S-factor and scattering parameters from ³He + ⁴He → ⁷Be + γ data

2018/11/19 by Xilin Zhang, Zhang, Xilin, Kenneth M. Nollett +3
Physics and Astronomy · #FOS: Physical sciences #Neutrino Physics Research #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions

paper · pdf · doi:10.48550/arxiv.1811.07611

openalex publication_date 2018/11/19 · openalex created_date 2020/01/23 · openalex updated_date 2026/07/28

Abstract

We use the next-to-leading-order (NLO) amplitude in an effective field theory (EFT) for ³He + ⁴He → ⁷Be + γ to perform the extrapolation of higher-energy data to solar energies. At this order the EFT describes the capture process using an s-wave scattering length and effective range, the asymptotic behavior of ⁷Be and its excited state, and short-distance contributions to the E1 capture amplitude. We use a Bayesian analysis to infer the multi-dimensional posterior of these parameters from capture data below 2 MeV. The total S-factor S(0)= 0.578^+0.015_-0.016 keV b at 68% degree of belief. We also find significant constraints on ³He-⁴He scattering parameters.

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