- Number 331 |
- February 21, 2011
Top quarks may provide clue to new asymmetry
The CDF detector at Fermilab.
The CDF collaboration at the Department of Energy’s Fermi National Accelerator Laboratory has found signs of a surprising asymmetry in the production of heavy, elementary particles known as top quarks.
Symmetry is a fundamental concept in the theories that describe the subatomic world. The observation of asymmetries can point to new types of particle interactions that go beyond the Standard Model of particle physics. In particular, physicists are looking for new types of asymmetric particle interactions that would explain why today’s matter-dominated universe is void of antimatter while the big bang must have produced equal amounts of matter and antimatter.In 2006, scientists working on the Collider Detector at Fermilab published their first analysis of how top quarks emerge from proton-antiproton collisions at Fermilab’s Tevatron. In 2008, both the CDF and DZero collaborations at Fermilab published frequently cited results that seemed to indicate an anomaly in the forward-backward symmetry of these collisions. This latest result adds more data, investigates the mass dependence of the collision patterns and raises the statistical significance of the asymmetry to the 3-sigma level. It increases the likelihood that the result is a clue to new physics beyond the Standard Model.
[Kurt Riesselmann, 630.840.3351,