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Covariant propagator of the Rarita-Schwinger field in the nuclear medium

C. L. Korpa·A. E. L. Dieperink
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Abstract

A formalism for representing the fully relativistic propagator of the Rarita-Schwinger field in the nuclear medium is developed. Using a convenient basis for expanding the propagator, or the self energy, it is shown that they can be represented by 40 energy and momentum dependent quantities which can be combined into a 2x2 and a 6x6 matrix. In this way calculations reduce to matrix multiplication. Using the presented formalism the full relativistically covariant contribution of the pion-nucleon loop to the isobar self energy and propagator in isospin-symmetric spin-saturated nuclear medium is computed. Utilizing this propagator the photoabsorption cross-section on in-medium nucleons in the isobar region is calculated and the result compared with experimental data.

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C. L. Korpa, A. E. L. Dieperink. 2005-03-29. Covariant propagator of the Rarita-Schwinger field in the nuclear medium. https://doi.org/10.1103/physrevc.70.015207

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