Using the FOCUS spectrometer (experiments 687 and 831 at Fermilab) we confirm the existence of a diffractively photoproduced enhancement in K^+K^- at 1750 MeV/c² with nearly 100 times the statistics of previous experiments. We also observe a narrow dip structure at 1. 9 GeV/c2 in a study of diffractive photoproduction of the 3π^+3π^- final state.
L. et al. (Tue,) studied this question.