  We study the (K-,p) reaction on nuclei with a 1 GeV/c momentum kaon beam,
paying a special attention at the region of emitted protons having kinetic
energy above 600 MeV, which was used to claim a deeply attractive kaon nucleus
optical potential. Our model describes the nuclear reaction in the framework of
a local density approach and the calculations are performed following two
different procedures: one is based on a many-body method using the Lindhard
function and the other one is based on a Monte Carlo simulation. While both
procedures coincide when it comes to consider the contribution of kaon
quasi-elastic scattering, the simulation method offers more flexibility since
it allows us to account for other processes which also contribute to the proton
spectra, such as K- absorption by one and two nucleons producing hyperons. The
simulation also considers final state interactions in terms of multiple
scattering of the K-, p and all other primary and secondary particles on their
way out of the nucleus, as well as the weak decay of the produced hyperons into
(pi N). We find that this kaon in-flight reaction is not well suited to
determine the kaon optical potential due, essentially, to the limited
sensitivity of the cross section to its strength, but also to unavoidable
uncertainties in the contribution from other processes. We also simulate the
experimental requirement of having, together with the energetic proton, at
least one charged particle detected in the decay counter surrounding the
target, and find that the shape of the original cross section is appreciably
distorted. We conclude that the new mechanisms, not considered in the analysis
of the original experiment, allow us to explain the observed spectrum with the
shallow kaon nucleus optical potential obtained in chiral models.
