Clustering and α -capture reaction rate from ab initio symmetry-adapted descriptions of 20Ne
Abstract
We introduce a new framework for studying clustering and for calculating α partial widths using ab initio wave functions. We demonstrate the formalism for 20Ne , by calculating the overlap between the 16O+α cluster configuration and states in 20Ne computed in the a b i n i t i o symmetry-adapted no-core shell model. We present spectroscopic amplitudes and spectroscopic factors, and compare those to no-core symplectic shell-model results in larger model spaces, to gain insight into the underlying physics that drives α clustering. Specifically, we report on the α partial width of the lowest 1- resonance in 20Ne , which is found to be in good agreement with experiment. We also present first no-core shell-model estimates for asymptotic normalization coefficients for the ground state, as well as for the first excited 4+ state in 20Ne that lies in a close proximity to the α +16O threshold. This outcome highlights the importance of correlations for developing cluster structures and for describing α widths. The widths can then be used to calculate α -capture reaction rates for narrow resonances of interest to astrophysics. We explore the reaction rate for the α -capture reaction 16O(α,γ ) 20Ne at astrophysically relevant temperatures and determine its impact on simulated x-ray burst abundances.
- Publication:
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Physical Review C
- Pub Date:
- October 2020
- DOI:
- arXiv:
- arXiv:2006.11208
- Bibcode:
- 2020PhRvC.102d4608D
- Keywords:
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- Nuclear Theory;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 16 pages, 7 figures