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Radiative Neutron-Proton Capture in Effective Chiral Lagrangians

Tae-Sun Park·Dong-Pil Min·Mannque Rho
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Abstract

We calculate the cross-section for the thermal $n+p\rightarrow d+γ$ process in chiral perturbation theory to next-to-next-to-leading order using heavy-fermion formalism. The exchange current correction is found to be $(4.5\pm 0.3)~\%$ in amplitude and the chiral perturbation at one-loop order gives the cross section $σ_{th}^{np}=(334\pm 2)\ {\mbox mb}$ which is in agreement with the experimental value $(334.2\pm 0.5)\ {\mbox mb}$. Together with the axial charge transitions, this provides a strong support for the power of chiral Lagrangians for nuclear physics.

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Tae-Sun Park, Dong-Pil Min, Mannque Rho. 1994-12-16. Radiative Neutron-Proton Capture in Effective Chiral Lagrangians. https://doi.org/10.1103/physrevlett.74.4153

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