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arXiv · hep-ph/9601285

The Chiral Coupling Constants $\lb{1}$ and $\lb{2}$ from \pipi Phase Shifts

B. Ananthanarayan·P. Büttiker
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Abstract

A Roy equation analysis of the available $ππ$ phase shift data is performed with the $I=0$ S- wave scattering length $a^0_0$ in the range predicted by the one-loop standard chiral perturbation theory. A suitable dispersive framework is developed to extract the chiral coupling constants \lb{1}, \lb{2} and yields \lb{1}$=-1.70\pm0.15$ and \lb{2}$\approx 5.0$. We remark on the implications of this determination to (combinations of) threshold parameter predictions of the three lowest partial waves.

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B. Ananthanarayan, P. Büttiker. 1996-01-17. The Chiral Coupling Constants $\lb{1}$ and $\lb{2}$ from \pipi Phase Shifts. https://doi.org/10.1103/physrevd.54.1125

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