Dispersion relations for γ ∗ γ ∗ → ππ: helicity amplitudes, subtractions, and anomalous thresholds
Abstract We present a comprehensive analysis of the dispersion relations for the doubly-virtual process γ ∗ γ ∗ → ππ. Starting from the Bardeen-Tung-Tarrach amplitudes, we first derive the kernel functions that define the system of Roy-Steiner equations for the partial-wave helicity amplitudes. We t...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2019-07-01
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| Series: | Journal of High Energy Physics |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1007/JHEP07(2019)073 |