A Super-Sensitive Dark Matter Detector Just Booted Up

The LUX-ZEPLIN (LZ) experiment crew has introduced the outcomes from its first scientific run right now; the experiment is the world’s most delicate darkish matter detector, and although it didn’t discover any darkish matter on this first spherical, the crew confirmed that the experiment is working as anticipated.

The LZ experiment detector is made up nested tanks of liquid xenon, every 1.5 meters tall and 1.5 meters vast, buried underneath North Dakota. The thought is {that a} darkish matter particle whizzing by area will ultimately bounce off one of many xenon atoms, knocking free electrons in a flash that’s recorded by the experiment. The tank is buried a couple of mile beneath Earth’s floor to attenuate the quantity of background noise. Today’s announcement comes after 60 stay days of knowledge assortment that spanned December 25 to May 12.

“We’re looking for very, very low-energy recoils by the standards of particle physics. It’s a very, very rare process, if it’s visible at all,” mentioned Hugh Lippincott, a physicist at UC Santa Barbara and a member of the LZ crew, in a press convention right now. “You can shoot a dark matter particle through 10 million light-years of lead and expect only one interaction at the end of that light-year.”

Dark matter is the catch-all time period for the unknown stuff that seems to make up about 27% of the universe. It rarely interacts with peculiar matter, therefore its “darkness” to us. But we all know it’s on the market as a result of, whereas by no means instantly detected, it has gravitational results that may be seen on cosmic scales. (NASA breaks down the idea fairly properly here.)

There are many candidates for darkish matter. One is the WIMP, or a Weakly Interacting Massive Particle. Unlike different darkish matter hypotheses like axions or darkish photons, that are so small and diffuse that they could behave extra like waves, WIMPs would have mass however rarely work together with peculiar matter. So to detect them, you want a tool that just about mutes all different physics occurring.

LZ is tremendous delicate, which makes it good for recognizing such fleeting and rare interactions. The experiment is 30 occasions bigger and 100 occasions extra delicate than its predecessor, the Large Underground Xenon experiment, in response to a Sanford Underground Research Facility release. LZ is “effectively an onion” Lippincott mentioned, with every layer of the experiment insulating in opposition to noise that would obscure a possible WIMP interplay.

“The collaboration worked well together to calibrate and to understand the detector response,” mentioned Aaron Manalaysay, a physicist at Berkeley Laboratory and a member of the LZ crew, in a Berkeley Lab press release. “Considering we just turned it on a few months ago and during COVID restrictions, it is impressive we have such significant results already.”

Of the various detections the LZ experiment made in its 60-day run, 335 appeared promising, however none turned out to be WIMPs. That doesn’t imply WIMPs aren’t on the market, however it does remove a mass vary from rivalry. (This is the crux of what darkish matter detectors do: little by little, they rule out what plenty the particles can’t be.) Multiple physicists not too long ago informed Gizmodo that they assume the following large discovery in particle physics will come from a darkish matter detector like LZ.

This scientific run kicked off what’s expected to be a 1,000-day schedule. The latest spherical was additionally unblinded, so the LZ crew might monitor how the know-how behaved. Since it carried out as anticipated, the following scientific run may have its outcomes ‘salted,’ or peppered with phony indicators, to mitigate bias.

Twenty occasions extra knowledge shall be collected within the coming years, so maybe the wimpy WIMPs will lastly must face the music of their very own existence. Then once more, perhaps they don’t exist in any respect. We received’t know till we glance.

More: 10 Years After the Higgs Boson, What’s the Next Big Thing for Physics?