Virtual photons in the pion form factors and the energy-momentum tensor

We evaluate the vector and scalar form factor of the pion in the presence o f virtual photons at next-to-leading order in two-flavor chiral perturbatio n theory. We also consider the scalar and tensor pion form factors of the e nergy-momentum tensor. We find that the intrinsic electromagnetic correctio ns are very small for the vector as well as the charged pion scalar form fa ctor. The scalar radius of the neutral pion is reduced by two percent. We p erform infrared regularization by considering electron-positron annihilatio n into pions and the decay of a light Higgs boson into a pion pair. We disc uss the detector resolution dependent contributions to the various form fac tors and pion radii. (C) 2000 Elsevier Science B.V. All rights reserved.