Extraction of the KK-bar isovector scattering length from pp -> d K^+ K-bar^0 data near threshold


Abstract in English

The results of a recent experiment measuring the reaction pp -> dK^+ bar K^0 near threshold are interpreted in terms of a spectator model that encapsulates the main features of the observed K^+ bar K^0 invariant mass distribution. A chi^2 fit to this data leads to an imaginary part of the isovector scattering length in the K bar K channel of Im(a_1) = -(0.63 pm 0.24) fm. We then use the Flatte representation of the scattering amplitude to infer a value Re(a_1) = -(0.02 pm 0.02) fm for the real part under the assumption that scaling is approximately satisfied. We show further that it is not possible to exclude the effects of pi^+eta to K^+ bar K^0 channel coupling within the context of our model.

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