The E705 scintillation glass/lead glass electromagnetic calorimeter is described. The trigger used for recording high transverse momentum direct photon signals from 300 GeV/c .pi./sup /minus//, .pi., /bar p/, p interactions in a Li7 target is explained. Preliminary results on the response of this direct photon trigger and electromagnetic calorimeter and expected event sensitivities are presented. 14 refs., 9 figs., 2 tabs.
The Advanced Research Workshop on QeD Hard Hadronic Processes was held on 8-13 October 1987 at Hotel on the Cay, St. Croix, U. S. Virgin Islands. The underlying theme of the workshop, the first in a series, was an examination, both theoretical and experimental, of the state of understanding of Quantum Chromodynamics. Because of the pervasiveness of the strong interactions in all aspects of high energy physics, QCD is central to many problems in elementary particle physics. Therefore, this workshop was organized to provide a forum in which the theory Quantum Chromodynamics cou 1 d be confronted with experi ment. The workshop was organ i zed in four sessions, each of which concentrated on a major experimental arena in which a hard QCD process can be measured experimentally. A fifth session was rlevoted to global issues which effect all QCD processes. Each session began with a survey of the theoretical developments in the particular area and concluded with a round table which discussed the various information presented in the course of the discussions. A session of the workshop was devoted to the direct production of high transverse momentum photons in hadronic interactions. Data from several experiments, either completed or in progress at CERN (NA3, NA24, WA70, UA6, CCOR, R806, AFS, RllO, UA1 and UA2), were di scussed and the prospects for two new upcomi ng experi ments from Fermil ab (E-705, E-706) were presented.
A search for direct photon production has been performed at Fermilab in 200 and 300 GeV/c proton-Be interactions over a wide range of X/sub F/ and P/sub perpendicular to/. An excess of photons has been detected which when interpreted as single photon production yields a .gamma./.pi.° ratio which averages .070 +- 025 in the region 1.5
