Search for the Radiative Capture d+d->^4He+gamma Reaction from the ddmu Muonic Molecule State

A search for the muon catalyzed fusion reaction dd --> ^4He +gamma in the ddmu muonic molecule was performed using the experimental mu CF installation TRITON and NaI(Tl) detectors for gamma-quanta. The high pressure target filled with deuterium at temperatures from 85 K to 800 K was exposed to the negative muon beam of the JINR phasotron to detect gamma-quanta with energy 23.8 MeV. The first experimental estimation for the yield of the radiative deuteron capture from the ddmu state J=1 was obtained at the level n_{gamma}leq 2times 10^{-5} per one fusion.