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Hadronic Production of Charmed Particles

Properties of charmed particles produced in hadronic interactions have been studied since 1984 in the NA32 experiment at the CERN SPS. A cross section for charm production of the order of 10 pb is expected at fi = 20 GeV/2. Therefore, hadronic reactions are potentially a good source of charmed particles. However, the extraction of a clean signal is difficult because the total inelastic cross section is a factor of 1000 larger and it is the source of a huge combinatorial background. The relatively long lifetimes of the charmed particles (lO-’’-IO-’* s) will provide the necessary signature. A high resolution vertex detector made of silicon microstrip detectors (MSDs) allows the reconstruction of secondary decay vertices. The good particle identification capability of the spectrometer will further reduce the background and resolve ambiguities between different charmed particles. There are two domains where the NA32 experiment contributes: the understanding of the production mechanisms of the charmed particles in hadronic reactions and the study of decay properties of the charmed particles (lifetimes, branching ratios).