Observation of the second T= 2 state of ²⁰Ne as a compound resonance in the ¹⁹F + p reactions

Abstract

The second T = 2 state of the self-conjugate nucleus ²⁰Ne has been observed as a compound resonance in the isospin-forbidden reactions ¹⁹F(p, p), (p, n), (p, α) and (p, γ) at E_p = 5.879±0.005 MeV. The resonance width Γ_lab is 10±3 keV. The excitation energy in ²⁰Ne is 18.427±0.005 MeV in agreement with the value 18.5±0.1 MeV reported by Cerny et al. The state is found to decay through the p₀, p₁, P₂.P₃, p₄, p₅, p₇, n₀,n₁+n₂, α₀, α₁, α₂, α₄, and α₈ channels but not through the α₃, α₅, α₆, α₇, and α₉, channels within the limits of observation. The γ-transitions from the state are mainly through the cascade [E_x = 18.427; J^π = 2⁺; T = 2] → [12.25; (2)⁺; 1] → (1.63; 2⁺; 0] with no observed strength in the transitions γ₀ through γ₅. Thus, within the present limits of observation no isospin-forbidden ΔT = 2γ-transition is observed.