Featured Research

from universities, journals, and other organizations

Physicists make atoms and dark matter add up

Date:
December 13, 2010
Source:
University of British Columbia
Summary:
Physicists have proposed a unified explanation for dark matter and the so-called baryon asymmetry -- the apparent imbalance of matter with positive baryon charge and antimatter with negative baryon charge in the universe.

UBC and TRIUMF physicists have proposed a unified explanation for dark matter and the so-called baryon asymmetry--the apparent imbalance of matter with positive baryon charge and antimatter with negative baryon charge in the Universe.

The visible Universe appears to be made of atoms, and each of these atoms carries a positive baryon charge equal to total number of protons and neutrons in its nucleus.

However, since the discovery of antimatter in 1932, researchers have wondered why the Universe doesn't hold a neutral baryon charge--requiring as much negatively charged antimatter as positively charged matter.

This net asymmetry of particles over antiparticles remains one of the biggest unsolved mysteries in physics.

"We've proposed a matter formation scenario where the positive baryon number of visible atoms is in balance with the equal and opposite negative baryon number of dark matter," says Kris Sigurdson, an assistant professor of Physics and Astronomy at UBC, who worked with colleagues at TRIUMF, Canada's National Laboratory for Particle Physics, and researchers at Brookhaven National Laboratory in the US, on the theory.

"This links the formation of atoms and dark matter and helps resolve the baryon asymmetry mystery, as the total dark plus visible baryon balance of the Universe is restored."

The proposal was published November 19 in the journal Physical Review Letters.

Observations of the the big bang's afterglow, the cosmic microwave background, by the WMAP satellite now show about 4.6 per cent of the Universe (by density) is comprised of atoms, with about five times more dark matter (23 per cent).

The cosmic balancing act proposed by the researchers may explain why the measured densities of dark matter and atoms differ only by a factor of five.

The researchers also predict an entirely new method to detect dark matter.

"Occasionally a dark-matter antiparticle may collide with and annihilate an ordinary atomic particle, releasing a burst of energy," says Sigurdson. "While extremely rare, this means dark matter might be observed in nucleon decay experiments on Earth that look for the spontaneous decay of protons."

Dark matter -- first hinted at nearly 80 years ago -- is an elusive material inferred to exist from measurements of its gravitational effects on visible matter in galaxies, background radiation, and the Universe as a whole. It interacts very weakly with ordinary matter and, while playing a key role in our Universe, is almost undetectable.

Hooman Davoudiasl, Brookhaven National Laboratory, New York and David Morrissey and Sean Tulin of TRIUMF's Theory Group, co-authored the letter.


Story Source:

The above story is based on materials provided by University of British Columbia. Note: Materials may be edited for content and length.


Journal Reference:

  1. Hooman Davoudiasl, David Morrissey, Kris Sigurdson, Sean Tulin. Unified Origin for Baryonic Visible Matter and Antibaryonic Dark Matter. Physical Review Letters, 2010; 105 (21): 211304 DOI: 10.1103/PhysRevLett.105.211304

Cite This Page:

University of British Columbia. "Physicists make atoms and dark matter add up." ScienceDaily. ScienceDaily, 13 December 2010. <www.sciencedaily.com/releases/2010/11/101129102456.htm>.
University of British Columbia. (2010, December 13). Physicists make atoms and dark matter add up. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2010/11/101129102456.htm
University of British Columbia. "Physicists make atoms and dark matter add up." ScienceDaily. www.sciencedaily.com/releases/2010/11/101129102456.htm (accessed July 31, 2014).

Share This




More Space & Time News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Supply Ship Takes Off for International Space Station

Supply Ship Takes Off for International Space Station

AFP (July 30, 2014) The European Space Agency's fifth Automated Transfer Vehicle (ATV-5) is takes off to the International Space Station on an Ariane 5 rocket from French Guiana. Duration: 00:34 Video provided by AFP
Powered by NewsLook.com
Raw: Rocket Launches Into Space With Cargo Ship

Raw: Rocket Launches Into Space With Cargo Ship

AP (July 30, 2014) Arianespace launched a rocket Tuesday from French Guiana carrying a robotic cargo ship to deliver provisions to the International Space Station. (July 30) Video provided by AP
Powered by NewsLook.com
In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) Video provided by AP
Powered by NewsLook.com
Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Newsy (July 27, 2014) The satellite is back under ground control after a tense few days, but with a gecko sex experiment on board, the media just couldn't help themselves. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins