Extraction of the KK¯ isovector scattering length from pp→dK+K¯0 data near threshold

The results of a recent experiment measuring the reaction pp→dK+K¯0 near threshold are interpreted in terms of a spectator model that encapsulates the main features of the observed K+K¯0 invariant mass distribution. A χ2 fit to this data leads to an imaginary part of the isovector scattering length in the KK¯ channel of Im(a1)=−(0.63±0.24)fm. We then use the Flatté representation of the scattering amplitude to infer a value Re(a1)=−(0.02±0.02)fm for the real part under the assumption that scaling [V. Baru, J. Haidenbauer, C. Hanhart, A. Kudryavtsev, U.G. Meissner, Eur. Phys. J. A 23 (2005) 523] is approximately satisfied. We show further that it is not possible to exclude the effects of π+η to K+K¯0 channel coupling within the context of our model.