The incompleteness of complete pseudoscalar-meson photoproduction

Understand

[Background] A complete set is a minimum set of observables which allows one to determine the underlying reaction amplitudes unambiguously.

• Pseudoscalar-meson photoproduction from the nucleon is characterized by four such amplitudes and complete sets involve single- and double-polarization observables.
• [Purpose] Identify complete sets of observables, and study how measurements with finite error bars impact their potential to determine the reaction amplitudes unambiguously.
• [Method] The authors provide arguments to employ the transversity representation in order to determine the amplitudes in pseudoscalar-meson photoproduction.