Ambiguities of the single spin observables in a truncated partial wave expansion for photoproduction of pseudoscalar mesons

The ambiguity problem in the truncated partial wave analysis of pseudoscalar meson photoproduction with suppressed t-channel exchanges is investigated. More precisely, the focus is set to ambiguities of the four single spin observables, $\sigma_0$, $\Sigma$, $T$ and $P$. For this purpose, the approach and formalism already worked out by Omelaenko in 1981 is revisited in this work. A numerical study using multipoles of the PWA solution MAID2007 shows how, for ideal circumstances, only one additional double polarization observable can resolve all ambiguities.