Results from two leading dark matter experiments—XENONnT and PandaX-4T—rule out an enigmatic signal detected in 2020 and set new constraints on dark matter particle candidates consisting of light fermions, respectively.
Over the past decade, physicists have repeatedly scrutinized tanks containing tons of liquid xenon, hoping to spot the flashes of light that might indicate a collision between a dark matter particle and a xenon atom (see Viewpoint: Dark Matter Still at Large). Most of these studies were dedicated to detecting so-called weakly interacting massive particles (WIMPs), a leading dark matter candidate with a mass greater than 10 GeV. Now researchers have sifted through a new set of data for a much lighter prize: fermionic dark matter with a mass of a few tens of MeV [1]. Although the team found no signal beyond the expected background level, they have set the strongest constraints yet on models of sub-GeV fermionic dark matter.
The dataset is the first obtained by the PandaX-4T experiment at the China Jinping Underground Laboratory. The PandaX team searched this data for evidence of a beyond-the-standard-model interaction in which a fermionic dark matter particle is absorbed by the nucleus of a xenon atom. After the absorption, the xenon nucleus should recoil while emitting either a neutrino or an antineutrino. The interaction should also cause an energy deposition in the form of photons and electrons, which would register on photodetectors at the ends of the tank. Unlike the scattering of WIMPs, which is predicted to produce a broad-spectrum energy deposition, the absorption by nuclei of fermionic dark matter particles should deposit energy only in a narrow range.
The data collected so far represent the equivalent of exposing 0.6 tons of liquid xenon to hypothetical fermionic dark matter for one year. When PandaX-4T concludes in 2025, it will have achieved a cumulative exposure 10 times greater, generating even stronger constraints on theory.
Circa 2008 0.0!
A normal digital camera can take snaps of objects not directly visible to its lens, US researchers have shown. The “ghost imaging” technique could help satellites take snapshots through clouds or smoke.
Physicists have known for more than a decade that ghost imaging is possible. But, until now, experiments had only imaged the holes in stencil-like masks, which limited its potential applications.
Continue reading “Quantum camera snaps objects it cannot ‘see’” »
😗 Our universe is wild o.o!
Quantum nonlocality is known to be reducible to quantum uncertainty and steering, but it is unclear whether steering is actually as essential as uncertainty. Here, the authors show that both steering and uncertainty play a role in determining optimal strategies in nonlocal games.
With a soaring public garden and rooftop farm, the 919-foot CapitaSpring skyscraper is the tropical city-state’s latest nature-inspired building.
See how NASA’s DART mission may help us save life on Earth by showing us how to avert a future doomsday from an asteroid striking Earth.
Worm-hole generators by the pound mass: https://greengregs.com/
Inspired by living things from trees to shellfish, researchers at The University of Texas at Austin set out to create a plastic much like many life forms that are hard and rigid in some places and soft and stretchy in others. Their success—a first, using only light and a catalyst to change properties such as hardness and elasticity in molecules of the same type—has brought about a new material that is 10 times as tough as natural rubber and could lead to more flexible electronics and robotics.
The findings are published today in the journal Science.
Last year, the pharmaceutical company Biogen released a drug called Aduhelm. It was the first new Alzheimer’s drug approved by the FDA in almost 20 years, but its rollout was mired in controversy — vast swaths of experts decried its approval, claiming there simply wasn’t enough evidence to support its efficacy, while the Journal of American Medicine (JAMA) rejected Biogen’s key Aduhelm paper. Shortly thereafter, Medicare chose to limit coverage of the drug.
All that is to say that given last year’s Aduhelm spectacle, you’d be forgiven for doubting what appears to be a promising development in Biogen’s continued Alzheimer’s drug development. And that’s just what it announced with a collaborator, fellow pharmaceutical maker Eisai, on Tuesday. But that being said, initial data suggests that the new drug is actually proving quite successful in late-stage clinical trials — enough so that Biogen might have a redemption arc, after all.
That new drug, lecanemab, is an anti-amyloid medication. An amyloid is a type of protein, and a normal one for brains to produce. An overabundance of amyloids, however, is believed to be caused by a disruption in a healthy brain’s built-in protein disposal system, resulting in a plaque; although our understanding is still fuzzy, brains with Alzheimer’s are shown to have abnormal plaque levels, so the idea is that anti-amyloid lecenameb, administered intravenously, could scrub that plaque away.
