Campos, A. H.Lengruber, L. L.Rosenfeld, Rogério [UNESP]Reis, H. C.Sato, R.2014-05-202014-05-202002-10-30Modern Physics Letters A. Singapore: World Scientific Publ Co Pte Ltd, v. 17, n. 33, p. 2179-2188, 2002.0217-7323http://hdl.handle.net/11449/23038Top-down models for the origin of ultra high energy cosmic rays (UHECR's) propose that these events are the decay products of relic superheavy metastable particles, usually called X particles. These particles can be produced in the reheating period following the inflationary epoch of the early Universe. We obtain constraints on some parameters such as the lifetime and direct couplings of the X-particle to the inflaton field from the requirement that they are responsible for the observed UHECR flux.2179-2188enghigh energy cosmic raysinflationreheatingArtigo10.1142/S0217732302008915WOS:000179800600004Acesso restrito