Rapid 3D track reconstruction with the BaBar trigger upgrade

Abstract As the PEP-II luminosity increases the B a B ar trigger and dataflow systems must accomodate the increasing data rate. A significant source of background events at the first trigger level comes from the beam particle interactions with the beampipe and synchrotron masks, which are separated from the interaction region by more than 20 cm . The B a B ar trigger upgrade will provide 3D tracking capabilities at the first trigger level in order to remove background events by distinguishing the origin of particle tracks. Each new z 0 p T Discriminator board processes over 1 Gbyte of data per second in order to reconstruct the tracks and make trigger decisions based upon the 3D track parameters.