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arXiv · 1103.4434

Spin Polarization in $γd \to \vec{n}p$ at Low Energies with a Pionless Effective Field Theory

S. -I. Ando·Y. -H. Song·C. H. Hyun·K. Kubodera
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Abstract

With the use of pionless effective field theory including dibaryon fields, we study the $γd \to \vec{n} p$ reaction for the laboratory photon energy $E_γ^{lab}$ ranging from threshold to 30 MeV. Our main goal is to calculate the neutron polarization $P_{y'}$ defined as $P_{y'} = (σ_+ - σ_-)/(σ_+ + σ_-)$, where $σ_+$ and $σ_-$ are the differential cross sections for the spin-up and spin-down neutrons, respectively, along the axis perpendicular to the reaction plane. We also calculate the total cross section as well as the differential cross section $σ(θ)$, where $θ$ is the colatitude angle. Although the results for the total and differential cross sections are found to agree reasonably well with the data, the results for $P_{y'}$ show significant discrepancy with the experiment. We comment on this discrepancy.

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S. -I. Ando, Y. -H. Song, C. H. Hyun, K. Kubodera. 2011-06-01. Spin Polarization in $γd \to \vec{n}p$ at Low Energies with a Pionless Effective Field Theory. https://doi.org/10.1103/physrevc.83.064002

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