## 抄録

We reassess the validity of the current-algebra based low-energy theorem of pion photoproduction on the nucleon using the Skyrme model. We find that one of the off-shell electromagnetic form factors of the nucleon exhibits infrared divergence in the chiral limit. This contribution introduces an additional term to the threshold amplitude predicted by the low-energy theorem. The emergence of the additional term indicates an unavoidable necessity of off-shell form factors in deriving the low-energy theorem. In the case of neutral pion production, the new contribution to the threshold amplitude is found to be comparable in magnitude to the low-energy theorem's prediction and has the opposite sign. In the charged pion production channels, the correction to the theorem is shown to be relatively small.

本文言語 | English |
---|---|

ページ（範囲） | 443-471 |

ページ数 | 29 |

ジャーナル | Nuclear Physics, Section A |

巻 | 592 |

号 | 4 |

DOI | |

出版ステータス | Published - 1995 10月 2 |

外部発表 | はい |

## ASJC Scopus subject areas

- 核物理学および高エネルギー物理学