Correlation function for the $$a_0(980)$$ a 0 ( 980 )

Abstract We have conducted a model independent analysis of the $$K^+ \bar{K}^0$$ K + 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 $$K\bar{K}$$ K K ¯ interaction and the coupled channel $$\pi ^+ \eta $$ π + η . With the present large errors at small relative $$K^+\bar{K}^0$$ K + 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 $$a_0$$ a 0 resonance, $$a_0(980)$$ a 0 ( 980 ) , showing as a strong cusp close to the $$K\bar{K}$$ K K ¯ threshold. We also mention that the measurement of the $$\pi ^+ \eta $$ π + η correlation function will be essential in order to constrain more the information on $$K\bar{K}$$ K K ¯ dynamics that can be obtained from correlation functions.