TY - JOUR

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

AU - Ikehashi, Tamio

AU - Ohta, Koichi

N1 - Funding Information:
We would like to thank A. Hashimoto for a help in numerical calculations. One of the authors (T.I.) is grateful to Prof. M. Ichimura for various supports and useful comments. This work is supported by the Research fellowships of the Japan Society for the Promotion of Science for Young Scientists.
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.

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.

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

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

M3 - Article

AN - SCOPUS:58149320284

VL - 592

SP - 443

EP - 471

JO - Nuclear Physics A

JF - Nuclear Physics A

SN - 0375-9474

IS - 4

ER -