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تسجيل مستخدم جديدpi N and eta p deexcitation channels of the N^* and Delta baryonic resonances between 1470 and 1680 MeV
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Two reactions, pp->ppX and pp->ppi^+X, are used to study the 1.47<M<1.68 GeV baryonic mass range. Three different final states are considered in the invariant masses: N^* or Delta^+, ppi^0, and peta. The last two channels are defined by software cuts applied to the missing mass of the first reaction. Several narrow structures are extracted with widths sigma(Gamma) varying between 3 and 9 MeV. Some structures are observed in one channel but not in others. Such nonobservation may be due either to the spectrometer momenta limits or to the physics (e.g. no such disintegration channel is allowed from the narrow state considered). We tentatively conclude that the broad Particle Data Group (PDG) baryonic resonances N(1520)D13, N(1535)S11, Delta(1600)P33, and N(1675)D15 are collective states built from several narrow and weakly excited resonances, each having a (much) smaller width than the one reported by PDG.
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