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Proton-$^{3}$He elastic scattering at low energies

B. M. Fisher·C. R. Brune·H. J. Karwowski·D. S. Leonard·E. J. Ludwig·T. C. Black·M. Viviani·A. Kievsky·S. Rosati
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Abstract

We present new accurate measurements of the differential cross section $σ(θ)$ and the proton analyzing power $A_{y}$ for proton-$^{3}$He elastic scattering at various energies. A supersonic gas jet target has been employed to obtain these low energy cross section measurements. The $σ(θ)$ distributions have been measured at $E_{p}$ = 0.99, 1.59, 2.24, 3.11, and 4.02 MeV. Full angular distributions of $A_{y}$ have been measured at $E_{p}$ = 1.60, 2.25, 3.13, and 4.05 MeV. This set of high-precision data is compared to four-body variational calculations employing realistic nucleon-nucleon (NN) and three-nucleon (3N) interactions. For the unpolarized cross section the agreement between the theoretical calculation and data is good when a $3N$ potential is used. The comparison between the calculated and measured proton analyzing powers reveals discrepancies of approximately 50% at the maximum of each distribution. This is analogous to the existing ``$A_{y}$ Puzzle'' known for the past 20 years in nucleon-deuteron elastic scattering.

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B. M. Fisher, C. R. Brune, H. J. Karwowski, D. S. Leonard, E. J. Ludwig, T. C. Black, M. Viviani, A. Kievsky, S. Rosati. 2006-08-22. Proton-$^{3}$He elastic scattering at low energies. https://doi.org/10.1103/physrevc.74.034001

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