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Nuclear and Particle Physics

Belle / Belle II

Installation at KEK

Very high precision quartz optics being installed at KEK will help measure the asymmetry between matter and antimatter in the universe.

Close up of iTOP

A close view of the imaging Time-Of-Propagation (iTOP) detector optics installed at Belle that contribute to our understanding of why the universe contains matter, but is nearly void of antimatter.

It's all about antimatter!

The Belle experiments involve an international cadre of more than 600 researchers who are working to understand why the universe contains matter, but is nearly void of antimatter. These studies are being conducted at the High Energy Accelerator Research Organization (known as KEK) in Tsukuba, Japan.

Belle is a specialized particle detector, three-stories tall, housing several million channels of precise radiation sensors that recorded the debris of electron-positron collisions from 1999 to 2010. The Belle II experiment at the SuperKEKB collider in Tsukuba, Japan, is being built with the help of PNNL staff. SuperKEKB will collide electrons and positrons in the center of Belle II. The collaboration looks forward to measuring, recording, and analyzing a few hundred billion of these collisions. PNNL staff members are contributing their expertise in physics, detectors, electronics, computing, data management and project management to this experiment.

PNNL leads the U.S. contribution to the Belle II experiment, providing high-performance computational capabilities to support researchers in data management and analysis. PNNL also works to deliver key elements of the particle identification system for Belle II, including the imaging Time-Of-Propagation (iTOP) detector optics and electronics and the Klong and Muon (KLM) detector upgrade that includes new scintillator detectors and new readout electronics.

Information on all aspects of the Belle and Belle II Collaborative is available at websites sponsored by KEK.

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