Comments on some chiral - dispersive calculations of ππ scattering
نویسنده
چکیده
We consider the (nominally) very precise ππ scattering amplitude obtained by Colangelo, Gasser and Leutwyler (CGL). We point out that the input used by CGL for energies above 1.42 GeV is clearly different from what one expects the physical amplitude to be. Moreover, the error they adscribe to the δ (0) 0 phase at 0.8 GeV, an important part of their input, is much underestimated. Then, we compare CGL results with those obtained by other authors using Roy equations, as well as with direct fits to experimental ππ data; and we also discuss two consistency tests of the CGL amplitude. The outcome of these tests is mismatch of the CGL amplitude, for several quantities by as much as 4 standard deviations.
منابع مشابه
Consistency checks of pion-pion scattering data and chiral dispersive calculations
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