University of Mississippi. Department of Physics and Astronomy.
Abstract
Experiment 791 at Fermilab`s Tagged Photon Laboratory has just accumulated a high statistics charm sample by recording 20 billion events on 24000 8mm tapes. A 500 GeV/c {pi}{sup {minus}} beam was used with a fixed target and a magnetic spectrometer which now includes 23 silicon microstrip planes for vertex reconstruction. A new data acquisition system read out 9000 events/sec during the part of the Tevatron cycle that delivered beam. Digitization and readout took 50 {mu}S per event. Data was buffered in eight large FIFO memories to allow continuous event building and continuous tape writing to a wall of 42 Exabytes at 9.6 MB/sec. The 50 terabytes of data buffered to tape is now being filtered on RISC CPUs. Preliminary results show D{sup 0} {yields} K{sup {minus}}{pi}{sup +} and D{sup +} {yields} K{sup {minus}}{pi}{pi}{sup +} decays. Rarer decays will be pursued
