Featured Research

from universities, journals, and other organizations

Surprising new evidence for asymmetry between matter and antimatter

Date:
May 24, 2010
Source:
University of California - Riverside
Summary:
Why is there matter in the universe and not antimatter, its opposite? Physicists at Fermi National Accelerator Laboratory have announced that they may have an answer.

Why is there matter in the universe and not antimatter, its opposite?

Physicists at Fermi National Accelerator Laboratory, including John Ellison, a professor of physics at UC Riverside, have announced that they have found evidence for a significant violation of matter-antimatter symmetry in decays of B-mesons, which are exotic particles produced in high energy particle collisions.

To arrive at their result, the research team, known as the DZero collaboration, analyzed billions of proton-antiproton collisions at Fermilab's Tevatron particle collider, and found a 1 percent excess of pairs of muons over pairs of antimuons produced in the decays of B-mesons. Muons, which occur naturally in cosmic rays, are fundamental particles similar to electrons but 200 times heavier.

Ellison said this result is exciting and surprising since it is not predicted in the Standard Model, the comprehensive theory that explains the interactions between all fundamental elementary particles.

He explained that the dominance of matter we observe in the universe is possible only if there are differences, called "CP violation," in the behavior of particles and antiparticles.

"The reason this is important is that CP violation -- the fact that physics does not look the same when particles and antiparticles are interchanged and all processes are mirror-reflected -- is one of the three ingredients identified by Andrei Sakharov, the famous Soviet physicist and dissident, needed to explain the matter-antimatter asymmetry observed in our universe," Ellison said. "That the universe is completely dominated by matter is a mystery because the Big Bang theory predicts that there should have been equal amounts of matter and antimatter."

According to Ellison and his DZero peers, the explanation for the dominance of matter in the present day universe is that the CP violation treated matter and antimatter differently and allowed the early universe to evolve into a situation with matter dominating completely over antimatter.

"CP violation as predicted in the Standard Model has been observed before but at a level many orders of magnitude too small to explain the asymmetry," Ellison said. "This is the first evidence for anomalous CP violation. If confirmed by further measurements, this points to new physics phenomena in particle interactions that give rise to the matter-antimatter asymmetry, and may be another step forward in our understanding of why matter dominates over antimatter in the universe."

The DZero result is based on data collected over the last eight years by the DZero experiment at Fermilab. Besides Ellison, the UC Riverside co-authors of the paper, submitted for publication in Physical Review D, are Ann Heinson, Liang Li, Mark Padilla, and Stephen Wimpenny.

DZero is an international experiment of about 500 physicists from 86 institutions in 19 countries. It is supported by the U.S. Department of Energy, the National Science Foundation and a number of international funding agencies.

Fermilab is a national laboratory funded by the Office of Science of the U.S. Department of Energy.


Story Source:

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


Cite This Page:

University of California - Riverside. "Surprising new evidence for asymmetry between matter and antimatter." ScienceDaily. ScienceDaily, 24 May 2010. <www.sciencedaily.com/releases/2010/05/100524161338.htm>.
University of California - Riverside. (2010, May 24). Surprising new evidence for asymmetry between matter and antimatter. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2010/05/100524161338.htm
University of California - Riverside. "Surprising new evidence for asymmetry between matter and antimatter." ScienceDaily. www.sciencedaily.com/releases/2010/05/100524161338.htm (accessed July 25, 2014).

Share This




More Matter & Energy News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com
Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
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