COMPASS is a fixed-target experiment at CERN SPS which focused on light-quark
meson spectroscopy during the data-taking periods in 2008 and 2009. The central
exclusive production of glueball candidates is studied with a 190GeV/c proton
beam impinging on a liquid hydrogen target. We select centrally produced
systems with two pseudo-scalar mesons in the final state. The decay of this
system is decomposed in terms of partial waves, with particular attention paid
to the inherent mathematical ambiguities of the amplitude analysis. We show
that simple parametrisation are able to describe the mass dependence of the fit
results with sensible Breit-Wigner parameters.Comment: Presented at EDS Blois 2013 (arXiv:1309.5705