  We have conducted a model independent analysis of the $K^+ \bar{K}^0$ pair
correlation function obtained from ultra high energy $pp$ collisions, with the
aim of extracting the information encoded in it related to the $K\bar{K}$
interaction and the coupled channel $\pi^+ \eta$. With the present large errors
at small relative $K^+\bar{K}^0$ momenta, we find that the information obtained
about the scattering matrix suffers from large uncertainties. Even then, we are
able to show that the data imply the existence of the $a_0$ resonance,
$a_0(980)$, showing as a strong cusp close to the $K\bar{K}$ threshold. We also
mention that the measurement of the $\pi^+ \eta$ correlation function will be
essential in order to constrain more the information on $K\bar{K}$ dynamics
that can be obtained from correlation functions.
