Dark Matter Search Enters Round 2
Three experiments will begin upgrades that could help them corner the particles responsible for the universe’s missing mass

Jul 28, 2014 |By Clara Moskowitz

Dark matter scientists are doubling down on efforts to catch the elusive particles thought to constitute most of the matter in the universe. These theorized particles make themselves felt through gravity: They appear to tug on the normal matter throughout the universe but they otherwise can’t be seen or touched. Experiments aiming to observe the rare occasions when dark matter particles interact with normal atoms have been operating for decades without success and have already ruled out many of the most basic explanations for dark matter. Rather than give up the search, however, three of the largest experiments recently won approval to make big upgrades, potentially allowing them to reach the sensitivities needed to finally pin down these cagey missing particles.

The three experiments moving forward—the Super Cryogenic Dark Matter Search–SNOLAB (SuperCDMS); LZ Dark Matter Experiment, or LUX–ZEPLIN, (LZ); and the Axion Dark Matter eXperiment (ADMX–Gen2)—are among the largest and longest-running projects in the field. They beat out around 20 other bids submitted to the U.S. Department of Energy and the National Science Foundation, which jointly announced their selections for the next-generation dark matter experiments last week. Both SuperCDMS and LZ will search for dark matter candidate particles called weakly interacting massive particles (WIMPs) whereas ADMX-Gen2 will look for alternative candidates called axions.

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