Neutral pion photoproduction off 3H and 3He in chiral perturbation theory

We calculate electromagnetic neutral pion production off three-nucleon bound states (H-3, He-3) at threshold to leading one-loop order in the framework of chiral nuclear effective field theory. In addition, we analyze the dependence of the nuclear S-wave amplitude E0+ on the elementary neutron amplitude E-0+(pi 0n) which in the case of He-3 provides a stringent test of the prediction based on chiral perturbation theory. Uncertainties from higher order corrections are estimated. (C) 2011 Elsevier B.V. All rights reserved.