Dark matter has so far opposed every kind of detector created to find it. Due to its powerful gravitational mark in space, we know dark matter has to make up at least 85 percent of the complete mass of the Universe, but researchers cannot yet tell what it is made of.
Numerous extensive experiments that search for dark matter have hunted for signs of particles colliding into atomic nuclei via a process known as scattering, which can create small flashes of light and other signals in these engagements.
Hunting for Dark Matter
A new experiment, led by scientists from the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley, implies new ways for detecting the signals produced by dark matter particles that have their energy consumed by these nuclei.
The absorption process could give an impacted atom a kick that makes it to emit a lighter, energized particle such as an electron, and it might also create other kinds of signals, depending on the type of the dark matter particle.
The research focuses mostly on those cases where an electron or neutrino is discharged as the dark matter particle clashes with an atom’s nucleus. Published on May 4th in Physical Review Letters, the paper suggests that some existing research, including those that hunt for dark matter particles and processes associated with neutrinos, can be extended to also look for these absorption-concerning kinds of informer dark matter signals.
In addition, the study implies that new search in previously collected particle detector data could, most likely, identify these overlooked dark matter signals.
“In this field, we’ve had a certain idea in mind about well-motivated candidates for dark matter, such as the WIMP (weakly interacting massive particle),” said Jeff Dror, the lead author of the study who is a postdoctoral researcher in Berkeley Lab’s Theory Group and UC Berkeley’s Berkeley Center for Theoretical Physics.
Looking in Other Places For Dark Matter Particles
Dark matter sits right at the edges of the known fundamental laws of physics, covered by the Standard Model of particle physics. Although the WIMP program is rather easy to build into the Standard Model, scientists have not found it for a long time.
Therefore, physicists are now thinking of other places in which dark matter particles may be hiding, and other particle possibilities such as the hypothesized ‘sterile neutrinos’ that could also be included into the group of particles known as ‘fermions,’ which also comprise electrons, protons, and neutrinos.
“It’s easy, with small modifications to the WIMP paradigm, to accommodate a whole different type of signal,” Dror said. “You can make a huge amount of progress with very little cost if you step back a little bit in the way we’ve been thinking about dark matter.”
The team believes that dark matter could be hiding in existing data, as experiments that have massive volumes of detector material, with high sensitivity and incredibly low background ‘noise’ or unwanted interference from other kinds of particle signals, are especially perfect for this broad search for various types of dark matter signals. As a next step, the physicists in the team hope to work with experiment collaborations to examine existing data.