Trapping of Σ+ hyperons in nuclei

Abstract

The nuclear capture of K− studied by FINUDA discovered a puzzling low momentum component in the spectrum of final Σ+ hyperon. This component is interpreted here as the effect of Gamov state formed by the hyperon. Such state is quasi-localized in space with a radius in between the hyper-nuclear and the hyper-atomic radius. Experimental and theoretical consequences of this discovery are studied.