Resonance parameters of the first 1/2+ state in 9Be and astrophysical implications

Abstract

Spectra of the 9Be(e,e') reaction have been measured at the S-DALINAC at an electron energy E_0 = 73 MeV and scattering angles of 93° and 141° with high energy resolution up to excitation energies E_x = 8 MeV. The astrophysically relevant resonance parameters of the first excited 1/2+ state of 9Be have been extracted in a one-level approximation of R-matrix theory resulting in a resonance energy E_R = 1.748(6) MeV and width Gamma_R = 274(8) keV in good agreement with the latest 9Be(gamma,n) experiment but with considerably improved uncertainties. However, the reduced B(E1) transition strength deduced from an extrapolation of the (e,e') data to the photon point is a factor of two smaller. Implications of the new results for a possible production of 12C in neutron-rich astrophysical scenarios are discussed.

arXiv comment8 pages, 7 figures, accepted for publication in Phys. Rev. C

References in corpus (8)

• Large basis ab initio shell model investigation of 9-Be and 11-Be
• Pair decay width of the Hoyle state and carbon production in stars
• Converging sequences in the ab initio no-core shell model
• Distinction between sequential and direct three-body decays
• Above threshold s-wave resonances illustrated by the 1/2${}^{+}$ states in ${}^9$Be and ${}^9$B
• Three-body resonant radiative capture reactions in astrophysics
• Low-energy photodisintegration of 9Be and alpha + alpha + n <-> 9Be + gamma reactions at astrophysical conditions
• Electromagnetic response of light nuclei

Cited by in corpus (19)

• Unified ab initio approaches to nuclear structure and reactions
• Cross Section Measurement of 9Be(γ,n)8Be and Implications for α+α+n -> 9Be in the r-Process
• Astrophysical reaction rate for ${}^9$Be formation within a three-body approach
• Direct and sequential radiative three-body reaction rates at low temperatures
• Neutral $s$ States in Loosely Bound Nuclei
• Structure and three-body decay of ${}^9$Be resonances
• Continuum and Three-Nucleon Force Effects on 9Be Energy Levels
• ${}^9$Be elastic scattering on ${}^{208}$Pb and ${}^{27}$Al within a four-body reaction framework
• The virtual-state character of the {9}^Be 1/2^+ state in the {9}^Be(γ,n){8}^Be reaction
• Isovector and isoscalar dipole excitations in ${}^9$Be and ${}^{10}$Be studied with antisymmetrized molecular dynamics
• Photodisintegration cross section of ${}^9$Be up to 16 MeV in the $\alpha$ + $\alpha$ + n three-body model
• A reanalysis of radioisotope measurements of the ${}^9$Be$(\gamma ,n{)}^8$Be cross-section
• 9Be scattering with microscopic wave functions and the CDCC method
• Formation and decay of resonance state in ${}^9$Be and ${}^9$B nuclei. Microscopic three-cluster model investigations
• Properties of the first excited state of 9Be derived from (gamma,n) and (e,e') reactions
• A global study of ${}^9$Be + p at 2.72 A MeV
• New data acquisition system of the Lintott magnetic spectrometer at the S-DALINAC
• Momentum distributions from three-body decaying 9Be and 9B resonances
• The ${}^9$Be photodisintegration cross section within Cluster Effective Field Theory