Prompt photon production in π-p-, π+p- and pp- collisions at 300 GeV/c

The NA24 experiment measures the yield of prompt photons and π0's originating from interactions of π-, π+ and protons on hydrogen at 300 GeV/c for transverse momenta up to 7.0 GeV/c. The separation of prompt photons from decay photons of π0's and eta's is achieved by a photon position detector of high granularity followed by a calorimeter for electromagnetic and hadronic showers. Inclusive cross sections for prompt photons are presented along with the ratio of cross sections sigma(π-p →γx)/sigma(π+p →γx). The latter quantity compares favorably with QCD-calculations. Only preliminary results are presented in this paper. 7 refs