Aug 10 2007
Werner Vogelsang, a physicist at the U.S. Department of Energy's Brookhaven National Laboratory, has received a 2007 Friedrich Wilhelm Bessel Research Award from the Humboldt Foundation for his outstanding research in theoretical physics. The award is given annually to approximately 20 internationally renowned scientists and scholars who have received their doctoral degree within the past 12 years and who perform their research outside of Germany. The award allows recipients to work on research projects of their own choice in cooperation with colleagues in Germany for periods of six months to a year.
"I am delighted to receive this award," Vogelsang said. "It gives me the opportunity to start new collaborations, which will benefit both my own theoretical research as well as Brookhaven's Relativistic Heavy Ion Collider [RHIC] program."
Vogelsang makes calculations based on a physics theory called quantum chromodynamics, which describes the interactions of subatomic particles, and compares his results to data obtained by scientists who perform experiments at RHIC to understand how protons get their spin - a fundamental question about elementary particles that has not been adequately answered, despite decades of study.
Protons are made of smaller particles called quarks, which are held together by particles called gluons. Protons, quarks and gluons have an intrinsic property known as spin, similar to Earth spinning on its axis. Scientists collide polarized protons - protons that mostly spin in the same direction - at RHIC, and by "seeing" the products of these collisions via huge detectors, scientists hope to learn more about the proton's spin.
In earlier work at accelerators in which photons are used to probe protons, Vogelsang, like other researchers, has found that the spin of quarks accounts for only about 20 percent of proton spin - a surprise, since scientists had thought that quarks would account for a major part of it. In more recent work at RHIC, data combined with Vogelsang's calculations indicate that gluon spin also accounts for a very small portion of proton spin - another surprise, since gluons were the next most likely component to provide the spin. More research is needed to solve the proton-spin mystery.
In addition to ongoing research at RHIC, Vogelsang is planning to work with collaborators at the University of Regensburg in Germany to extend his theoretical calculations to polarized proton-antiproton scattering experiments, expected to be performed at an accelerator in Darmstadt, Germany. These studies are expected to provide new insights into the structure of matter.