### Abstract

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.

Original language | English |
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Pages (from-to) | 443-471 |

Number of pages | 29 |

Journal | Nuclear Physics, Section A |

Volume | 592 |

Issue number | 4 |

DOIs | |

Publication status | Published - 1995 Oct 2 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Nuclear and High Energy Physics

### Cite this

*Nuclear Physics, Section A*,

*592*(4), 443-471. https://doi.org/10.1016/0375-9474(95)00325-U

**The low-energy theorem of pion photoproduction using the Skyrme model.** / Ikehashi, Tamio; Ohta, Koichi.

Research output: Contribution to journal › Article

*Nuclear Physics, Section A*, vol. 592, no. 4, pp. 443-471. https://doi.org/10.1016/0375-9474(95)00325-U

}

TY - JOUR

T1 - The low-energy theorem of pion photoproduction using the Skyrme model

AU - Ikehashi, Tamio

AU - Ohta, Koichi

PY - 1995/10/2

Y1 - 1995/10/2

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=58149320284&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=58149320284&partnerID=8YFLogxK

U2 - 10.1016/0375-9474(95)00325-U

DO - 10.1016/0375-9474(95)00325-U

M3 - Article

VL - 592

SP - 443

EP - 471

JO - Nuclear Physics A

JF - Nuclear Physics A

SN - 0375-9474

IS - 4

ER -