PNNL leads U.S. contribution to Belle II detector at Japan’s new SuperKEKB accelerator
⇐ cover image: Scientists and technicians insert one of the optical components of the iTOP detector into the Belle II detector in February 2016
This video from KEK discusses some of the science questions that Belle II and SuperKEKB seek to address
RICHLAND, Wash. – One of the world’s top particle accelerators has reached a milestone, achieving its «first turns» — circulating beams of particles for the first time — and opening a new window into the universe, a view that will give physicists access to a record rate of particle collisions in a tiny volume in space.
Japan’s SuperKEKB accelerator fills a unique role in the pantheon of atom smashers worldwide. It’s at the forefront of what physicists call the «intensity frontier,» designed to deliver more than 40 times the rate of collisions between particles than its predecessor.
Studying the particles produced in these collisions will give physicists a clearer view of the fundamental building blocks of the universe and provide new opportunities to explore physics that goes beyond today’s standard model of particle physics.
Last month, on Feb. 10, scientists at the accelerator circulated a beam of positrons moving close to the speed of light through a narrow tube around the 3-kilometer circumference of its main ring 10 meters underground. This past week, on Feb. 26, scientists there succeeded in circulating a beam of electrons moving near the speed of light in the opposite direction. The two events mark the device’s «first turns» — a milestone when beams of particles are circulated through many revolutions of an accelerator for the first time.
Next year, SuperKEKB will accelerate the two beams simultaneously, compress them into a smaller area than any other accelerator on Earth, then smash them together to produce copious quantities of B mesons and tau leptons — heavy particles whose decays can reveal new physics. Scientists who have spent years designing the collider and its detectors will then spend years sifting through the scientific fruits of their efforts.
The upgraded collider, located at the KEK laboratory in Tsukuba, Japan, was designed and created by a team of Japanese accelerator physicists. The Belle II detector that will observe the particles created in the collisions has been designed by a team of more than 600 scientists spanning 99 institutions in 23 countries across four continents.
Seventy-five U.S. scientists from 14 institutions have been involved in creating Belle II. The U.S. Department of Energy Office of Science has funded the nation’s contribution, and the department’s Pacific Northwest National Laboratory has led the effort. Jim Fast of PNNL is the project manager leading the U.S. contribution along with David Asner, the chief scientist for the project. Professor Tom Browder of the University of Hawaii is the spokesperson for the overall Belle II collaboration.
«Global cooperation is necessary to address the most compelling questions in particle physics,» said James Siegrist, associate director of science for high energy physics in the DOE Office of Science. «Now nations must specialize in the facilities that they build and provide access to those facilities to physicists from around the world. We appreciate that Japan is hosting this world-class facility where U.S. physicists will study rare particle interactions and look for new physics while in return contributing new state-of-the-art components to the international Belle II collaboration’s detector.»
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