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n+p -> d+gamma for Big-Bang Nucleosynthesis

Jiunn-Wei Chen·Martin J. Savage
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Abstract

The cross section for n+p -> d+gamma is calculated at energies relevant to big bang nucleosynthesis using the recently developed effective field theory that describes the two-nucleon sector. The E1 amplitude is computed up to NNNLO and depends only upon nucleon-nucleon phase shift data. In contrast, the M1 contribution is computed up to NLO, and the four-nucleon-one-magnetic-photon counterterm that enters is determined by the cross section for cold neutron capture. The uncertainty in the calculation for nucleon energies up to E ~ 1 MeV is estimated to be < 4%.

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BibTeXRIS

Jiunn-Wei Chen, Martin J. Savage. 1999-07-09. n+p -> d+gamma for Big-Bang Nucleosynthesis. https://doi.org/10.1103/physrevc.60.065205

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