Chiral Lagrangian approach to exchange vector currents in nuclei
Abstract
Nuclear exchange vector currents applicable to any finite nucleus are calculated up to one-loop order (corresponding to next-to-next-to-leading order) in chiral perturbation theory. As an illustration of the power of the approach, we apply the formalism to the classic nuclear process n + p → d + γ at thermal energy. The exchange current correction comes out to be (4.5 ± 0.3) % in amplitude giving a predicted cross section σ = (334 ± 3) mb in excellent agreement with the experimental value (334.2 ± 0.5) mb. Together with the axial charge transitions computed previously, this result provides strong support for the power of chiral Lagrangians in nuclear physics. Certain aspects pertinent to heavy nuclei are also discussed. A by-product of our results is an open problem only partially addressed in the paper in the application of the chiral Lagrangian approach to nuclear processes that has to do with giving a physical meaning to the short-range correlations that play an important role in nuclei.
- Publication:
-
Nuclear Physics A
- Pub Date:
- February 1996
- DOI:
- 10.1016/0375-9474(95)00406-8
- arXiv:
- arXiv:nucl-th/9505017
- Bibcode:
- 1996NuPhA.596..515P
- Keywords:
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- High Energy Physics - Phenomenology;
- Nuclear Theory
- E-Print:
- 42 pages, uuencoded 7 figures (epsfig.sty included), LaTeX