Elastic scattering of 3He+4He with SONIK

S. N. Paneru; C. R. Brune; D. Connolly; D. Odell; M. Poudel; D. R. Phillips; J. Karpesky; B. Davids; C. Ruiz; A. Lennarz; U. Greife; M. Alcorta; R. Giri; M. Lovely; M. Bowry; M. Delgado; N. E. Esker; A. Garnsworthy; C. Seeman; P. Machule; J. Fallis; A. A. Chen; F. Laddaran; A. Firmino; C. Weinerman

arXiv · 2211.14641

Elastic scattering of 3He+4He with SONIK

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Abstract

Measurements of the elastic scattering cross section of 3He and 4He are important in order to improve constraints on theoretical models of 4He(3He,g)7Be, a key reaction in Big Bang nucleosynthesis and solar neutrino production. The astrophysical S-factor for this reaction is a significant source of uncertainty in the standard solar-model prediction of the 7Be and 8B solar neutrino fluxes. The elastic scattering measurements reported in the literature do not extend to low energies and lack proper uncertainty quantification. A new measurement of the 4He(3He,3He)4He reaction has been made at center-of-mass energies Ec.m. = 0.38-3.13 MeV using the Scattering of Nuclei in Inverse Kinematics (SONIK) scattering chamber: a windowless, extended gas target surrounded by an array of 30 collimated silicon charged particle detectors situated at TRIUMF. This is the first elastic scattering measurement of 3He+4He made below 500 keV and it has greater angular range and better precision than previous measurements. The elastic scattering data were analyzed using both R-matrix and Halo Effective Field Theory (Halo EFT) frameworks, and values of the s-wave scattering length and effective range were extracted. The resulting improvement in knowledge of the s-wave effective-range function at low energies will reduce the overall uncertainty in S34 at solar energies.

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S. N. Paneru, C. R. Brune, D. Connolly, D. Odell, M. Poudel, D. R. Phillips, J. Karpesky, B. Davids, C. Ruiz, A. Lennarz, U. Greife, M. Alcorta, R. Giri, M. Lovely, M. Bowry, M. Delgado, N. E. Esker, A. Garnsworthy, C. Seeman, P. Machule, J. Fallis, A. A. Chen, F. Laddaran, A. Firmino, C. Weinerman. 2022-11-26. Elastic scattering of 3He+4He with SONIK. https://arxiv.org/abs/2211.14641

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