Just as astounding was the ability of the STAR detector to capture and identify these heavy antimatter particles among the trillions of particles created in collisions at Brookhaven each year. It would be far easier, Geurts said, to find the proverbial needle in a haystack, but the new time-of-flight detector, which Rice scientists designed and built over the course of a decade, was up to the task. Jabus Roberts, a Rice professor of physics and astronomy, and research scientist Geary Eppley, both co-authors on the new paper, started the research that led to the detector more than 10 years ago. Eppley and William Llope, senior faculty fellow in physics and astronomy and also a co-author, managed the construction and installation of the apparatus.
The detector is a set of 23,000 sensors that surround STAR, short for Solenoidal Tracker at RHIC. These sensors identify the types of subatomic particles released when heavy nuclei collide. The detector tells researchers how long it takes a particle to travel from its creation to the point it passes through one of the sensors and is accurate to a 10th of a billionth of a second.
Rice played a role in the discovery even beyond its creation of the critical detector. A Rice graduate student found the first evidence that antihelium-4 was being created in collisions at RHIC. Jianhang Zhou, now working in private industry in Houston, "dedicated a chapter in his thesis to the fact that he had found two candidates (for antihelium-4)," Geurts said. "At that time, we needed more statistics and a time-of-flight detector to confirm his findings." I
|Contact: David Ruth|