A dispersion theoretical approach to the threshold amplitudes of pion photoproduction

被引：41

作者：

Hanstein, O

Drechsel, D

Tiator, L

机构：

[1] Institut für Kernphysik, Universität Mainz

来源：

PHYSICS LETTERS B | 1997年 / 399卷 / 1-2期

关键词：

pion photoproduction; dispersion relations; low energy theorems; threshold amplitudes;

D O I：

10.1016/S0370-2693(97)00272-4

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We give predictions for the partial wave amplitudes of pion photoproduction near threshold by means of dispersion relations at fixed t. The free parameters of this approach are determined by a fit to experimental data in the energy range 160 MeV less than or equal to E-gamma less than or equal to 420 MeV. The observables near threshold are found to be rather sensitive to the amplitudes in the resonance region, in particular to the Delta (1232) and N*(1440). We obtain a good agreement with the existing threshold data for both charged and neutral pion production. Our predictions also agree well with the results of chiral perturbation theory, except for neutral pion production off the neutron. (C) 1997 Elsevier Science B.V.

引用

页码：13 / 21

页数：9

共 38 条

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