SuperKEKB Achieved the New Luminosity Record

Abstract

SuperKEKB achieved the world’s highest luminosity record of 2.40×10³⁴ cm⁻² s⁻¹. SuperKEKB adopts a novel collision method named nano-beam scheme in which the colliding beams are squeezed to extremely small sizes at the interaction point. The crab waist (CW) collision scheme was also applied in April 2020 to suppress beam–beam blowup. Following a brief introduction of the nano-beam and CW collision schemes, the overview of collision operation and beam tuning, and the issues which should be solved for further luminosity performance are reported.