Search for 2 beta decay of cadmium and tungsten isotopes: Final results of the Solotvina experiment

Final results of the double $\ensuremath{\beta}$ decay experiment, performed with the help of low background ${}^{116}{\mathrm{CdWO}}_{4}$ crystal scintillators in the Solotvina Underground Laboratory, are presented. In particular, the revised half-life value of the two-neutrino 2\ensuremath{\beta} decay of ${}^{116}\mathrm{Cd}$ has been measured as ${T}_{1/2}^{2\ensuremath{\nu}}{=2.9}_{\ensuremath{-}0.3}^{+0.4}\ifmmode\times\else\texttimes\fi{}{10}^{19}\mathrm{yr},$ and the new half-life limit on the neutrinoless $2\ensuremath{\beta}$ decay of ${}^{116}\mathrm{Cd}$ has been established as ${T}_{1/2}^{0\ensuremath{\nu}}g~1.7(2.6)\ifmmode\times\else\texttimes\fi{}{10}^{23}\mathrm{yr}$ at 90% (68%) C.L. The latter corresponds to a restriction on the neutrino mass: ${m}_{\ensuremath{\nu}}l~1.7(1.4)\mathrm{eV}$ at 90% (68%) C.L. Besides, new ${T}_{1/2}$ bounds (at the level of ${10}^{17}\char21{}{10}^{21}\mathrm{yr})$ were set for various $2\ensuremath{\beta}$ processes in ${}^{106}\mathrm{Cd},$ ${}^{108}\mathrm{Cd},$ ${}^{114}\mathrm{Cd},$ ${}^{180}\mathrm{W},$ and ${}^{186}\mathrm{W}$ nuclei.