Is Cen A surrounded by tens EeV Multiplet?

Abstract

Ultra High Energy Cosmic Rays (UHECR) at GZK cut off energy (E \geq 55 EeV eV) may keep sharp or diffused directionality wherever their composition is made by nucleon or light nuclei. AUGER UHECR (2007-2010) did show a mild clustering mainly around Cen A. Two over three of the recent discovered AUGER multiplet (a dozen of events each) tail clustering at twenty EeV are pointing to primary sources very near the same UHECR crowded Cen A region. The Tens EeV tail is aligned with the same UHECR events. We foresaw such possibility as fragment tails of lightest UHECR nuclei. We discuss the relevance of this correlation within a model where UHECR are mostly lightest He like nuclei. UHECR fragment multiplet clustering aligned along higher Cen A events (at 55 EeV energy) probe and reinforce our interpretation with an a priori probability near 3 part over a hundred thousand.