Formulate amplitude model with t-channel effects

[redeboer]

The notebooks introduced #17 and #18 only build a simple decay chain model, constructing $p\gamma$ as a 'virtual' state (s channel) with single, fixed quantum numbers. This is not feasible for GlueX, where t channels dominate.

For this reason, a second set of project notebooks is developed in parallel that build the amplitude through pure SymPy (#13, see also https://github.com/ComPWA/RUB-EP1-AG/issues/144). This does not use an amplitude builder for the decay chain, but should offer the flexibility to build up a correct formulation of the production mechanism.
Additional constraints can be formulated from the final state in order to further simplify the amplitude model. As suggested by @bgrube, a nice example of this can be found in GlueX-doc-4788.

[shenvitor]

The notebooks introduced #17 and #18 only build a simple decay chain model, constructing pγ as a 'virtual' state (s channel) with single, fixed quantum numbers. This is not feasible for GlueX, where t channels dominate.

For this reason, a second set of project notebooks is developed in parallel that build the amplitude through pure SymPy (#13, see also ComPWA/RUB-EP1-AG#144). This does not use an amplitude builder for the decay chain, but should offer the flexibility to build up a correct formulation of the production mechanism. Additional constraints can be formulated from the final state in order to further simplify the amplitude model. As suggested by @bgrube, a nice example of this can be found in GlueX-doc-4788.

"Pomeron Exchange" 🤔

[shenvitor]

Area for relevant literatures that are interesting or maybe useful (updating):

$\Lambda$ related

Coupled-channel analysis for ϕ photoproduction with Λ(1520)

** Application of the single-channel, single-energy amplitude and partial-wave analysis method to 𝐾+⁢Λ photoproduction

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s & t & u channel related

Amplitude- and truncated partial-wave analyses combined: A single-channel method for extracting photoproduction multipoles directly from measured data

Nucleon and resonances in photoproduction

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$\pi$ related

Pion photoproduction in a dynamical coupled-channels model