Study of pi-p-->pi-eta p and pi-p-->pi-eta eta p at sqrt(s)_s13_s178201_s19=_s13_s178201_s1918.9_s13_s178201_s19GeV with the COMPASS experiment

Abstract

The COMPASS experiment at CERN studies diffractively produced states in the light quark sector with unprecedented statistics. The observation of f0(1500)/f2_s13_s178242_s19(1525) decaying to _s13_s17951_s19_s13_s17951_s19 in 2008 data with incoming negative pion beam at 190 GeV/c poses the question whether it is produced centrally or formed by the decay of a heavier diffractively produced _s13_s17960_s191(1800)/_s13_s17960_s192(1880). To decide, a dedicated amplitude analysis which includes different production mechanisms is formulated and compared with one which was used to fit centrally produced resonances including f0(1500) by the WA102 experiment. Unbinned mass_s13_s178208_s19dependent log_s13_s178208_s19likelihood fitting methods may serve to solve the ambiguities which are present in binned, mass_s13_s178208_s19independent partial wave analyses.