World's most sensitive dark matter detector comes up empty

Scientists working a mile underground in South Dakota's Black Hills report a null result in their most recent efforts to detect elusive dark matter.

|
Matthew Kapust. Copyright © South Dakota Science and Technology Authority
An artist illustration showing the view from inside the Large Underground Xenon (LUX) dark matter detector buried deep below the Black Hills of South Dakota. Image released Oct. 30, 2013.

A new experiment buried deep underground has proven itself to be the most sensitive dark-matter detector ever built. But the first results from the high-tech instrument have turned up empty in its search for elusive dark matter, scientists announced today (Oct. 30).

Housed 1 mile (1.6 kilometers) underground in the Black Hills of South Dakota, the Large Underground Xenon (LUX) experiment's sensitivity makes it better at seeking out dark matter than any other detectors built for that purpose, LUX officials said. Although the powerful dark matter detector has just completed its first run, LUX has not yet found conclusive evidence of the elusive substance.

"The universe's mysterious dark sector presents us with two of the most thrilling challenges in all of physics," Saul Perlmutter, of the Lawrence Berkeley National Laboratory and a winner of the 2011 Nobel Prize in physics, said in a statement. "We call it the dark sector precisely because we don't know what accounts for most of the energy and mass in the universe. Dark energy is one challenge, and as for the other, the LUX experiment's first data now take the lead in the hunt for the dark-matter component of the dark sector." [Photos: Dark Matter Throughout The Universe]

Scientists think that dark matter makes up the majority of the matter in the universe; however, it cannot be seen or touched. Astronomers detect dark matter because they have seen its gravitational pull on galaxies and stars.

By running experiments like LUX far underground, scientists hope to shield the dark-matter detector from everything butWIMPs — weakly interacting massive particles that are thought to be the leading candidates for the particles that make up dark matter.

"LUX is the quietest place verified in the world," Rick Gaitskell, a Brown University physicist, said during a seminar today (Oct. 30). "That's how far we've had to go in order to be in a position to look for these WIMPs." 

LUX is particularly adept at searching for low-mass WIMPs, which are predicted by some theoretical physics models.WIMPS are extremely difficult to find because they rarely interact with ordinary matter, except through gravity, LUX officials said.

Scientists think that WIMPs can be both low-mass and high-mass, and LUX has an enhanced sensitivity to low-mass WIMPs. The dark-matter detector recently completed its first data-collecting research run.

Through the course of the approximately three-month WIMP search, scientists did not find signals of WIMPs, although previous experiments with other detectors predicted that they would.

"Three candidate WIMP events recently reported in ultracold silicon detectors, however, would have produced more than 1,600 events in LUX's much larger detector, or one every 80 minutes in the recent run," LUX officials said in a statement. "No such signals were seen."

LUX houses a 6-foot-tall (1.8 meters) titanium tank filled with liquid xenon and cooled to minus 150 degrees Fahrenheit (minus 101 degrees Celsius). The xenon tank is surrounded by rock and a tank of water.

If a WIMP comes into contact with a xenon atom, it will emit light and electrons. The electrons are pulled upward and release more photons. By recording both the photons at the collision point and at the top of the tank, the detector is able to pinpoint the locations of the photon signals and measure their brightness.

Follow Miriam Kramer @mirikramer and Google+. Follow us @SpacedotcomFacebook and Google+. Original article on SPACE.com.

Copyright 2013 SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to World's most sensitive dark matter detector comes up empty
Read this article in
https://www.csmonitor.com/Science/2013/1030/World-s-most-sensitive-dark-matter-detector-comes-up-empty
QR Code to Subscription page
Start your subscription today
https://www.csmonitor.com/subscribe