Experimental status of deeply bound kaonic states in nuclei

TL;DR

This paper critically reviews claims of deeply bound kaonic states in nuclei, analyzing experimental data with comprehensive simulations that suggest a standard shallow optical potential suffices to explain observations.

Contribution

It provides a detailed Monte Carlo simulation including various reaction mechanisms, challenging previous claims of deeply bound states with a standard potential model.

Findings

Additional reaction mechanisms explain the observed spectra.

Standard shallow optical potential is sufficient to account for data.

Deeply bound kaonic states are not necessary to interpret the results.

Abstract

We review recent claims of the existence of deeply bound kaonic states in nuclei. Also we study in details the (K-,p) reaction on C12 with 1 GeV/c momentum kaon beam, based on which a deep kaon nucleus optical potential was claimed in [1]. In our Monte Carlo simulation of this reaction we include not only the quasi-elastic K- p scattering, as in [1], but also K- absorption by one and two nucleons followed by the decay of the hyperon in pi N, which can also produce strength in the region of interest. The final state interactions in terms of multiple scattering of the K-, p and all other primary particles on their way out of the nucleus is also considered. We will show that all these additional mechanisms allow us to explain the observed spectrum with a "standard" shallow kaon nucleus optical potential obtained in chiral models. [1] T. Kishimoto et al., Prog. Theor. Phys. 118, 181 (2007).