标题： 超子的电磁衰变（II） 显示英文标题

标题： Electromagnetic Decays of Hyperons (II)

摘要： 在一种将π介子和K介子场当作微扰处理的手征袋模型中计算了激发态负宇称超子的质量。我们还计算了 $\lama$ 和 $\lamb$ 的强子衰变宽度以及最轻的激发态超子 $I=0$ 到介子-重子通道的耦合常数，并讨论了介子-重子衰变通道的色散效应如何影响激发态超子的质量。在同一模型中计算了两个最轻激发态超子到基态 $\lamz$ 和 $\sigz$ 的电磁衰变宽度的介子云修正，发现这些修正较小。我们的结果进一步支持了这样一种观点：这些超子辐射衰变宽度的预测是对各种强子夸克模型的一个极好的检验。 显示英文摘要

摘要： Excited negative parity hyperon masses are calculated in a chiral bag model in which the pion and the kaon fields are treated as perturbations. We also calculate the hadronic widths of $\lama$ and $\lamb$ as well as the coupling constants of the lightest $I=0$ excited hyperon to the meson-baryon channels, and discuss how the dispersive effects of the hadronic meson-baryon decay channels affect the excited hyperon masses. Meson cloud corrections to the electromagnetic decay widths of the two lightest excited hyperons into ground states $\lamz$ and $\sigz$ are calculated within the same model and are found to be small. Our results strengthen the argument that predictions of these hyperon radiative decay widths provide an excellent test for various quark models of hadrons.