Key Takeaways
With 280 days of knowledge, the LUX-ZEPLIN (LZ) collaboration has made a world-leading seek for weakly interacting huge debris (WIMPs) in spaces no experiment has probed prior to.
The brand new result’s just about 5 occasions higher than the former international’s best possible printed outcome and unearths no proof of WIMPs above a mass of 9 GeV/c2.
Researchers have best scratched the outside of what LZ can do. With the detector’s remarkable sensitivity and their complex research ways, the collaboration is primed to find darkish topic if it exists throughout the experiment’s achieve and to discover different uncommon physics phenomena.
Understanding the character of darkish topic, the invisible substance that makes up many of the mass in our universe, is likely one of the largest puzzles in physics. New effects from the sector’s maximum delicate darkish topic detector, LUX-ZEPLIN (LZ), have narrowed down probabilities for one of the crucial main darkish topic applicants: weakly interacting huge debris, or WIMPs.
LZ, led by way of the Division of Power’s Lawrence Berkeley Nationwide Laboratory (Berkeley Lab), hunts for darkish topic from a cavern just about one mile underground on the Sanford Underground Analysis Facility in South Dakota. The experiment’s new effects discover weaker darkish topic interactions than ever searched prior to and extra restrict what WIMPs might be.
“Those are new world-leading constraints by way of a large margin on darkish topic and WIMPs,” stated Chamkaur Ghag, spokesperson for LZ and a professor at College School London (UCL). He famous that the detector and research ways are acting even higher than the collaboration anticipated. “If WIMPs have been throughout the area we searched, we’d had been in a position to robustly say one thing about them. We all know we have now the sensitivity and gear to look whether or not they’re there as we seek decrease energies and accrue the majority of this experiment’s lifetime.”
The collaboration discovered no proof of WIMPs above a mass of 9 gigaelectronvolts/c2 (GeV/c2). (For comparability, the mass of a proton is relatively lower than 1 GeV/c2.) The experiment’s sensitivity to faint interactions is helping researchers reject doable WIMP darkish topic fashions that don’t are compatible the information, leaving considerably fewer puts for WIMPs to cover. The brand new effects had been offered at two physics meetings on August 26: TeV Particle Astrophysics 2024 in Chicago, Illinois, and LIDINE 2024 in São Paulo, Brazil. A systematic paper can be printed within the coming weeks.
The effects analyze 280 days’ price of knowledge: a brand new set of 220 days (amassed between March 2023 and April 2024) mixed with 60 previous days from LZ’s first run. The experiment plans to gather 1,000 days’ price of knowledge prior to it leads to 2028.
“Should you call to mind the seek for darkish topic like on the lookout for buried treasure, we’ve dug virtually 5 occasions deeper than any person else has prior to now,” stated Scott Kravitz, LZ’s deputy physics coordinator and a professor on the College of Texas at Austin. “That’s one thing you don’t do with 1,000,000 shovels – you do it by way of inventing a brand new device.”
An array of photomultiplier tubes which can be designed to stumble on indicators from particle interactions going on inside of LZ’s liquid xenon detector. (Credit score: Matthew Kapust/Sanford Underground Analysis Facility)
LZ’s sensitivity comes from the myriad techniques the detector can scale back backgrounds, the false indicators that may impersonate or cover a gloomy topic interplay. Deep underground, the detector is protected against cosmic rays coming from area. To scale back herbal radiation from on a regular basis gadgets, LZ was once constructed from hundreds of ultraclean, low-radiation portions. The detector is constructed like an onion, with every layer both blocking off out of doors radiation or monitoring particle interactions to rule out darkish topic mimics. And complicated new research ways lend a hand rule out background interactions, in particular the ones from the most typical wrongdoer: radon.
This outcome could also be the primary time that LZ has carried out “salting” – a method that provides pretend WIMP indicators all the way through information assortment. By means of camouflaging the actual information till “unsalting” on the very finish, researchers can steer clear of subconscious bias and stay from overly decoding or converting their research.
“We’re pushing the boundary right into a regime the place folks have now not seemed for darkish topic prior to,” stated Scott Haselschwardt, the LZ physics coordinator and a up to date Chamberlain Fellow at Berkeley Lab who’s now an assistant professor on the College of Michigan. “There’s a human tendency to wish to see patterns in information, so it’s in point of fact vital whilst you input this new regime that no bias wanders in. If you’re making a discovery, you wish to have to get it proper.”
