New broadBe8nuclear resonances

Structure ofA=7–8 nuclei with two- plus three-nucleon interactions from chiral effective field theory

“…[37]. We also note that the existence of a 2 + intruder broad resonance was confirmed in the R-matrix analysis of the reactions with 8 Be as the composite system [39]. We note that our present results for 7 Li, 7 Be, 8 Li and 8 B compare favorably with those of Ref.…”

Low-energyR-matrix fits for theLi6(d,α)HeGrineviciute1, Lamia2, Mukhamedzhanov3 et al. 2015Phys. Rev. C6050View full textAdd to dashboardCite

“…The relative width Γ (α) /Γ (p) for the 2 + subthreshold resonance at 20.1 MeV, found in [17], is significantly smaller than that given in literature [15] and obtained from the p+ 7 Li→ α + α and n+ 7 Be→ α + α reactions data. Also, the Γ α of the 2 + subthreshold resonance at 22.2 MeV obtained by Ref.…”

“…However, a single-level fit to data, as well as the fit, that includes all three aforementioned subthreshold resonances, fails for the bare 6 Li(d, α) 4 He astrophysical S factor using the suggested formal α + α channels partial widths Γ α = 0.11 MeV for the 2 + subthreshold state at 22.2 MeV (experimental total width 0.8 MeV), Γ α = 0.55 MeV for the 0 + subthreshold state at 20.2 MeV (experimental total width 0.72 MeV), and Γ α = 0.17 MeV for the 2 + subthreshold state at 20.1 MeV (experimental total width 0.88 MeV) in Ref. [17]. The fit also fails, if one includes an arbitrary background.…”

“…Also, the best fit of Ref. [17] includes an additional unknown level at 580 keV (excitation energy 22.78 MeV) with the formal Γ α = 0.04 MeV and Γ d = 0.23 MeV for the s-wave deuteron.…”

“…Γ α /Γ < 0.5 has been reported [16] for the 0 + state. Page [17] performed a many-level multichannel simultanous R-matrix fit to known α + α elastic scattering data, as well as (d, α) and other channels' data. However, a single-level fit to data, as well as the fit, that includes all three aforementioned subthreshold resonances, fails for the bare 6 Li(d, α) 4 He astrophysical S factor using the suggested formal α + α channels partial widths Γ α = 0.11 MeV for the 2 + subthreshold state at 22.2 MeV (experimental total width 0.8 MeV), Γ α = 0.55 MeV for the 0 + subthreshold state at 20.2 MeV (experimental total width 0.72 MeV), and Γ α = 0.17 MeV for the 2 + subthreshold state at 20.1 MeV (experimental total width 0.88 MeV) in Ref.…”