Electrons and Positrons Collide for the first time in the SuperKEKB Accelerator

Electrons and positrons accelerated and stored by the SuperKEKB particle accelerator collided for the first time on 26 April 2018 0:38, GMT+09:00 at KEK in Tsukuba, Japan. The Belle II detector, installed at the collision point, recorded events from electron-positron annihilation (matter-antimatter annihilation) of the beam particles, which produced other particles likely including beauty quark and anti-beauty quark pairs as well as other hadronic and Bhabha scattering events (1). These are the first electron-positron collisions at the KEK particle physics laboratory in 8 years; the previous KEKB particle collider ceased its operations in 2010.