Measurement of Pion Proton Bremsstrahlung for Pions at 299-{MeV}

We have measured the fivefold differential cross section d/sup 5/sigma/d..cap omega../sub ..pi../d..cap omega../sub ..gamma../dE/sub ..gamma../ for the process ..pi../sup +/p..--> pi../sup +/p..gamma.. with incident pions of energy 299 MeV. The angular regions for the outgoing pions (55/sup 0/less than or equal totheta/sub lab//sup ..pi../less than or equal to95/sup 0/), and photons (theta/sub lab//sup ..gamma../ = 241/sup 0/ +- 10/sup 0/) in coplanar geometry are selected to maximize the sensitivity to the radiation from the magnetic dipole moment of the ..delta../sup ++/(1232) resonance. At low photon energies, the data agree with the soft-photon approximation to pion-proton bremsstrahlung. At forward pion angles the data agree with older data and with the latest theoretical calculations for 2.3..mu../sub p/less than or equal to..mu../sub ..delta../less than or equal to3.3..mu../sub p/. However at more backward pion angles where no data existed, the predictions fail.