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Field Redefinitions at Finite Density

R. J. Furnstahl·H. -W. Hammer·Negussie Tirfessa
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Abstract

The apparent dependence of nuclear matter observables on off-shell properties of the two-nucleon potential is re-examined in the context of the effective field theory (EFT) approach. Finite density (thermodynamic) observables are invariant under field redefinitions, which extends the well-known theorem about the invariance of S-matrix elements. Simple examples demonstrate how field redefinitions can shift contributions between purely off-shell two-body interactions and many-body forces, leaving both scattering and finite-density observables unchanged. If only the transformed two-body potentials are kept, however, the nuclear matter binding curves will depend on the off-shell part (generating ``Coester bands''). The correspondence between field redefinitions and unitary transformations, which have traditionally been used to generate ``phase-equivalent'' nucleon-nucleon potentials, is also demonstrated.

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R. J. Furnstahl, H. -W. Hammer, Negussie Tirfessa. 2000-12-05. Field Redefinitions at Finite Density. https://doi.org/10.1016/s0375-9474(00)00687-4

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