Japan’s High Energy Accelerator Research Organization (KEK) has been steadily improving the performance of its flagship electron-positron collider, SuperKEKB, since it produced its first electron-positron collisions in April 2018.  At 20:34 on 15th June 2020, SuperKEKB achieved the world’s highest instantaneous luminosity for a colliding-beam accelerator, setting a record of 2.22×10³⁴ cm^-2 s^-1. Previously, the KEKB collider, which was SuperKEKB’s predecessor and was operated by KEK from 1999 to 2010, had achieved the world’s highest luminosity, reaching 2.11×10³⁴ cm^-2 s^-1. KEKB’s record was surpassed in 2018, when the LHC proton-proton collider at the European Organization for Nuclear Research (CERN) overtook the KEKB luminosity at 2.14×10³⁴ cm^-2 s^-1. SuperKEKB’s recent achievement returns the title of world’s highest luminosity colliding-beam accelerator to KEK. (The current record is 2.40×10³⁴ cm^-2 s^-1, obtained at 00:53 JST on June 21st.)

For more details, please see Press release (KEK).

KMI members play leading roles in various aspects of the Belle II Experiment. Prof. Iijima as the spokesperson of Belle II Collaboration, Associate prof. Alessandro Gaz as the Physics Coordinator, Associate prof. Kodai Matsuoka, Assistant prof. Yuji Kato, and Assistant prof. Qidong Zhou are actively involved in the project. 

This record is only a small step toward the design luminosity but not an easy step. It is a big achievement after overcoming many difficulties. Many small steps like this will lead us to accumulate more data and to approach the mysteries of the universe. (Associate prof. Kodai Matsuoka)

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Press release (KEK)

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