Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


UCI study finds dark matter is for superWIMPs


New class of superweak particles may reveal secrets of hidden mass in universe

A UC Irvine study has revealed a new class of cosmic particles that may shed light on the composition of dark matter in the universe.

These particles, called superweakly interacting massive particles, or superWIMPs, may constitute the invisible matter that makes up as much as one-quarter of the universe’s mass.

UCI physicists Jonathan Feng, Arvind Rajaraman and Fumihiro Takayama report that these new superWIMPs have radically different properties from weakly interacting massive particles (WIMPs), which many researchers have long looked to as the leading dark matter candidate. The study was posted July 3 on the online version of Physical Review Letters (

The identity of dark matter is one of the most puzzling problems for those who study the nature of our cosmos. While as much as a quarter of the universe is made of this invisible mass, which plays a vital role in the structure of the universe, almost nothing is known about its composition. It is believed to be the celestial glue that holds galaxies together in their distinctive spiral shapes.

To identify this elusive dark matter, many astrophysical researchers have turned to WIMPs. These particles emit no light and are very difficult to detect. However, as their name suggests, they do have weak-force interactions with other particles, and they are expected to leave visible traces in experiments. Currently, research groups throughout the world are searching for WIMPs, so far without success.

But in studying theories that predict WIMP dark matter, Feng and his colleagues found that in many of these theories WIMPs do not live forever. According to Feng, many theorists have assumed WIMPs to be the lightest particles and thus the most stable. “But we’ve found that WIMPs are often not stable at all, because they can decay into lighter particles,” Feng said, “and, all of a sudden, the WIMPs disappear.”

These new, lighter particles are superWIMPs. Like their progenitors, they emit no light and have both mass and gravitational force. But they are incapable of the type of weak-force interactions that WIMPs have; they can only interact gravitationally. Since the gravitational force is not as strong as the weak force, these interactions are, as Feng calls them, “superweak.” In turn, these particles will rarely, if ever, collide with other particles.

And, unlike WIMPs, superWIMPs are incapable of decaying into other particles. “They are absolutely stable,” Feng said. “And because of this, they are a completely different, but perfectly viable, alternative for dark matter.”

Like WIMPs, superWIMPs only exist theoretically. In fact, because superWIMPs do not have weak-force interactions, they are predicted to be impossible to detect by conventional experimental methods. But Feng and his colleagues point to some alternative tests to prove their existence. They found that observations of old stars and the cosmic microwave background of the universe can reveal clues for superWIMPs.

“One place to look for evidence is in the cosmic microwave background, which in essence is the afterglow of the Big Bang,” Feng said. “This background is very uniform. But according to our theory, WIMP decay would set loose a zoo of particles that would create deviations in this background. If such deviations are found, they would provide a particle fingerprint for the existence of superWIMP dark matter.”

Feng and his collaborators are currently investigating hints for superWIMPs in present data and are considering further studies that might provide evidence for the existence of superWIMP dark matter.

The research was funded by UC Irvine and a CAREER Award from the National Science Foundation.

Tom Vasich | UC Irvine
Further information:

More articles from Physics and Astronomy:

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>