIN (LZ)—in it’s place?

    “The search for dark matter is a numbers’ game,” said Markus Horn, Sanford Lab research scientist and member of the LZ collaboration. “We’re waiting for a dark matter particle or weakly interacting massive particle (WIMP) to interact with the xenon atoms in the detector. The likelihood of such an interaction depends on how many xenon atoms we have.”

    By sizing up the experiment, researchers increase their chances of witnessing rare WIMP interactions with a larger volume to hold xenon. Horn said that, while the size of the detector isn’t the only way researchers are enhancing the search, it’s a good starting point.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    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

    LBNL LZ project will replace LUX at SURF [see below].

    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.

    LUX’s mission was to scour the universe for WIMPs, vetoing all other signatures. It would continue to do just that for another three years before it was decommissioned in 2016.

    In the midst of the excitement over first results, the LUX collaboration was already casting its gaze forward. Planning for a next-generation dark matter experiment at Sanford Lab was already under way. Named LUX-ZEPLIN (LZ), the next-generation experiment would increase the sensitivity of LUX 100 times.

    SLAC physicist Tom Shutt, a previous co-spokesperson for LUX, said one goal of the experiment was to figure out how to build an even larger detector.
    “LZ will be a thousand times more sensitive than the LUX detector,” Shutt said. “It will just begin to see an irreducible background of neutrinos that may ultimately set the limit to our ability to measure dark matter.”
    We celebrate five years of LUX, and look into the steps being taken toward the much larger and far more sensitive experiment.

    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
    LBNE

    U Washington Majorana Demonstrator Experiment at SURF

    The MAJORANA DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment in the Sanford Underground Research Facility (SURF) in Lead, SD. The goal of the DEMONSTRATOR is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76Ge 0νββ Q-value at 2039 keV. MAJORANA plans to collaborate with GERDA for a future tonne-scale 76Ge 0νββ search.

    LBNL LZ project at SURF, Lead, SD, USA

    CASPAR at SURF


    CASPAR is a low-energy particle accelerator that allows researchers to study processes that take place inside collapsing stars.

    The scientists are using space in the Sanford Underground Research Facility (SURF) in Lead, South Dakota, to work on a project called the Compact Accelerator System for Performing Astrophysical Research (CASPAR). CASPAR uses a low-energy particle accelerator that will allow researchers to mimic nuclear fusion reactions in stars. If successful, their findings could help complete our picture of how the elements in our universe are built. “Nuclear astrophysics is about what goes on inside the star, not outside of it,” said Dan Robertson, a Notre Dame assistant research professor of astrophysics working on CASPAR. “It is not observational, but experimental. The idea is to reproduce the stellar environment, to reproduce the reactions within a star.”

     
  • richardmitnick 2:03 pm on February 5, 2019 Permalink | Reply
    Tags: A new source for Majorana calibration, , Cobalt-56 is an ideal source-Cobalt-56 has a really short half-life only 77 days, , Neutrinos, , , The collaboration has been using its thorium source for five years- the signatures it produces are at a slightly higher energy level than that at which neutrinoless double-beta decay is expected to oc, Thorium lasts for years. Indeed the collaboration has been using its thorium source for five years,   

    From Sanford Underground Research Facility: “A new source for Majorana calibration” 

    SURF logo
    Sanford Underground levels

    From Sanford Underground Research Facility

    February 4, 2019
    Erin Broberg

    Researchers recently got a special delivery: a hundred million atoms of Cobalt-56, an ideal calibration source.

    1
    A string of germanium detectors inside a cleanroom glovebox on the 4850 Level of Sanford Lab, before they were installed in the Majorana Demonstrator in 2016.
    Photo by Matthew Kapust

    U Washington Majorana Demonstrator Experiment at SURF

    Researchers have not seen the copper glow of the Majorana Demonstrator’s internal detector since 2016. Sealed behind six layers, including 5,200 lead bricks and two heavy copper shields, the Majorana Demonstrator has recorded a steady stream of data that will inform the next-generation neutrinoless double-beta decay experiments. But how do researchers know if the information they’re receiving is accurate? How do they know something hasn’t gone amiss deep inside?

    Simple. They use an advanced calibration system that allows them to monitor the performance of the germanium detectors that make up the heart of the demonstrator. Ralph Massarczyk, staff scientist at Los Alamos National Laboratory, designed and created the calibration system used by the Majorana Demonstrator collaboration.

    “In a typical detector,” Massarczyk explains, “there is enough natural background that you can easily calibrate a detector. But with Majorana, you have a very minimal background, which is not enough to determine its performance.”

    Without substantial background data, researchers don’t know if the background is stable or not. The detector could be reporting events at inaccurate energy levels or even missing them completely. So, to calibrate this extremely sensitive detector, a calibration source is used to produce a standard set of well-known physics events that researchers can use to understand detector performance.

    Typically, the collaboration uses thorium, a naturally occurring, slightly radioactive material that creates signatures the Majorana Demonstrator can easily read. The only problem with this source is that the signatures it produces are at a slightly higher energy level than that at which neutrinoless double-beta decay is expected to occur.

    For a more ideal calibration, Massarczyk and his team got a special delivery: a hundred million atoms of Cobalt-56, a slightly radioactive isotope created in particle accelerators and used mostly in the medical field. The source underwent several “swipe tests” to ensure no leaks had occurred.

    “Cobalt-56 is an ideal source. It produces a lot of events, and those events are at the exact energy where we expect to see a neutrinoless double-beta decay event,” Massarczyk said.

    If it is such a perfect indicator, why don’t researchers use it every time?

    “Cobalt-56 has a really short half-life, only 77 days,” said Massarczyk. “This means that at the end of 77 days, only one-half of the source will be left. After waiting another 77 days, only one-fourth will be left. After a year, the source is gone.”

    Thorium, on the other hand, lasts for years. Indeed, the collaboration has been using its thorium source for five years, Massarczyk said.

    Delivery methods

    To deliver a calibration source to the detector modules behind layers of shielding, Massarczyk designed a “line source.” In this system, a 5-meter long, half-inch thick plastic tube is inserted into a track from the outside of the shield. The tube, which carries the calibration source, is pushed along the “grooves” on the outside of each detector module, snaking its way around twice.

    “It sort of resembles a helix,” Massarczyk said. “This way, the signals are distributed evenly, rather than coming from one point, allowing each detector within the modules to see activity from the same source.”

    The normal rate for the Majorana Demonstrator is a few signature counts per hour. When a radioactive calibration source is included, researchers see a few thousand events per second. During its weekly calibration run, the Majorana Demonstrator sees more events in 3 hours than it would otherwise detect in the span of 120 years.

    “If, while this source is inside, the demonstrator creates signals that correspond with known data, then we know the demonstrator is well-calibrated and on track,” Massarczyk said.

    Looking to the future

    The Majorana Demonstrator is expected to run for a few more years, so the short half-life of Cobalt-56 means it is not a sustainable calibration option for the team. That’s why this week’s calibration was so important. The data collected has been sent to analysts for interpretation.

    “The main purpose for this data is to double-check the data analysis we do in the energy region 2MeV, where we expect the neutrinoless double-beta decay events to occur,” Massarczyk said.

    The information gained from these tests also is of interest to collaborators with LEGEND (Large Enriched Germanium Experiment for Neutrinoless ββ Decay), who are trying to perfect the next-generation neutrinoless double-beta decay experiment.

    Legend Collaboration UNC Chapel Hill

    “As they plan a ton-scale experiment, researchers want to know if the materials are clean enough, if the shielding is working and how far underground they need to go,” said Massarczyk. “Understanding the backgrounds gives us important information to make those decisions.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    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.

    LUX’s mission was to scour the universe for WIMPs, vetoing all other signatures. It would continue to do just that for another three years before it was decommissioned in 2016.

    In the midst of the excitement over first results, the LUX collaboration was already casting its gaze forward. Planning for a next-generation dark matter experiment at Sanford Lab was already under way. Named LUX-ZEPLIN (LZ), the next-generation experiment would increase the sensitivity of LUX 100 times.

    SLAC physicist Tom Shutt, a previous co-spokesperson for LUX, said one goal of the experiment was to figure out how to build an even larger detector.
    “LZ will be a thousand times more sensitive than the LUX detector,” Shutt said. “It will just begin to see an irreducible background of neutrinos that may ultimately set the limit to our ability to measure dark matter.”
    We celebrate five years of LUX, and look into the steps being taken toward the much larger and far more sensitive experiment.

    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
    LBNE

    U Washington Majorana Demonstrator Experiment at SURF

    The MAJORANA DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment in the Sanford Underground Research Facility (SURF) in Lead, SD. The goal of the DEMONSTRATOR is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76Ge 0νββ Q-value at 2039 keV. MAJORANA plans to collaborate with GERDA for a future tonne-scale 76Ge 0νββ search.

    LBNL LZ project at SURF, Lead, SD, USA

    CASPAR at SURF


    CASPAR is a low-energy particle accelerator that allows researchers to study processes that take place inside collapsing stars.

    The scientists are using space in the Sanford Underground Research Facility (SURF) in Lead, South Dakota, to work on a project called the Compact Accelerator System for Performing Astrophysical Research (CASPAR). CASPAR uses a low-energy particle accelerator that will allow researchers to mimic nuclear fusion reactions in stars. If successful, their findings could help complete our picture of how the elements in our universe are built. “Nuclear astrophysics is about what goes on inside the star, not outside of it,” said Dan Robertson, a Notre Dame assistant research professor of astrophysics working on CASPAR. “It is not observational, but experimental. The idea is to reproduce the stellar environment, to reproduce the reactions within a star.”

     
  • richardmitnick 1:14 pm on February 5, 2019 Permalink | Reply
    Tags: ArgoNeuT collaboration, ArgoNeuT hits a home run with measurements of neutrinos in liquid argon, , , High-energy particle physics, liquid-argon technology-ArgoNeuT was a neutrino detector filled with 170 liters of liquid argon, Neutrinos,   

    From Fermi National Accelerator Lab: “ArgoNeuT hits a home run with measurements of neutrinos in liquid argon” 

    FNAL II photo

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    From Fermi National Accelerator Lab , an enduring source of strength for the US contribution to scientific research world wide.

    February 1, 2019
    Giacomo Scanavini
    Tingjun Yang

    All baseball fans know that probability is a huge component of their favorite sport. Just as, when you roll a die, you know that a certain outcome has a one in six chance of showing up, in baseball, each batter has a certain probability of hitting the ball based on their skills. Analogously, physicists are aware of the probabilistic nature of the interactions between particles and want to measure these probabilities to understand how nature works. A particle in a beam moving toward a fixed target can be imagined as a baseball, thrown by a pitcher, heading to a batter. The particle will not “hit” (interact) with a certainty of 100 percent. Depending on both the particle and the target, that probability changes, and it may be very low.

    What do physicists do in that case? They simply throw a lot of identical particles at a specific target in order to collect a reasonable number of interactions to investigate. Studying how particles interact with different targets in a statistical way can unveil nature’s secrets.

    Fermilab ArgoNeuT

    ArgoNeuT detector at Fermilab used liquid argon to detect mysterious particles called neutrinos. Photo ArgoNeuT collaboration

    The impact

    The particle known as the neutrino interacts very rarely with matter. It comes in three types, and while traveling, there is a probability they morph from one of their types into another. This process is known as neutrino oscillation, and it’s one of the most active research topics related to these curious particles today.

    Neutrino-nucleus interaction probabilities are a fundamental prerequisite for every neutrino oscillation experiment. In high-energy particle physics, such probability is expressed in terms of an area, called cross-section. In order to correctly interpret the outcome of neutrino oscillation experiments, researchers need precise neutrino cross-section measurements in the desired energy range.

    Neutrinos that interact with a nucleus produce other particles that scientists study to learn more about the neutrino responsible for the interaction.

    ArgoNeuT was a neutrino detector filled with 170 liters of liquid argon. It was designed to study neutrinos produced in a beam, but more specifically to exploit and fully understand what scientists now call liquid-argon technology, because it makes use of the liquid argon as the neutrino’s target.

    Using data collected over six months by this detector at Fermilab, ArgoNeuT researchers measured the probability for a neutrino to interact with a nucleus of argon to produce a particular result: one muon, exactly one charged pion and any number of nucleons (protons and neutrons).

    During the analysis of the ArgoNeuT data, scientists made fundamental improvements in the software that reconstructs the particles in the detector. These tools use the data to reconstruct – create a picture – and identify the particles produced in the interaction. The same reconstruction tools will be used by current and future neutrino experiments that use liquid argon as the detection material, such as the MicroBooNE and SBND experiments at Fermilab.

    FNAL/MicroBooNE

    FNAL Short-Baseline Near Detector

    Moreover, these measurements provide new information about the neutrino single-pion production and can be used to improve the modeling of neutrino interactions with the argon nucleus.

    1
    A negative muon and positive pion candidate event in ArgoNeuT. The figure shows the 2-D projections in the two wire planes. The color of the track respects the charge read by the wire planes, wire by wire.

    Summary

    The ArgoNeuT experiment was the first ever to make cross-section measurements of neutrino and antineutrino (the neutrino’s antimatter counterpart) interactions resulting in a muon, a charged pion and any number of nucleons in the final state using argon as the target.

    Charged particles moving in the detector leave behind marks of their passage that can be read and recorded. Because of the structure of the detector, this information can be interpreted as a quantity of electric charge, proportional to the particle’s energy, divided into small dots along the particle’s path. In order to consider a particle “reconstructed,” all the dots must be grouped in a cluster, more or less like solving a connect-the-dots puzzle (without the help given by numbered labels arranged in ascending order!).

    Scientists can identify the types of particles that move through the detector based on their tracks.

    Researchers on ArgoNeuT managed to solve a series of issues. One was to account for the pesky presence of muons that happened to have no affiliation with any neutrino interaction in the detector. Such muons would arise from neutrino interactions with the environment surrounding the detector. They also took on the challenge of optimizing the reconstruction software for this analysis. The improved software was able to clusterize all the dots in the neutrino events in a more consistent and realistic way.

    Besides a chain of cuts able to remove the events that clearly didn’t respected the desired event structure, ArgoNeuT researchers implemented a boosted decision tree. This is a technique for creating a model that separates events according to several carefully chosen parameters given as inputs from the user. The boosted decision tree was trained using simulated signal and background samples, further improving the separation between signal and background data.

    After correcting for selection efficiency, scientists carried out the measurements and compared them with four of the most commonly used neutrino event simulators. The comparison showed a mismatch between data and most of the neutrino simulation predictions, showing how much physicists still have to understand about neutrino-argon and neutrino-nucleus interactions. The results obtained in these measurements can help improve the simulators taking into account more recent data from neutrino-argon interactions. Furthermore, because of the software’s great performance, ArgoNeuT will aid larger neutrino experiments in their quest to understand the nature of the subtle neutrino.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    FNAL Icon

    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.

    FNAL MINERvA front face Photo Reidar Hahn

    FNAL DAMIC

    FNAL Muon g-2 studio

    FNAL Short-Baseline Near Detector under construction

    FNAL Mu2e solenoid

    Dark Energy Camera [DECam], built at FNAL

    FNAL DUNE Argon tank at SURF

    FNAL/MicrobooNE

    FNAL Don Lincoln

    FNAL/MINOS

    FNAL Cryomodule Testing Facility

    FNAL Minos Far Detector

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    FNAL/NOvA experiment map

    FNAL NOvA Near Detector

    FNAL ICARUS

    FNAL Holometer

     
  • richardmitnick 5:12 pm on February 4, 2019 Permalink | Reply
    Tags: , , , Neutrinos   

    From Fermi National Accelerator Lab: “CSI: Neutrinos cast no shadows” 

    FNAL II photo

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    From Fermi National Accelerator Lab , an enduring source of strength for the US contribution to scientific research world wide.

    February 4, 2019
    Xianguo Lu

    Scientists solve neutrino mysteries by watching them interact with detectors — specifically, with the atomic nuclei in the detector material. Most of the time, a neutrino does not even shake hands with a nucleus. But when it does, the lightweight, neutral particle can transform into a charged particle and knock things out of the nucleus as it escapes — leaving a crime scene behind. It is the job of scientists at Fermilab’s MINERvA [see below] experiment to reconstruct the crime scene and figure out what has happened during the interaction.

    The impact

    Neutrinos are lightweight particles that rarely interact with matter. Their reluctance to interact makes them difficult to study, but they’re also the very particles that could answer longstanding questions about the creation of the cosmos, so they’re worth the pursuit. And it’s a tough one, since the neutrino can’t be studied directly. Rather, scientists must study the traces it leaves behind. The more information they can gather about the meaning of those traces, the better their neutrino measurements — not just at MINERvA, but at other neutrino experiments as well.

    Summary

    Neutrinos are lightweight, neutral particles, and they usually sail through matter without bumping into it. But once in a while, it does shake hands with a nucleus, and sometimes the handshake takes a destructive turn: A charged lepton (an electron or muon, sometimes called a “heavy electron”) is produced, while the constituents of the nucleus are knocked out. The traces of the charged lepton and the knock-out are collected by a particle detector.

    MINERvA scientists study the resultant particles’ traces to reconstruct the interaction between the neutrinos and the nuclei. So far, this has not been an easy task: Nuclear effects have obscured much of the evidence of the intruding neutrinos, leaving researchers with complex and seemingly irrelevant information. Not all neutrinos misbehave but, unfortunately, the neutrinos we care about – those with energy comparable to the mass of the constituents of the nuclei and could possibly tell us about the creation of the cosmos – all have this modus operandi.

    1
    The transverse boosting angle δαT represents the direction of the net transverse motion of the charged lepton and the knock-out.

    To reconstruct the resulting crime scene, scientists need a complete understanding of how the nuclear effects work.

    Both the charged lepton and the knock-out retain partial fingerprints from the original neutrino, and those partial fingerprints lie ambiguously on top of the nuclear effect background.

    Researchers have found that the fingerprints can be lifted via a novel neutrino CSI technique known as “final-state correlations.” Just as the sun’s corona is visible only during a solar eclipse, the fine details of the nuclear effects become clear only when other effects are removed.

    To get a sense of the “final-state correlations” technique, let’s take a step back and look at the events leading to the crime scene: A neutrino bumps into a nucleus. The interaction produces other particles. Those new particles — charged lepton and knock-out — fly off in opposite directions, leaving traces of themselves in the detector.

    In the absence of nuclear effects, the charged lepton and the knock-out would fly off in separate, roughly back-to-back paths, away from the incoming neutrino path. Picture a neutrino entering through, say, the south entrance of some tiny, subatomic building. It bumps into a nucleus. The resulting charged lepton flees through an east exit, and the knock-out particle flees through some west exit.

    With no nuclear effects, the charged lepton heads east with as much determination as the knock-out particle heads west. That is, the charge lepton’s east-pointing momentum matches the knock-out particle’s west-pointing momentum.

    But in reality, there are nuclear effects, and that means that the charged lepton’s eastward motion does not match the knock-out particle’s westward motion. These subtle momentum differences are clues; they reflect everything that happens inside the nucleus, like a shadow of the crime scene cast by the flashlight carried by the neutrino. Thus, neutrinos cast no shadows – only nuclear effects do.

    The final-state correlations technique matches the nuclear effects with the postinteraction particles’ departures from the paths of equal east-west momenta.

    In a recent MINERvA neutrino investigation, researchers used the new technique. They laid out a detailed reconstruction of the nuclear effects. The underlying phenomena – such as the initial state of the nucleus, additional knock-out mechanism, and final-state interactions between the knock-out and the rest of the nucleus – are now separated. New insights on the workings of nuclear effects have been reported in Phys. Rev. Lett. 121, 022504. Those interested are much encouraged to review MINERvA’s findings.

    Xianguo Lu is a physicist at the University of Oxford.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    FNAL Icon

    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.

    FNAL MINERvA front face Photo Reidar Hahn

    FNAL DAMIC

    FNAL Muon g-2 studio

    FNAL Short-Baseline Near Detector under construction

    FNAL Mu2e solenoid

    Dark Energy Camera [DECam], built at FNAL

    FNAL DUNE Argon tank at SURF

    FNAL/MicrobooNE

    FNAL Don Lincoln

    FNAL/MINOS

    FNAL Cryomodule Testing Facility

    FNAL Minos Far Detector

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    FNAL/NOvA experiment map

    FNAL NOvA Near Detector

    FNAL ICARUS

    FNAL Holometer

     
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