Unmasking the tail of the cosmic ray spectrum

A re-examination of the energy cosmic ray spectrum above 1020 eV is presented. The overall data-base provides evidence, albeit still statistically limited, that non-nucleon primaries could be present at the end of the spectrum. In particular, the possible appearance of superheavy nuclei (seldom discussed in the literature) is analysed in detail.Facultad de Ciencias Exacta