2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/114387The Beijing Electron Collider is being upgraded (BEPCII) to a two-ring collider with a design luminosity of $1 \times 10^{33}$cm$^{-2}$ s$^{-1}$ at a center-of-mass energy of 3.89 GeV. It will operate between 2 and 4.2 GeV in the center of mass. With this luminosity, the BESIII detector will be able to collect, for example, 10 billion $J/ψ$ events in one year of running. This will be a unique facility in the world opening many physics opportunities. BEPCII and BESIII are currently under construction, and commissioning of both is expected to begin in summer 2007.Talk presented at "e+e- collisions from phi to psi", Novosibirsk, Russia, February 27-March 2, 2006. Six pages with nine figuresInstrumentation and DetectorsHigh Energy Physics - Experimenttext