New isotopeHs263

A new isotope of Hs was produced in the reaction $^{208}\mathrm{Pb}(^{56}\mathrm{Fe},n)^{263}\mathrm{Hs}$ at the 88-Inch Cyclotron of the Lawrence Berkeley National Laboratory. Six genetically correlated nuclear decay chains have been observed and assigned to the new isotope $^{263}\mathrm{Hs}$. The measured cross section was ${21}_{\ensuremath{-}8.4}^{+13}$ pb at 276.4 MeV lab frame center-of-target beam energy. $^{263}\mathrm{Hs}$ decays with a half-life of $0.{74}_{\ensuremath{-}0.21}^{+0.48}$ ms by $\ensuremath{\alpha}$-decay and the measured $\ensuremath{\alpha}$-particle energies are 10.57 \ifmmode\pm\else\textpm\fi{} 0.06, 10.72 \ifmmode\pm\else\textpm\fi{} 0.06, and 10.89 \ifmmode\pm\else\textpm\fi{} 0.06 MeV. The experimental cross section is compared to a theoretical prediction based on the Fusion by Diffusion model [W. J. \ifmmode \acute{S}\else \'{S}\fi{}wi\k{a}tecki et al., Phys. Rev. C 71, 014602 (2005)].