Bottom quarks reveal something of their identity

Jul 07, 2005

Dutch researcher Bram Wijngaarden investigated how bottom quarks are created during collisions between protons and antiprotons. Wijngaarden's measurements have contributed to a better understanding of the theory, and can be used to explain why the production of these quarks during such collisions is higher than had originally been expected.

Bram Wijngaarden investigated the creation of bottom quarks using the D zero experiment of the particle accelerator at the Fermi lab in Chicago, United States. In this Tevatron particle accelerator, protons and antiprotons collide with each other. Bottom quarks are created as a result of the strong nuclear force that arises during these collisions.

In the 1990s measurements with the Tevatron particle accelerator and with the Hera particle accelerator in Hamburg revealed that the production of bottom quarks was higher than had been theoretically predicted. Since then theoretical physicists have done a lot of work to explain the difference. Wijngaarden's measurements must reveal whether the theory provides a good description of the reality.

Bottom quarks

Bottom quarks are created during high-energy collisions between particles. The bottom quark is one of six quarks. Together with the top quark it is one of the heaviest quarks. These quarks are only found under extreme circumstances, such as during collisions between particles. After the collision the bottom quarks decay into other particles. Measuring devices detect the electrical signals left behind by the particles. Signals from the decay products of the bottom quarks can be distinguished from the other particles released because bottom quarks are heavier and on average breakdown slightly less quickly.

By measuring the angle between two bottom quarks from the same collision, Wijngaarden could study the strong nuclear force directly. This angle was measured as the angle between the avalanches from the decay products of the bottom quarks. In the first-order approach, the theory predicts that the two bottom quarks always move apart from each other at an angle of 180 degrees. Wijngaarden showed that in a number of cases the angle is much smaller. The second-order approach predicts that the angle is much smaller in a number of cases but the average size of the angle measured by the researcher differed from the result obtained using this approach. The strong nuclear force can be tested more accurately with new measurements made with the help of methods developed by Wijngaarden.

Bram Wijngaarden's research was funded by NWO.

Source: Netherlands Organization for Scientific Research

Explore further: Two new baryon particles discovered in agreement with York U prediction

add to favorites email to friend print save as pdf

Related Stories

New Results Change Estimate of Higgs Boson Mass

Jun 09, 2004

In a case of the plot thickening as the mystery unfolds, the Higgs boson has just gotten heavier, even though the subatomic particle has yet to be found. In a letter to the scientific journal Nature, published in the June ...

Recommended for you

New technique allows ultrasound to penetrate bone, metal

5 hours ago

Researchers from North Carolina State University have developed a technique that allows ultrasound to penetrate bone or metal, using customized structures that offset the distortion usually caused by these ...

Taming the Boltzmann equation

9 hours ago

Physicists at Ludwig Maximilian University of Munich, Germany, have developed a new algorithm that is capable of solving the Boltzmann equation for systems of self-propelled particles. The new method also ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.