Tagged: Dark Matter Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 9:55 pm on September 5, 2017 Permalink | Reply
    Tags: , , , , , , Dark Matter, , , , , , ,   

    From Symmetry: “What can particles tell us about the cosmos?” 

    Symmetry Mag
    Symmetry

    09/05/17
    Amanda Solliday

    The minuscule and the immense can reveal quite a bit about each other.

    In particle physics, scientists study the properties of the smallest bits of matter and how they interact. Another branch of physics—astrophysics—creates and tests theories about what’s happening across our vast universe.

    1
    The current theoretical framework that describes elementary particles and their forces, known as the Standard Model, is based on experiments that started in 1897 with the discovery of the electron. Today, we know that there are six leptons, six quarks, four force carriers and a Higgs boson. Scientists all over the world predicted the existence of these particles and then carried out the experiments that led to their discoveries. Learn all about the who, what, where and when of the discoveries that led to a better understanding of the foundations of our universe.

    While particle physics and astrophysics appear to focus on opposite ends of a spectrum, scientists in the two fields actually depend on one another. Several current lines of inquiry link the very large to the very small.

    The seeds of cosmic structure

    For one, particle physicists and astrophysicists both ask questions about the growth of the early universe.

    In her office at Stanford University, Eva Silverstein explains her work parsing the mathematical details of the fastest period of that growth, called cosmic inflation.

    Lambda-Cold Dark Matter, Accelerated Expansion of the Universe, Big Bang-Inflation (timeline of the universe) Date 2010 Credit: Alex MittelmannColdcreation

    “To me, the subject is particularly interesting because you can understand the origin of structure in the universe,” says Silverstein, a professor of physics at Stanford and the Kavli Institute for Particle Astrophysics and Cosmology. “This paradigm known as inflation accounts for the origin of structure in the most simple and beautiful way a physicist can imagine.”

    Scientists think that after the Big Bang, the universe cooled, and particles began to combine into hydrogen atoms. This process released previously trapped photons—elementary particles of light.

    The glow from that light, called the cosmic microwave background, lingers in the sky today.

    CMB per ESA/Planck

    Scientists measure different characteristics of the cosmic microwave background to learn more about what happened in those first moments after the Big Bang.

    According to scientists’ models, a pattern that first formed on the subatomic level eventually became the underpinning of the structure of the entire universe. Places that were dense with subatomic particles—or even just virtual fluctuations of subatomic particles—attracted more and more matter. As the universe grew, these areas of density became the locations where galaxies and galaxy clusters formed. The very small grew up to be the very large.

    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    Scientists studying the cosmic microwave background hope to learn about more than just how the universe grew—it could also offer insight into dark matter, dark energy and the mass of the neutrino.

    Dark Matter

    Dark matter cosmic web and the large-scale structure it forms The Millenium Simulation, V. Springel et al

    Dark Matter Particle Explorer China

    DEAP Dark Matter detector, The DEAP-3600, suspended in the SNOLAB deep in Sudbury’s Creighton Mine

    LUX Dark matter Experiment at SURF, Lead, SD, USA

    ADMX Axion Dark Matter Experiment, U Uashington

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

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


    FNAL DUNE Argon tank at SURF


    Surf-Dune/LBNF Caverns at Sanford



    SURF building in Lead SD USA

    “It’s amazing that we can probe what was going on almost 14 billion years ago,” Silverstein says. “We can’t learn everything that was going on, but we can still learn an incredible amount about the contents and interactions.”

    For many scientists, “the urge to trace the history of the universe back to its beginnings is irresistible,” wrote theoretical physicist Stephen Weinberg in his 1977 book The First Three Minutes. The Nobel laureate added, “From the start of modern science in the sixteenth and seventeenth centuries, physicists and astronomers have returned again and again to the problem of the origin of the universe.”

    Searching in the dark

    Particle physicists and astrophysicists both think about dark matter and dark energy. Astrophysicists want to know what made up the early universe and what makes up our universe today. Particle physicists want to know whether there are undiscovered particles and forces out there for the finding.

    “Dark matter makes up most of the matter in the universe, yet no known particles in the Standard Model [of particle physics] have the properties that it should possess,” says Michael Peskin, a professor of theoretical physics at SLAC.

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    “Dark matter should be very weakly interacting, heavy or slow-moving, and stable over the lifetime of the universe.”

    There is strong evidence for dark matter through its gravitational effects on ordinary matter in galaxies and clusters. These observations indicate that the universe is made up of roughly 5 percent normal matter, 25 percent dark matter and 70 percent dark energy. But to date, scientists have not directly observed dark energy or dark matter.

    “This is really the biggest embarrassment for particle physics,” Peskin says. “However much atomic matter we see in the universe, there’s five times more dark matter, and we have no idea what it is.”

    But scientists have powerful tools to try to understand some of these unknowns. Over the past several years, the number of models of dark matter has been expanding, along with the number of ways to detect it, says Tom Rizzo, a senior scientist at SLAC and head of the theory group.

    Some experiments search for direct evidence of a dark matter particle colliding with a matter particle in a detector. Others look for indirect evidence of dark matter particles interfering in other processes or hiding in the cosmic microwave background. If dark matter has the right properties, scientists could potentially create it in a particle accelerator such as the Large Hadron Collider.

    LHC

    CERN/LHC Map

    CERN LHC Tunnel

    CERN LHC particles

    Physicists are also actively hunting for signs of dark energy. It is possible to measure the properties of dark energy by observing the motion of clusters of galaxies at the largest distances that we can see in the universe.

    “Every time that we learn a new technique to observe the universe, we typically get lots of surprises,” says Marcelle Soares-Santos, a Brandeis University professor and a researcher on the Dark Energy Survey. “And we can capitalize on these new ways of observing the universe to learn more about cosmology and other sides of physics.”

    Forces at play

    Particle physicists and astrophysicists find their interests also align in the study of gravity. For particle physicists, gravity is the one basic force of nature that the Standard Model does not quite explain. Astrophysicists want to understand the important role gravity played and continues to play in the formation of the universe.

    In the Standard Model, each force has what’s called a force-carrier particle or a boson. Electromagnetism has photons. The strong force has gluons. The weak force has W and Z bosons. When particles interact through a force, they exchange these force-carriers, transferring small amounts of information called quanta, which scientists describe through quantum mechanics.

    General relativity explains how the gravitational force works on large scales: Earth pulls on our own bodies, and planetary objects pull on each other. But it is not understood how gravity is transmitted by quantum particles.

    Discovering a subatomic force-carrier particle for gravity would help explain how gravity works on small scales and inform a quantum theory of gravity that would connect general relativity and quantum mechanics.

    Compared to the other fundamental forces, gravity interacts with matter very weakly, but the strength of the interaction quickly becomes larger with higher energies. Theorists predict that at high enough energies, such as those seen in the early universe, quantum gravity effects are as strong as the other forces. Gravity played an essential role in transferring the small-scale pattern of the cosmic microwave background into the large-scale pattern of our universe today.

    “Another way that these effects can become important for gravity is if there’s some process that lasts a long time,” Silverstein says. “Even if the energies aren’t as high as they would need to be sensitive to effects like quantum gravity instantaneously.”

    Physicists are modeling gravity over lengthy time scales in an effort to reveal these effects.

    Our understanding of gravity is also key in the search for dark matter. Some scientists think that dark matter does not actually exist; they say the evidence we’ve found so far is actually just a sign that we don’t fully understand the force of gravity.

    Big ideas, tiny details

    Learning more about gravity could tell us about the dark universe, which could also reveal new insight into how structure in the universe first formed.

    Scientists are trying to “close the loop” between particle physics and the early universe, Peskin says. As scientists probe space and go back further in time, they can learn more about the rules that govern physics at high energies, which also tells us something about the smallest components of our world.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


    Advertisements
     
  • richardmitnick 12:57 pm on August 30, 2017 Permalink | Reply
    Tags: , Dark Matter, Extra dimensions, Heavy sterile neutrinos, Higgs siblings, Hunting season at the LHC, , Long-lived particles, New vector bosons, Quantum black holes, Quark substructure, Supersymmetric particles   

    From CERN: “Hunting season at the LHC” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    CERN

    10 Aug 2017
    Matthew Chalmers
    Stefania Pandolfi

    1
    Like hunters following the tracks of their prey, physicists compare real collision data with simulations of what they expect to see if a new particle is produced and decays in their detectors. (Supersymmetry simulation image: the CMS collaboration)

    With the LHC now back smashing protons together at an energy of 13 TeV, what exotic beasts do physicists hope to find in this unfamiliar corner of the natural world?

    Among the top priorities for the LHC experiments this year is the hunt for new particles suspected to lurk at the high-energy frontier: exotic beasts that do not fit within the Standard Model of particle physics and could lift the lid on an even deeper theory of nature’s basic workings.

    2
    New particles predicted by specific models of physics beyond the
    Standard Model (Image: Daniel Dominguez, with permission from Hitoshi Murayama)

    Following the discovery of the Higgs boson five years ago, which was the final missing piece of the Standard Model of particle physics, physicists have good reason to expect that new particle species lie over the horizon. Among them is the mystery of what makes up dark matter, why the Standard Model particles of matter weigh what they do and come in three families of two, and, indeed, why the Higgs boson isn’t vastly heavier than it is – that is, why it isn’t so heavy that it could have ended the evolution of the universe an instant after the Big Bang.

    Casting the net wide

    These outlandish prey are just a few of the known unknowns for physicists. To ensure that no corner of the new-physics landscape is left unturned, the LHC experiments also employ a model-independent approach to search for general features such as pairs of high-energy quarks and leptons or for unexplained sources of missing energy.

    Their most elusive quarry might not light up their detectors at all, forcing the LHC exploration teams to adopt stealth approaches, such as making ultra-precise measurements of known Standard Model processes and seeing if they diverge from predictions. While physicists are hoping for a clear shot at any new particle species – a distinctive “bump” in the data that can only be explained by the presence of a new, heavy particle – they could be faced with a mere rustling in the undergrowth or other indirect signs that something is awry. This quest is not just the preserve of all of the LHC experiments, but also of numerous other experiments at CERN that are not linked to the LHC.

    Either way, physicists exploring this uncharted territory of the high-energy frontier have to take extreme care not to get tricked by numerous Standard Model doppelgängers or be teased by inconclusive statistics. Even after an exotic new beast has been snared statistically and it seems that the LHC experiments have a discovery on their hands, so begins the task of identifying what the beast really is: a mere mutant or close relative of a species we already know? Or the first glimpse of a new subatomic kingdom?

    Ranging from the bizarre to the mind-boggling, and in no particular order, below is a summary of some of the quantum creatures that are in the LHC experimentalists’ sights this year.

    Supersymmetric particles
    What?
    For more than 40 years, physicists have been beguiled by a hypothetical symmetry of space–time called supersymmetry (SUSY), which would imply that every particle in the Standard Model has a partner called a “sparticle”. Given that these have not yet been seen, they must be heavier than the standard version.
    Why?
    Considered by many to be mathematically beautiful, SUSY can settle some of the technical problems with the Standard Model and suggests ways in which the fundamental forces may be unified. The lightest SUSY particle is also a good candidate to explain what makes up dark matter.
    How?
    SUSY could reveal itself in many ways in the LHC’s ATLAS and CMS experiments, for instance in events in which much of the energy is carried away by massive, weakly interacting sparticles. Like previous colliders, the LHC has so far found no evidence for supersymmetry, which rules out the existence of certain types of sparticles below a mass of 2 TeV.

    Higgs siblings
    What?
    The Standard Model demands just one type of Higgs boson, and so far it seems that the observed Higgs particle fits the requirements. However, many theories suggest that this standard Higgs is one of a wider family of Higgs particles with slightly different properties – SUSY predicts no less than five of them.
    Why?
    Since the Higgs boson, which gives the Standard Model particles their masses, is a fundamentally different “scalar” object compared to all other known particles, it could open the door to new physics domains.
    How?
    Exotic cousins of the Higgs have different electrical charges and other properties, especially their mass, forcing them to decay differently to the standard Higgs in ways that should be relatively easy to spot.

    New vector bosons
    What?
    At the quantum level, nature’s fundamental forces are mediated by elementary particles called vector bosons: the neutral photon for electromagnetism, and the neutral Z or charged W bosons for the weak nuclear force responsible for radioactive decay. In principle, additional vector bosons – known as W’ and Z’ – could exist, too.
    Why?
    Finding such particles would constitute the discovery of a fifth force of nature, radically changing our view of the universe and extending the structure of the Standard Model.
    How?
    Experimental signatures of new vector bosons, which presumably are heavier than the W and Z, otherwise they would have been spotted by now, range from direct production in ATLAS and CMS to more subtle signs of lepton flavour violation in LHCb.

    Extra dimensions
    What?
    The possible existence of additional dimensions of space beyond the three we know of was put forward in the late 1990s to nurse some of the Standard Model’s ills. In this picture, the entire universe could merely be a 3D “brane” floating through a higher-dimensional bulk, to which the Standard model particles are forever shackled while leaving the force of gravity to propagate freely in the bulk, or there could be additional microscopic dimensions at extremely small scales.
    Why?
    If true, it would allow physicists to study gravitons and other gravitational phenomena in the lab, as it would shift the scale of quantum gravity by many orders of magnitude, right down to the TeV scale where the LHC operates.
    How?
    The presence of extra dimensions could produce a clear missing-energy signal in the ATLAS and CMS detectors and lead to “resonances”, like notes on a guitar string, that correspond to invisible relatives of the hypothetical carrier of gravity: the graviton.

    Quantum black holes
    What?
    If extra dimensions exist, implying gravity is stronger than we thought, it is possible for very light black-holes to exist – mathematically resembling a conventional astrophysical black hole but trillions and trillions of times lighter. Such a state is predicted to evaporate more or less as soon as it formed and therefore poses no danger. After all, if such creatures are created at high energies, then they are also created all the time in collisions between cosmic rays and the upper atmosphere without doing any apparent harm.
    Why?
    The discovery of a miniature black hole would revolutionise physics and accelerate efforts to create a quantum theory of gravity that unites quantum mechanics with Einstein’s general theory of relativity.
    How?
    Miniature black holes would decay or “evaporate” instantly into other particles, revealing themselves as events containing multiple particles.

    Dark matter
    What?
    The Standard Model, while passing every test on Earth, can only account for 5% of the matter observed in the universe as a whole. It is presumed that the dark matter known to exist from astronomical observations is made of some kind of particle, perhaps a supersymmetric particle, but precisely which type is a still a mystery.
    Why?
    In addition to explaining a large fraction of the universe, the ability to study dark matter in the laboratory would open a rich and fascinating new line of experimental study.
    How?
    Dark matter interacts very weakly, if at all, via the standard forces, and would leave a characteristic missing-energy signature in the ATLAS and CMS detectors.

    Leptoquarks
    What?
    The Standard Model contains two basic types of matter: quarks, which make up protons and neutrons; and leptons, such as electrons and neutrinos. Leptoquarks are hypothetical particles that are a bit of both, allowing quarks and leptons to transform into one another.
    Why?
    Leptoquarks appear in certain extensions of the Standard Model, in particular in attempts to unify the strong, weak and electromagnetic interactions.
    How?
    Since they are expected to decay into a lepton and a quark, searches at the LHC look for characteristic bumps in the mass distributions of decay products.

    Quark substructure
    What?
    All the experimental evidence so far indicates that the six types of quarks we know of are indivisible, but history has shown us to be wrong on this front with other particles, not least the atom. Exploring matter at smaller scales, it is natural to ask: are quarks really the smallest entities, or do they possess components inside them?
    Why?
    If found, quark substructure would prove that there is a whole new layer of the subatomic world that we do not yet know about. The existence of “preons” has been postulated to give an explanation at a more fundamental level to the table of elementary particles and forces, with the aim of replicating the successful ordering of the periodic table.
    How?
    The experimental signature of the compositeness of quarks can be the detection of the decay of a quark in an excited state into ordinary quarks and gluons, which will in turn produce two streams of highly-energetic collimated particles called jets.

    Heavy sterile neutrinos
    What?
    The Standard Model involves three types of light neutrinos – electron, muon and tau neutrinos – but several puzzles, such as the very small mass of regular neutrinos, suggest that there might be additional, sterile neutrinos, much heavier than the regular ones.
    Why?
    If found, a heavy sterile neutrino can help solve the problem of matter-antimatter asymmetry in the universe. It could also be a candidate for dark matter, in addition to accounting for the small masses of the regular, non-sterile neutrinos, which cannot be otherwise explained in the framework of the Standard Model.
    How?
    The mass of sterile neutrinos is theoretically unknown, but their presence could be revealed when they “oscillate” into regular, flavoured neutrinos.

    Long-lived particles
    What?
    New particles produced in a particle collision are generally assumed to decay immediately, almost precisely at their points of origin, or to escape undetected. However, many models of new physics include heavy particles with lifetimes large enough to allow them to travel distances ranging from a few micrometres to a few hundred thousand kilometres before decaying into ordinary matter.

    Why?
    Heavy, long-lived particles can help explaining many of the unsolved questions of the Standard Model, such as the small mass of the Higgs boson, dark matter, and perhaps the imbalance of matter and antimatter in the universe.

    How?
    Long-lived particles could appear like a stream of ordinary matter spontaneously appearing out of nowhere (“displaced vertices”). Other ways to search for them include looking for a large “dE/dx”, long time of flight or tracks disappearing in the detector.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Meet CERN in a variety of places:

    Quantum Diaries
    QuantumDiaries

    Cern Courier

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New

    ALICE
    CERN ALICE New

    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    LHC

    CERN LHC Map
    CERN LHC Grand Tunnel

    CERN LHC particles

    Quantum Diaries

     
  • richardmitnick 3:03 pm on August 22, 2017 Permalink | Reply
    Tags: , Dark Matter, Newer cheaper approaches, , ,   

    From Symmetry: “Expanding the search for dark matter” 

    Symmetry Mag

    Symmetry

    08/22/17
    Lori Ann White

    At a recent meeting, scientists shared ideas for searching for dark matter on the (relative) cheap.

    Dark matter halo Image credit: Virgo consortium / A. Amblard / ESA

    Thirty-one years ago, scientists made their first attempt to find dark matter with a particle detector in a South Dakota mine.

    Since then, researchers have uncovered enough clues to think dark matter makes up approximately 26.8 percent of all the matter and energy in the universe. They think it forms a sort of gravitational scaffolding for the galaxies and galaxy clusters our telescopes do reveal, shaping the structure of our universe while remaining unseen.

    These conclusions are based on indirect evidence such as the behavior of galaxies and galaxy clusters. Direct detection experiments—ones designed to actually sense a dark matter particle pinging off the nucleus of an atom—have yet to find what they’re looking for. Nor has dark matter been seen at the Large Hadron Collider. That invisible, enigmatic material, that Greta Garbo of particle physics, still wants to be alone.

    It could be that researchers are just looking in the wrong place. Much of the search for dark matter has focused on particles called WIMPs, weakly interacting massive particles. But interest in WIMP alternatives has been growing, prompting the development of a variety of small-scale research projects to investigate some of the most promising prospects.

    In March more than 100 scientists met at the University of Maryland for “Cosmic Visions: New Ideas in Dark Matter,” a gathering to take the pulse of the post-WIMP dark matter landscape for the Department of Energy. That pulse was surprisingly strong. Organizers recently published a white paper detailing the results.

    The conference came about partly because, “it seemed a good time to get everyone together to see what each experiment was doing, where they reinforced each other and where they did something new,” says Natalia Toro, a theorist at SLAC National Accelerator Laboratory and a member of the Cosmic Visions Scientific Advisory Committee. What she and many other participants didn’t expect, Toro says, was just how many good ideas would be presented.

    Almost 50 experiments in various stages of development were presented during three days of talks, and a similar number of potential experiments were discussed.

    Some of the experiments presented would be designed to look for dark matter particles that are lighter than traditional WIMPs, or for the new fundamental forces through which such particles could interact. Others would look for oscillating forces produced by dark matter particles trillions of times lighter than the electron. Still others would look for different dark matter candidates, such as primordial black holes.

    The scientists at the workshop were surprised by how small and relatively inexpensive many of the experiments could be, says Philip Schuster, a particle theorist at SLAC National Accelerator Laboratory.

    “‘Small’ and ‘inexpensive’ depend on what technology you’re using, of course,” Schuster says. DOE is prepared to provide funding to the tune of $10 million (still a fraction of the cost of a current WIMP experiment), and many of the experiments could cost in the $1 to $2 million range.

    Several factors work together to lessen the cost. For example, advances in detector technology and quantum sensors have made technology cheaper. Then there are small detectors that can be placed at already-existing large facilities like the Heavy Photon Search, a dark-sector search at Jefferson Lab. “It’s basically a table-top detector, as opposed to CMS and ATLAS at the Large Hadron Collider, which took years to build and weigh as much as a battleship,” Schuster says.

    Experimentalist Joe Incandela of the University of California, Santa Barbara and one of the coordinators of the Cosmic Visions effort, has a simple explanation for this current explosion of ideas. “There’s a good synergy between the technology and interest in dark matter,” he says.

    Incandela says he is feeling the synergy himself. He is a former spokesperson for CMS, a battleship-class experiment in which he continues to play an active role while also developing the Light Dark Matter Experiment, which would use a high-resolution silicon-based calorimeter that he originally helped develop for CMS to search for an alternative to WIMPs.

    “It occurred to me that this calorimeter technology could very useful for low-mass dark matter searches,” he says. “My hope is that, starting soon, and spanning roughly five years, the funding—and not very much is needed—will be available to support experiments that can cover a lot more of the landscape where dark matter may be hiding. It’s very exciting.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 4:41 pm on August 4, 2017 Permalink | Reply
    Tags: , , , CMU-Carnegie Mellon University, , Dark Matter, , Scott Dodelson   

    From CMU: “Scott Dodelson Appointed Head of Department of Physics” 

    Carnegie Mellon University logo
    Carnegie Mellon University

    [It is rare that I would post about such an appointment. But Scott Dodelson is a rare bird.]
    [This post is dedicated to J.L.T. Jack, keep your eye on this guy and CMU.]

    August 3, 2017
    Jocelyn Duffy

    1
    Scott Dodelson

    Renowned physicist Scott Dodelson has been named the head of the Department of Physics in Carnegie Mellon University’s Mellon College of Science.

    Dodelson conducts research at the interface between particle physics and cosmology, examining the phenomena of dark energy, dark matter, inflation and cosmological neutrinos.

    He is the co-chair of the Science Committee for the Dark Energy Survey (DES), an international collaboration that aims to map hundreds of millions of galaxies, detect thousands of supernovae and find patterns of cosmic structure in an attempt to reveal the nature of dark energy.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    On Aug. 3, the DES released results that measured the structure of the universe to the highest level of precision yet.

    Dodelson also works with the South Pole Telescope and the Large Synoptic Survey Telescope (LSST).

    South Pole Telescope

    The South Pole Telescope studies the Cosmic Microwave Background to gain a better understanding of inflation, dark energy and neutrinos. The LSST, which is currently being built in Chile, will survey the sky for a decade, creating an enormous data set that will help scientists determine the properties of dark energy and dark matter and the composition and history of our solar system.

    LSST


    LSST Camera, built at SLAC



    LSST telescope, currently under construction at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    Dodelson was attracted to CMU in part by the physics department’s varied areas of strength and the leadership role the department’s McWilliams Center for Cosmology and its faculty play in a number of large, international cosmological surveys, including LSST and the Sloan Digital Sky Survey.

    “Within the McWilliams Center, I found kindred spirits in the faculty who are leading scientific projects aimed at understanding the universe, but I was equally attracted to the department’s strong groups in biological physics, condensed matter and nuclear and particle physics,” said Dodelson. “I’m excited to learn about these diverse fields and connect with other departments throughout the university.”

    Under Dodelson’s leadership, the physics department will partner with other departments within the Mellon College of Science through a new theory center and continue to collaborate with colleagues in statistics, computer science and engineering. Dodelson also hopes to increase the department’s partnerships with other universities and research initiatives worldwide and bring physics to the community through outreach programs.

    “I was drawn by the university’s enthusiasm for foundational research,” Dodelson said. “The physics department will strive to bring this excitement to students, alumni and the broader community.”

    Dodelson comes to Carnegie Mellon from the Fermi National Accelerator Laboratory (Fermilab), where he was a distinguished scientist, and the University of Chicago where he was a professor in the Department of Astronomy and Astrophysics and Kavli Institute for Cosmological Physics. While at Fermilab, Dodelson served as head of the Theoretical Astrophysics Group and co-founder and interim director of the Center for Particle Astrophysics.

    Dodelson earned a joint B.A./B.S. degree in applied physics and a Ph.D. in theoretical physics from Columbia University. He completed a post-doctoral fellowship at Harvard University.

    Dodelson will assume the position of department head from Stephen Garoff who has served as head since 2013.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Carnegie Mellon Campus

    Carnegie Mellon University (CMU) is a global research university with more than 12,000 students, 95,000 alumni, and 5,000 faculty and staff.
    CMU has been a birthplace of innovation since its founding in 1900.
    Today, we are a global leader bringing groundbreaking ideas to market and creating successful startup businesses.
    Our award-winning faculty members are renowned for working closely with students to solve major scientific, technological and societal challenges. We put a strong emphasis on creating things—from art to robots. Our students are recruited by some of the world’s most innovative companies.
    We have campuses in Pittsburgh, Qatar and Silicon Valley, and degree-granting programs around the world, including Africa, Asia, Australia, Europe and Latin America.

     
  • richardmitnick 11:43 am on July 31, 2017 Permalink | Reply
    Tags: , Dark Matter, , , , , ,   

    From FNAL: “ICARUS arrives at Fermilab” 

    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 31, 2017
    Leah Hesla

    1
    The ICARUS detector pulls in to the Fermilab site on July 26. Photo: Reidar Hahn

    After six weeks’ passage across the ocean, up rivers and on the road, the newest member of Fermilab’s family of neutrino detectors has arrived.

    The 65-foot-long ICARUS particle detector pulled into Fermilab aboard two semi-trucks on July 26 to an excited gathering who welcomed the detector, which has spent the last three years at the European laboratory CERN, to its new home.

    “We’ve waited a long time for ICARUS to get here, so it’s thrilling to finally see this giant, exquisite detector at Fermilab,” said scientist Peter Wilson, who leads the Fermilab Short-Baseline Neutrino Program. “We’re looking forward to getting it online and operational.”

    The ICARUS detector will be instrumental in helping an international team of scientists at the Department of Energy’s Fermilab get a bead on the slippery neutrino, the most ubiquitous yet least understood matter particle in the universe. The neutrino passes through outer space, metal, you and me without leaving a trace. Scientists have observed three types of neutrino. As it travels, it continually slips in and out of its various identities.

    Previous neutrino experiments have seen hints of yet another type, and ICARUS will hunt for evidence of this unconfirmed fourth. If found, the fourth neutrino could provide a new way of modeling dark matter, another of nature’s mysterious phenomena, one that makes up a whopping 23 percent of the universe. (Ordinary matter makes up only 4 percent of the universe.) A fourth neutrino would also change scientists’ fundamental picture of how the universe works.

    Fermilab is ICARUS detector’s second home. From 2010 to 2014, the Italian National Institute for Nuclear Physics’ Gran Sasso laboratory built and operated ICARUS to study neutrinos using a neutrino beam sent straight through the Earth’s mantle from CERN in Switzerland, about 600 miles away.

    INFN Gran Sasso ICARUS, since moved to FNAL

    Gran Sasso LABORATORI NAZIONALI del GRAN SASSO, located in the Abruzzo region of central Italy

    ICARUS’ lead scientist, Nobel laureate Carlo Rubbia, innovated the use of liquid argon to detect neutrinos.

    ICARUS is the largest liquid-argon neutrino detector in the world. Its great mass — it will be filled with 760 tons of liquid argon — gives neutrinos, always reluctant to interact with anything, plenty of opportunities to come into contact with an argon nucleus. The charged particles resulting from the interaction create tracks that scientists can study to learn more about the neutrino that triggered them.

    In 2014, after the ICARUS experiment wrapped up in Italy, its detector was delivered to CERN. Since then, CERN and INFN have been improving the detector, refurbishing it for Fermilab’s mission. CERN completed the project in May and sent ICARUS on its trans-Atlantic voyage in June.

    “This is really exciting — to have the world’s original, large-scale liquid-argon neutrino detector at Fermilab,” said Cat James, senior scientist on Fermilab’s Short-Baseline Neutrino Program.

    Fermilab’s Short-Baseline Neutrino Program involves three neutrino detectors. ICARUS is one, and now that it has safely landed at Fermilab, it will be installed as part of the program. Another detector, MicroBooNE, has been in operation since 2015.

    FNAL/MicrobooNE

    The construction of the third, called the Short-Baseline Near Detector, is in progress.

    FNAL Short-Baseline Near Detector under construction

    All three use liquid argon to detect the elusive neutrino.

    The development and use of liquid-argon technology for the three detectors will be further wielded for Fermilab’s new flagship experiment, the Deep Underground Neutrino Experiment.

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


    FNAL DUNE Argon tank at SURF


    Surf-Dune/LBNF Caverns at Sanford



    SURF building in Lead SD USA

    Fermilab and South Dakota’s Sanford Underground Research Laboratory broke ground on the new experiment on July 21.

    “We’re really looking forward to working with our international partners as we get ICARUS ready for first beam,” James said.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    FNAL Icon
    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 1:32 pm on July 25, 2017 Permalink | Reply
    Tags: , Dark Matter, , Hidden-sector particles, MiniBooNE, , ,   

    From FNAL: “The MiniBooNE search for dark matter” 

    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 18, 2017
    Ranjan Dharmapalan
    Tyler Thornton

    FNAL/MiniBooNE

    1
    This schematic shows the experimental setup for the dark matter search. Protons (blue arrow on the left) generated by the Fermilab accelerator chain strike a thick steel block. This interaction produces secondary particles, some of which are absorbed by the block. Others, including photons and perhaps dark-sector photons, symbolized by V, are unaffected. These dark photons decay into dark matter, shown as χ, and travel to the MiniBooNE detector, depicted as the sphere on the right.

    Particle physicists are in a quandary. On one hand, the Standard Model accurately describes most of the known particles and forces of interaction between them.

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    On the other, we know that the Standard Model accounts for less than 5 percent of the universe. About 26 percent of the universe is composed of mysterious dark matter, and the remaining 68 percent of even more mysterious dark energy.

    Some theorists speculate that dark matter particles could belong to a “hidden sector” and that there may be portals to this hidden sector from the Standard Model. The portals allow hidden-sector particles to trickle into Standard Model interactions. A large sensitive particle detector, placed in an intense particle beam and equipped with a mechanism to suppress the Standard Model interactions, could unveil these new particles.

    Fermilab is home to a number of proton beams and large, extremely sensitive detectors, initially built to detect neutrinos. These devices, such as the MiniBooNE detector, are ideal places to search for hidden-sector particles.

    In 2012, the MiniBooNE-DM collaboration teamed up with theorists who proposed new ways to search for dark matter particles. One of these proposals [FNAL PAC Oct 15 2012] involved the reconfiguration of the existing neutrino experiment. This was a pioneering effort that involved close coordination between the experimentalists, accelerator scientists, beam alignment experts and numerous technicians.

    2
    Results of this MiniBooNE-DM search for dark matter scattering off of nucleons. The plot shows the confidence limits and sensitivities with 1, 2σ errors resulting from this analysis compared to other experimental results, as a function of Y (a parameter describing the dark photon mass, dark matter mass and the couplings to the Standard Model) and Mχ (the dark matter mass). For details see the Physical Review Letters paper.

    For the neutrino experiment, the 8-GeV proton beam from the Fermilab Booster hit a beryllium target to produce a secondary beam of charged particles that decayed further downstream, in a decay pipe, into neutrinos. MiniBooNE ran in this mode for about a decade to measure neutrino oscillations and interactions.

    In the dark matter search mode, however, the proton beam was steered past the beryllium target. The beam instead struck a thick steel block at the end of the decay pipe. The resulting charged secondary particles (mostly particles called pions) are absorbed in the steel block, reducing the number of subsequent neutrinos, while the neutral secondary particles remained unaffected. The photons resulting from the decay of neutral pions may have transformed into hidden-sector photons that in turn might have decayed into dark matter, which would travel to the MiniBooNE detector 450 meters away. The experiment ran in this mode for nine months for a dedicated dark matter search.

    Using the previous 10 years’ worth of data as a baseline, MiniBooNE-DM looked for scattered protons and neutrons in the detector. If they found more scattered protons or neutrons than predicted, the excess could indicate a new particle, maybe dark matter, being produced in the steel block. Scientists analyzed multiple types of neutrino interactions at the same time, reducing the error on the signal data set by more than half.

    Analysts concluded that the data was consistent with the Standard Model prediction, enabling the experimenters to set a limit on a specific model of dark matter, called vector portal dark matter. To set the limit, scientists developed a detailed simulation that estimated the predicted proton or neutron response in the detector from scattered dark matter particles. The new limit extends from the low-mass edge of direct-detection experiments down to masses about 1,000 times smaller. Additionally, the result rules out this particular model as a description of the anomalous behavior of the muon seen in the Muon g-2 experiment at Brookhaven, which was one of the goals of the MiniBooNE-DM proposal. Incidentally, researchers at Fermilab will make a more precise measurement of the muon — and verify the Brookhaven result — in an experiment that started up this year.

    This result from MiniBooNE, a dedicated proton beam dump search for dark matter, was published in Physical Review Letters and was highlighted as an “Editor’s suggestion.”

    What’s next? The experiment will continue to analyze the collected data set. It is possible that the dark matter or hidden-sector particles may prefer to scatter off of the lepton family of particles, which includes electrons, rather than off of quarks, which are the constituent of protons and neutrons. Different interaction channels probe different possibilities.

    If the portals to the hidden sector are narrow — that is, if they are weakly coupled — researchers will need to collect more data or implement new ideas to suppress the Standard Model interactions.

    The first results from MiniBooNE-DM show that Fermilab could be at the forefront of searching for hidden-sector particles. Upcoming experiments in Fermilab’s Short-Baseline Neutrino program will use higher-resolution detectors — specifically, liquid-argon time projection chamber technology — expanding the search regions and possibly leading to discovery.

    Ranjan Dharmapalan is a postdoc at Argonne National Laboratory. Tyler Thornton is a graduate student at Indiana University Bloomington.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    FNAL Icon
    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 10:22 am on July 23, 2017 Permalink | Reply
    Tags: , , , , , , , Dark Matter, FDM-Fuzzy Dark Matter, Lyman-alpha forest   

    From Astro Watch: “Flashes of Light on the Dark Matter” 

    Astro Watch bloc

    Astro Watch

    July 23, 2017
    No writer credit found

    1

    A web that passes through infinite intergalactic spaces, a dense cosmic forest illuminated by very distant lights and a huge enigma to solve. These are the picturesque ingredients of a scientific research – carried out by an international team composed of researchers from the International School for Adavnced Studies (SISSA) and the Abdus Salam International Center for Theoretical Physics (ICTP) in Trieste, the Institute of Astronomy of Cambridge and the University of Washington – that adds an important element for understanding one of the fundamental components of our Universe: the dark matter.

    In order to study its properties, scientists analyzed the interaction of the “cosmic web” – a network of filaments made up of gas and dark matter present in the whole Universe – with the light coming from very distant quasars and galaxies. Photons interacting with the hydrogen of the cosmic filaments create many absorption lines defined “Lyman-alpha forest”. This microscopic interaction succeeds in revealing several important properties of the dark matter at cosmological distances. The results further support the theory of Cold Dark Matter, which is composed of particles that move very slowly. Moreover, for the first time, they highlight the incompatibility with another model, i.e. the Fuzzy Dark Matter, for which dark matter particles have larger velocities. The research was carried out through simulations performed on international parallel supercomputers and has recently been published in Physical Review Letters.

    Although constituting an important part of our cosmos, the dark matter is not directly observable, it does not emit electromagnetic radiation and it is visible only through gravitational effects. Besides, its nature remains a deep mystery. The theories that try to explore this aspect are various. In this research, scientists investigated two of them: the so-called Cold Dark Matter, considered a paradigm of modern cosmology, and an alternative model called Fuzzy Dark Matter (FDM), in which the dark matter is deemed composed of ultralight bosons provided with a non-negligible pressure at small scales. To carry out their investigations, scientists examined the cosmic web by analyzing the so-called Lyman-alpha forest. The Lyman-alpha forest consists of a series of absorption lines produced by the light coming from very distant and extremely luminous sources, that passes through the intergalactic space along its way toward the earth’s telescopes. The atomic interaction of photons with the hydrogen present in the cosmic filaments is used to study the properties of the cosmos and of the dark matter at enormous distances.

    Through simulations carried out with supercomputers, researchers reproduced the interaction of the light with the cosmic web. Thus they were able to infer some of the characteristics of the particles that compose the dark matter. More in particular, evidence showed for the first time that the mass of the particles, which allegedly compose the dark matter according to the FDM model, is not consistent with the Lyman-alpha Forest observed by the Keck telescope (Hawaii, US) and the Very Large Telescope (European Southern Observatory, Chile).


    Keck Observatory, Maunakea, Hawaii, USA

    ESO/VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

    Basically, the study seems not to confirm the theory of the Fuzzy Dark Matter. The data, instead, support the scenario envisaged by the model of the Cold Dark Matter.

    The results obtained – scientists say – are important as they allow to build new theoretical models for describing the dark matter and new hypotheses on the characteristics of the cosmos. Moreover, these results can provide useful indications for the realization of experiments in laboratories and can guide observational efforts aimed at making progress on this fascinating scientific theme.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 1:16 pm on July 12, 2017 Permalink | Reply
    Tags: , Dark Matter, HAYSTAC - Haloscope at Yale Sensitive To Axion Cold Dark Matter, , ,   

    From Yale: “Needle in a HAYSTAC” 

    Yale University bloc

    Yale University

    July 5, 2017
    Elizabeth Ruddy

    1
    No image caption or credit.

    Imagine searching for a needle in a haystack. The needle weighs about 100 billion times less than an electron and has no charge. It acts like a wave rather than a particle, and the haystack is the size of our universe. Needles like this may exist in the tens of trillions in every cubic centimeter of space—the trick is proving that they’re there.

    That is the mission of the HAYSTAC Project at Yale, which stands for the Haloscope at Yale Sensitive To Axion Cold Dark Matter. HAYSTAC is a collaboration between Yale University, University of California, Berkeley and University of Colorado, Boulder. The project is based here in the Wright Laboratory, lead by Professor Steve Lamoreaux and a team of Yale scientists and graduate students. The scientists began their project about five years ago and released their first results this past February in The Physics Review Letters. The first author was Yale graduate student Ben Brubaker.

    “The goals of the experiment are to detect dark matter, or failing that, to at least rule out some possible models for what dark matter is,” explained Brubaker. “In simplest terms, dark matter started out as an astrophysics question: that is, there is more mass in the universe than can be accounted for by the mass we can see [through] all the wavelengths we can detect: visible light, radio waves, ultraviolet.” Dark matter is the “invisible” matter.

    The HAYSTAC project is dedicated specifically to the detection of the axion, a subatomic particle that was proposed in 1983 as a likely candidate for dark matter. Like the aforementioned needle, axions are theorized to have almost miniscule mass, no charge, and no spin. Based on the gravitational movement of stars and galaxies, we know that 80 percent of the matter in our universe is dark matter, but axions interact with other matter so weakly they become almost impossible to detect. Because they are so light, they have very little energy and behave more like waves than particles. As a result, the scientists must employ an unusual identification strategy to find them.

    2
    The HAYSTAC axion detector probes the universe for axions, a potential candidate for dark matter. No image credit.

    The HAYSTAC detection device essentially produces a magnetic field that converts the axions to photons. The frequency of oscillation of the photons is determined by the mass of the axion. Therefore, when the detector is tuned in to one specific frequency at a time, it can amplify these oscillations to make them detectable.

    “Our detector is in essence a tunable radio receiver, and we painstakingly tune the receiving frequency looking for an increase in noise. It is like driving through a desert looking for a station on the car radio: you tune slowly in hopes of finding something,” said Professor Lamoreaux, the head of the project.

    In the February report, the team demonstrated its recent breakthroughs in design: they had achieved sufficient sensitivity to test out much higher frequencies in the potential mass range than ever before. By incorporating technology from other fields such as quantum electronics, Lamoreaux and his colleagues have made the detector colder and quieter than any of its contemporaries, eliminating as much of the background noise as possible. According to Brubaker, the device is kept at about 0.1 degree Celsius above absolute zero, the unattainable temperature at which atoms physically stop moving. Freezing temperatures are critical for sensitivity because a major source of noise is thermal radiation: photons being shed by matter and interfering with the detection of axions.

    According to Professor Lamoreaux, their detector is currently the most sensitive radio receiver ever built. “Imagine a match lit on the surface of the Moon…the rate of energy entering the pupil of your eye, when the match is viewed from the Earth, is about the level of sensitivity we achieve.”

    The size of the detector scales inversely with the mass range being tested, so the Wright Lab instrument will only be able to search a small portion of the wide range of possible dark matter masses. However, the team has proven they have a design with the sensitivity capability necessary to perform these sweeps. Their design is a pioneering model for the future.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Yale University Campus

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
  • richardmitnick 1:18 pm on July 6, 2017 Permalink | Reply
    Tags: , , , Chasing the invisible, Dark Matter, , ,   

    From ATLAS: “Chasing the invisible” 

    CERN ATLAS Higgs Event

    CERN/ATLAS
    ATLAS

    6th July 2017
    ATLAS Collaboration

    1
    Figure 1: The second highest ETmiss monojet event in the 2016 ATLAS data. A jet with pT of 1707 GeV is indicated by the green and yellow bars corresponding to the energy deposition in the electromagnetic and hadronic calorimeters respectively. The ETmiss of 1735 GeV is shown as the white dashed line in the opposite side of the detector. No additional jets with pT above 30 GeV are found. (Image: ATLAS Collaboration/CERN)

    Cosmological and astrophysical observations based on gravitational interactions indicate that the matter described by the Standard Model of particle physics constitutes only a small fraction of the entire known Universe. These observations infer the existence of Dark Matter, which, if of particle nature, would have to be beyond the Standard Model.

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    Although the existence of Dark Matter is well-established, its nature and properties still remain one of the greatest unsolved puzzles of fundamental physics. Excellent candidates for Dark Matter particles are weakly interacting massive particles (WIMPs). These “invisible” particles cannot be detected directly by collision experiments.

    At the LHC, most collisions of protons produce sprays of energetic particles that bundle together into so-called “jets”. Momentum conservation requires that if particles are reconstructed in one part of the detector there have to be recoiling particles in the opposite direction. However, if WIMPs are produced they will leave no trace in the detector, causing a momentum imbalance called “missing transverse momentum” (ETmiss). However, a pair of WIMPs can be produced together with a quark or gluon that is radiated from an incoming parton (a generic constituent of the proton) producing a jet which allows to tag this kind of events.

    The jets+ETmiss search looks at final states where a highly energetic jet is produced in association with large ETmiss. Many beyond the Standard Model theories can be probed by looking for an excess of events with large missing transverse momentum compared to the Standard Model expectation. Among those theories, Supersymmetry and models which foresee the existence of Large Extra Spatial Dimensions (LED), predict additional particles that are invisible to collider experiments. These theories could give an elegant explanation to several anomalies still unsolved in the Standard Model.

    2
    Figure 2: Missing transverse momentum distribution after the jets+ETmiss selection in data and in the Standard Model predictions. The different background processes are shown in different colors. The expected spectra of LED, Supersymmetric and WIMP scenarios are also illustrated with dashed lines. (Image: ATLAS Collaboration/CERN)

    The combination of data-driven techniques and high-precision theoretical calculations has allowed ATLAS to predict the main Standard Model background processes with great precision. The shape of the ETmiss spectrum is used to increase the discovery potential of the analysis and increase the discrimination power between signals and background.

    The figure shows the missing transverse momentum spectrum compared to the measurement with the Standard Model expectation. Since no significant excess is observed, the level of agreement between data and the prediction is translated into limits on unknown parameters of the Dark Matter, Supersymmetry and LED models.

    In the WIMP scenario, the latest analysis using data collected in 2015 and 2016 in a specific interaction model are able to exclude Dark Matter masses up to 440 GeV and interaction mediators up to 1.55 TeV. Under the considered model, these represent competitive results when compared with other experiments using different detection approaches.

    Over the next two years the LHC aims to increase the data available by a factor of three. This will be a unique opportunity for ATLAS to investigate the energy frontier and the jets+ETmiss channel will continue to hold the potential to profoundly revise our understanding of the universe.

    Links:

    Search for dark matter and other new phenomena in events with an energetic jet and large missing transverse momentum using the ATLAS detector (ATLAS-CONF-2017-060): link coming soon
    EPS 2017 presentation by Shin-Shan Yu: Dark matter searches at colliders
    See also the full lists of ATLAS Conference Notes and ATLAS Physics Papers.

    See the full article here .

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition


    CERN Courier

    QuantumDiaries


    Quantum Diaries

     
  • richardmitnick 5:53 pm on July 2, 2017 Permalink | Reply
    Tags: , , , , Dark Matter, ,   

    From Waterloo: ‘Waterloo researchers capture first image of a dark matter web that connects galaxies” 

    U Waterloo bloc

    University of Waterloo

    April 12, 2017 [Missed this one.]
    Media Contact:
    Matthew Grant
    matthew.grant@uwaterloo.ca
    University of Waterloo
    519-888-4451
    http://www.uwaterloo.ca/news
    @uWaterlooNews

    1
    Dark matter filaments (shown in red) bridge the space between galaxies (shown in white) on this false colour map. No image credit.

    Researchers at the University of Waterloo have been able to capture the first composite image of a dark matter bridge that connects galaxies together.

    The composite image, which combines a number of individual images, confirms predictions that galaxies across the universe are tied together through a cosmic web connected by dark matter that has until now remained unobservable.

    Dark matter, a mysterious substance that comprises around 25 per cent of the universe, doesn’t shine, absorb or reflect light. It has traditionally been largely undetectable, except through gravity.

    “For decades, researchers have been predicting the existence of dark-matter filaments between galaxies that act like a web-like superstructure connecting galaxies together,” said Mike Hudson, a professor of astronomy at the University of Waterloo. “This image moves us beyond predictions to something we can see and measure.”

    As part of their research, Hudson and co-author Seth Epps, a former master’s student at the University of Waterloo, used a technique called weak gravitational lensing.

    It’s an effect that causes the images of distant galaxies to warp slightly under the influence of an unseen mass such as a planet, a black hole, or in this case, dark matter. The effect was measured in images from a multi-year sky survey at the Canada-France-Hawaii Telescope.


    CFHT Telescope, Mauna Kea, Hawaii, USA

    They combined lensing images from more than 23,000 galaxy pairs located 4.5 billion light-years away to create a composite image or map that shows the presence of dark matter between the two galaxies. Results show the dark matter filament bridge is strongest between systems less than 40 million light-years apart.

    “By using this technique, we’re not only to able to see that these dark matter filaments in the universe exist, we’re able to see the extent to which these filaments connect galaxies together,” said Epps.

    Hudson and Epps’ research appears in the Monthly Notices of the Royal Astronomical Society.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    U Waterloo campus

    In just half a century, the University of Waterloo, located at the heart of Canada’s technology hub, has become a leading comprehensive university with nearly 36,000 full- and part-time students in undergraduate and graduate programs.

    Consistently ranked Canada’s most innovative university, Waterloo is home to advanced research and teaching in science and engineering, mathematics and computer science, health, environment, arts and social sciences. From quantum computing and nanotechnology to clinical psychology and health sciences research, Waterloo brings ideas and brilliant minds together, inspiring innovations with real impact today and in the future.

    As home to the world’s largest post-secondary co-operative education program, Waterloo embraces its connections to the world and encourages enterprising partnerships in learning, research, and commercialization. With campuses and education centres on four continents, and academic partnerships spanning the globe, Waterloo is shaping the future of the planet.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: