Observation of muon inner bremsstrahlung in deep-inelastic neutrino scattering

In a neutrino bubble-chamber experiment with a mean event energy of 90 GeV, clear evidence is observed for muon inner bremsstrahlung. The corrected rate, for gamma rays with E/sub ..gamma../>1 GeV and within 32 mrad of the muon direction, is 0.027 +- 0.005 per charged current event. Comparison with QED calculations is discussed.