(E) NEW FLAVOR PRODUCTION IN y, u, v, AND HADRON BEAMS*

During the last few years, the main emphasis in the study of heavy particle production (i.e. e+emainly charm) by other means than annihilation has been on the production mechanisms. Because of the relative cleanliness of the charm signal in the e+eprocess, most of the data on the properties of the charm particles has originated from that source. There are already indications, however, that this situation is changing. Improved detection techniques coupled with much higher intrinsic production rates suggest that in the future the study of the properties of charm particles will cease to be an exclusive domain of e+emachines. This review, however, will concentrate mainly on the production data in the y, u, v and hadron beams. This is partly because the decay properties have been covered in the review talk of George Trilling and partly because up to now most experiments did emphasize mainly the production aspects. In addition there has been recently a considerable interest in trying to explain most of these data phenomenologically by use of first order QCD diagrams, i.e. photon gluon fusion diagram (Fig. la) in the case of photo and muonproduction of charmed hadrons and gluon-gluon or quark-quark fusion (Fig. lb,c) and charmed sea excitation (Fig. ld,e) for hadronic production of charmed particles. These mechanisms relate the quark structure functions as measured in the massive di-lepton pair production experiments and the deep inelastic scattering experiments (p, e, and v) to the production distribution of the charmed hadrons. In addition the gluon diagrams, if dominant, allow one to measure the gluon distributions of the IT, K, and the nucleon. One can contrast this situation with the production of 9 fJ 9 F (a) (b) (cl