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

A search for the muon catalyzed fusion reaction dd --> ^4He +\gamma in the dd\mu 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 dd\mu state J=1 was obtained at the level n_{\gamma}\leq 2\times 10^{-5} per one fusion.Comment: 9 pages, 3 Postscript figures, submitted to Phys. At. Nuc

The explanation of unexpected temperature dependence of the muon catalysis in solid deuterium

It is shown that due to the smallness of the inelastic cross-section of the $d\mu$-atoms scattering in the crystal lattice at sufficiently low temperatures the $dd\mu$-mesomolecules formation from the upper state of the hyperfine structure $d\mu (F=3/2)$ starts earlier than the mesoatoms thermolization. It explains an approximate constancy of the $dd\mu$-mesomolecule formation rate in solid deuterium.Comment: 6 pages, 2 jpeg-figure