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The anomalous process gamma pi -> pi pi to two loops

Torben Hannah
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Abstract

The amplitude for the anomalous process gamma pi -> pi pi is evaluated to two loops in the chiral expansion by means of a dispersive method. The two new coupling constants that enter at this order are estimated via sum rules derived from a non-perturbative chiral approach. With these coupling constants fixed, the numerical results are given and compared with the available experimental information.

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Torben Hannah. 2001-02-16. The anomalous process gamma pi -> pi pi to two loops. https://doi.org/10.1016/s0550-3213(00)00641-6

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