Bottom quarks reveal something of their identity

July 7, 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: With collider set to reboot, physicists look beyond the Higgs

Related Stories

With collider set to reboot, physicists look beyond the Higgs

December 17, 2014

So much for the warmup laps. Harvard physicists are looking with anticipation to the spring, when the Large Hadron Collider (LHC) at CERN, Switzerland, fires up after a two-year hiatus for repairs and upgrades. The last time ...

New Results Change Estimate of Higgs Boson Mass

June 9, 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

Power grid forecasting tool reduces costly errors

July 30, 2015

Accurately forecasting future electricity needs is tricky, with sudden weather changes and other variables impacting projections minute by minute. Errors can have grave repercussions, from blackouts to high market costs. ...

New Horizons data hint at underground ocean

July 30, 2015

Pluto wears its heart on its sleeve, and that has scientists gleaning intriguing new facts about its geology and climate. Recent data from NASA's New Horizons probe—which passed within 7,800 miles of the surface on July ...

The sound of music, according to physicists

July 30, 2015

Joshua Bodon is sick of hearing "Somewhere Over the Rainbow." More specifically, he's sick of hearing one 25-second clip of the song repeated more than 550 times.

Unusual red arcs spotted on icy Saturn moon Tethys

July 30, 2015

Like graffiti sprayed by an unknown artist, unexplained arc-shaped, reddish streaks are visible on the surface of Saturn's icy moon Tethys in new, enhanced-color images from NASA's Cassini spacecraft.

0 comments

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.