Experimental status of deeply bound kaonic states in nuclei

We review recent claims of the existence of deeply bound kaonic states in nuclei. Also we study in details the (K−,p) reaction on 12C 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 πN, 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.