Tracking particles containing charm quarks offers insight into how quarks combine
Nuclear physicists are trying to understand how particles called quarks and gluons combine to form hadrons, composite particles made of two or three quarks. To study this process, called hadronization, a team of nuclear physicists used the STAR detector at the Relativistic Heavy Ion Collider—a U.S. Department of Energy Office of Science user facility for nuclear physics research at DOE's Brookhaven National Laboratory—to measure the relative abundance of certain two- and three-quark hadrons created in energetic collisions of gold nuclei. The collisions momentarily "melt" the boundaries between the individual protons and neutrons that make up the gold nuclei so scientists can study how their inner building blocks, the quarks and gluons, recombine.