New isotope Hs263

A new isotope of Hs was produced in the reaction Pb208(Fe56,n)Hs263 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 Hs263. The measured cross section was 21_-8.4⁺¹³ pb at 276.4 MeV lab frame center-of-target beam energy. Hs263 decays with a half-life of 0.74_-0.21^+0.48 ms by α-decay and the measured α-particle energies are 10.57 ± 0.06, 10.72 ± 0.06, and 10.89 ± 0.06 MeV. The experimental cross section is compared to a theoretical prediction based on the Fusion by Diffusion model [W. J. Świątecki , Phys. Rev. C 71, 014602 (2005)].