K. Byrum et al., SHOWER MAXIMUM TRIGGER FOR ELECTRONS AND PHOTONS AT CDF, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 364(1), 1995, pp. 144-149
For the 1994 Tevatron collider run, CDF has upgraded the electron and
photon trigger hardware to make use of shower maximum information from
the central shower maximum detector. For electrons, the upgrade has r
esulted in a 50% reduction in backgrounds while retaining approximatel
y 90% of the signal. The new trigger also eliminates the background to
photon triggers from single-phototube discharge.