Resonances in 14C observed in the 4He(10Be ,α )10Be reaction

The α (¹⁰Be,α )¹⁰Be resonant scattering reaction has been measured at nine ¹⁰Be beam energies from 25 to 48 MeV, scanning out resonances in ¹⁴C from excitation energies of 13 to 24 MeV. Angular distribution measurements were used to assign the spin and parity of 5^- to resonances at E_x=18.82 (2 ) and 19.67(2) MeV and 6⁺ at E_x=20.80 (2 ) MeV. The data also strongly indicate a 3^- resonance at 17.32(2) MeV. The systematic uncertainty on the excitation energies is 175 keV. An R -matrix analysis has been performed for the excitation energy range 16.5 to 22 MeV. The data are discussed in terms of cluster bands in ¹⁴C.