Ultra high energy photons and neutrinos with JEM-EUSO

Ultra high energy photonsand neutrinosare carriers of very important astrophysical information. They may be produced at the sites of cosmic rayacceleration or during the propagation of the cosmic raysin the intergalactic medium. In contrast to charged cosmic rays, photonand neutrinoarrival directions point to the production site because they are not deflected by the magnetic fields of the Galaxy or the intergalactic medium. In this work we study the characteristics of the longitudinal development of showersinitiated by photonsand neutrinosat the highest energies. These studies are relevant for development of techniques for neutrinoand photonidentification by the JEM-EUSO telescope. In particular, we study the possibility of observing the multi-peak structure of very deep horizontal neutrino showerswith JEM-EUSO. We also discuss the possibility to determine the flavor content of the incident neutrinoflux by taking advantage of the different characteristics of the longitudinal profiles generated by different type of neutrinos. This is of grate importance for the study of the fundamental properties of neutrinosat the highest energies. Regarding photons, we discuss the detectability of the cosmogenic component by JEM-EUSO and also estimate the expected upper limits on the photonfraction which can be obtained from the future JEM-EUSO data for the case in which there are no photonsin the samples.