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Precise total cross-sections and invariant-mass distributions have beenmeasured for photoproduction of pion pairs off the proton producing$p\pi^0\pi^0$ and $n\pi^+\pi^0$ final states from the threshold region up to800 MeV incident photon energy. Additionally, beam helicity asymmetries havebeen measured in the second resonance region (550 MeV - 820 MeV). Theexperiment was performed at the tagged photon beam of the Mainz MAMIaccelerator with the Crystal Ball and TAPS detectors combined to give an almost4$\pi$ solid-angle electromagnetic calorimeter. The results are much moreprecise than any previous measurements and confirm the chiral perturbationtheory predictions for the threshold behavior of these reactions. In the secondresonance region, the invariant-mass distributions of meson-meson andmeson-nucleon pairs are in reasonable agreement with model predictions, butnone of the models reproduce the asymmetries for the mixed-charge channel.

Photoproduction of pi0pi0 and pi0pi+-pairs off the proton from threshold to the second resonance region