Apex A Experiment PDF Download

APEX is an experiment at Thomas Jefferson National Accelerator Facility (JLab) in Virginia, USA, that searches for a new gauge boson (A') with sub-GeV mass and coupling to ordinary matter of g' ~ (10-6 - 10−2)e. Electrons impinge upon a fixed target of high-Z material. An A' is produced via a process analogous to photon bremsstrahlung, decaying to an e+e− pair. A test run was held in July of 2010, covering mA' = 175 to 250 MeV and couplings g'/e> 10−3. A full run is approved and will cover mA' ~ 65 to 525 MeV and g'/e> 2.3 x 10−4, and is expected to occur sometime in 2016 or 2017.