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Title: Effective field theory analysis of 3 He–α scattering data
Abstract We treat low-energy 3 He– α elastic scattering in an effective field theory (EFT) that exploits the separation of scales in this reaction. We compute the amplitude up to next-to-next-to-leading order, developing a hierarchy of the effective-range parameters (ERPs) that contribute at various orders. We use the resulting formalism to analyse data for recent measurements at center-of-mass energies of 0.38–3.12 MeV using the scattering of nuclei in inverse kinematics (SONIK) gas target at TRIUMF as well as older data in this energy regime. We employ a likelihood function that incorporates the theoretical uncertainty due to truncation of the EFT and use Markov chain Monte Carlo sampling to obtain the resulting posterior probability distribution. We find that the inclusion of a small amount of data on the analysing power A y is crucial to determine the sign of the p-wave splitting in such an analysis. The combination of A y and SONIK data constrains all ERPs up to O ( p 4 ) in both s- and p-waves quite well. The asymptotic normalisation coefficients and s-wave scattering length are consistent with a recent EFT analysis of the capture reaction 3 He( α , γ ) 7 Be.  more » « less
Award ID(s):
2020275 2004601
PAR ID:
10331366
Author(s) / Creator(s):
;
Date Published:
Journal Name:
Journal of Physics G: Nuclear and Particle Physics
Volume:
49
Issue:
4
ISSN:
0954-3899
Page Range / eLocation ID:
045102
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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