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arXiv · hep-ph/9312307

Low--Energy Theorems for Weak Pion Production

V. Bernard·N. Kaiser·Ulf-G. Meißner
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Abstract

We derive novel low--energy theorems for single pion production off nucleons through the isovector axial current. We find that the $k^2$-dependence of the multipole $L_{0+}^{(+)}$ at threshold is given by the nucleon scalar form factor, namely $σ(k^2-M_π^2 ) /(3 πM_πF_π)$. The relation to PCAC results for soft pions including electroweak form factors is also clarified.

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V. Bernard, N. Kaiser, Ulf-G. Meißner. 1993-12-20. Low--Energy Theorems for Weak Pion Production. https://doi.org/10.1016/0370-2693(94)90954-7

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