Measurement of the K$\_{s}^{0}\rightarrow\pi^{+}\pi^{-}\gamma$

From a study of 70000 K/sup 0/ decays in the CERN 2m hydrogen bubble chamber, the rate for K/sub S//sup 0/ to pi /sup +/ pi /sup -/ gamma for different custs in the gamma momentum has been estimated. The results are in good agreement with inner bremsstrahlung on K/sub S //sup 0/ to pi /sup +/ pi /sup -/. For gamma momentum in the K/sup 0/ c.m. greater than 50 MeV/c, the branching ratio: Gamma (K/sub S/ to pi /sup +/ pi /sup -/ gamma , k>50 MeV/c)/ Gamma (K/sub S/ to pi /sup +/ pi /sup -/)=(2.8+or-0.6)*10/sup -3/ has been obtained. This leads to an estimate for the direct gamma emission process: Gamma (K/sub S/ to pi /sup +/ pi /sup -/ gamma direct)/ Gamma (K/sub S/ to pi /sup +/ pi /sup -/)=(0.3+or-0.6)*10/sup -3/. (12 refs).