出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：In this talk, we have taken into account the main decay channel of J=y when travelling inside a nucleus. In analogy to all vector mesons in SU(3), where the main decay channel is to two pseudoscalars, in the case of the J=y the meson meson channel to which it couples strongly is D¯D. Taking this into account we study the J=yN ! ¯DLc and J=yN ! ¯DSc mediated by D-exchange. To obtain the couplings we use an extension to SU(4) of the local hidden gauge Lagrangians as done in [1]. Analogously, we consider the mechanisms where the exchanged D collides with a nucleon and gives pLc or pSc. The sum of these channels produces a J=yN inelastic cross section which is larger than the elastic one and is responsible for the depletion of J=yN when propagating through nuclear matter. The cross section has its peak around p s=4415 MeV, where the virtual D and one N give rise to the Lc(2595) resonance. We have studied the transparency ratio for photon induced J=y production in nuclei at 10 GeV and find that about 30 - 35 % of the J=y produced in heavy nuclei are absorbed inside the nucleus. This ratio is in line with depletions of J=y through matter observed in other reactions.
