ππscattering amplitudes in the subthreshold region
| Autor: | W. B. Kaufmann, Gerald E. Hite |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | Physical Review C. 57:931-940 |
| ISSN: | 1089-490X 0556-2813 |
| DOI: | 10.1103/physrevc.57.931 |
| Popis: | $\ensuremath{\pi}\ensuremath{\pi}$ scattering amplitudes inside the subthreshold triangle $(0l~sl~\ensuremath{\Sigma}$, $0l~tl~\ensuremath{\Sigma}$, $0l~ul~\ensuremath{\Sigma}=4{\ensuremath{\mu}}^{2})$ are studied using interior dispersion relations. The dispersion integrals are evaluated above a center-of-mass energy ${W}_{\ensuremath{\pi}\ensuremath{\pi}}=0.6$ GeV by using a standard phase shift analysis and from this value down to threshold by using unitary models consistent with existing low-energy experimental data. It was found that by restricting the $s$-wave scattering lengths to lie on a ``universal curve'' all crossing properties and appropriated threshold sum rules were reasonably well satisfied. The invariant amplitudes are found to be in good qualitative agreement with the predictions of Weinberg's chiral model and its corrections derived from chiral perturbation theory. |
| Databáze: | OpenAIRE |
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