1. Elastic scattering of 3He+4He with SONIK
- Author
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Paneru, S. N., Brune, C. R., Connolly, D., Odell, D., Poudel, M., Phillips, D. R., Karpesky, J., Davids, B., Ruiz, C., Lennarz, A., Greife, U., Alcorta, M., Giri, R., Lovely, M., Bowry, M., Delgado, M., Esker, N. E., Garnsworthy, A., Seeman, C., Machule, P., Fallis, J., Chen, A. A., Laddaran, F., Firmino, A., and Weinerman, C.
- Subjects
Nuclear Experiment ,Nuclear Theory - 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., Comment: 21 pages, 16 figures
- Published
- 2022