Triangle singularity in the gamma p -> p pi(0)eta reaction ??

The gamma p -> p pi(0)eta reaction has been studied with the CBELSA/TAPS detector system to search for experimental evidence for triangle singularities. Kinematically these singularities exist in the decay chain Delta* -> eta Delta(1232) -> eta pi(0)p but do not show an experimental effect because of the weakness of the pi(0)- eta interaction at low root s near threshold far below the a(0)(980) resonance.