Broadcaster Press 03 February 25, 2014 www.broadcasteronline.com Professor’s research focuses on WIMPS By Travis Gulbrandson travis.gulbrandson@plai ntalk.net Scientists have long been searching for answers about what makes up most of the universe. Through continuing searches for weakly interacting massive particles (WIMPs), they may be closer than ever before. Dr. Richard Schnee, assistant professor of physics at Syracuse University, spoke at the University of South Dakota Thursday, Feb. 20, about WIMP-related research, its past and its future. Schnee said the search for WIMPs is motivated by observations of cosmology and astrophysics that are “all consistent with a picture that the universe is geometrically flat, and that most of the energy density of the universe is in some cosmological constant, or dark energy.” Additionally, about 30 percent of the universe’s energy density is some kind of “dark matter,” he said. “It’s non-baryonic, it’s not made up of the same things that make up you, me or the rest of the earth,” Schnee said. “This nonbaryonic, cold dark matter can’t be any particle that we know about, so therefore, this is the best experimental evidence that the standard model of particle physics is incomplete.” WIMPs are arguably the best candidates for what makes up dark matter, he said. “There are a couple different ways you can actually end up with WIMPS making up this amount of the energy density of the universe,” Schnee said. “First, if the WIMPS are produced thermally in the early universe, when the universe is a soup of particles, then if the particles are weaklyinteracting, as the universe expands, they’ll stop being able to find each other so you’ll end up with some of these particles left over. “In addition to that, if a WIMP is relatively light … then WIMPS will have about the same abundance as the baryons. So, the WIMPS could be related to whatever caused an asymmetry between matter and anti-matter in the universe,” he said. There are three ways to detect WIMPs: Using colliders, indirect detection and direct detection. Each of these methods uses interactions shown schematically between dark matter and standard particles, Schnee said. If there are enough dark matter particles in an astrophysical body, they might interact with each other and annihilate, and then be detected with highpowered telescopes or satellites, he said. “The three methods of detecting WIMPS are complementary to each other,” Schnee said. “It’s possible for any one of these three techniques to succeed while the other ones don’t succeed. There are some models that are easier to detect with colliders, and others with direct or indirect detection.” In addition, more information can be acquired if WIMPs are detected with more than one of these methods simultaneously. “It’s only be detecting WIMPs by several of these methods that we can learn all we would like to know about particle physics, astrophysics and cosmology,” Schnee said. For example, you can learn a lot of you detect a WIMP in a collider, but it’s impossible to tell if the WIMP is stable, and therefore the dark matter in the universe. “It’s only by also detecting a particle of the same mass using direct detection that we know that same particle is the same dark matter in our galaxy,” Schnee said. There are about 20 such experiments trying to detect WIMPs that are either running or about to run, including one at the Sanford Underground Research Facility at Homestake. Another of these experiments is taking place at the Soudan Mine in northern Minnesota, SuperCDMS (cryogenic dark matter search). “Direct detection has unique capabilities for answering fundamental questions about both astrophysics and particle physics,” Schnee said. “It is possible that CDMS … might already have detected WIMP interactions, but I would bet against it at this point. … “In the long range, CDMS technology provides a unique discovery potential for lowmass WIMPs, as well as a low-risk way forward for higher-mass WIMPs, and radon reduction is a critical part for this sensitivity for low-mass WIMPs,” he said. Schnee said results from the SuperCDMS experiment will be available in the spring. Waterproof Boots/Shoes Over 20 Styles To Choose From And On Sale! Keep those toes dry! Junior Iverson will be 90 on March 4th! FREE Socks With Boots! Boston 3rd • Yankton • to Boots Shoes 665-9092 312 W. 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