1996/12/16 by Thomas R. Hemmert, Barry R. Holstein, Joachim Kambor · 6 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.55.5598
published as Phys.Rev.D55:5598-5612,1997 · 36 page standard latex file plus 4 figures
arxiv created 1996/12/16 · openalex publication_date 1997/05/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Previous calculations of the polarizabilities of the nucleon within the framework of heavy baryon chiral perturbation theory have included the contribution of the \ensuremathΔ(1232) only in its effects on various contact terms or have been performed in chiral SU(3) where systematic errors are difficult to control. Herein, we perform a corresponding calculation in chiral SU(2) wherein \ensuremathΔ(1232) is treated as an explicit degree of freedom and the expansion is taken to third order in soft momenta, the pion mass, and the quantity M_\ensuremathΔ\ensuremath-MN, collectively denoted \ensuremathε. We present the results of a systematic O(\ensuremathε3) calculation of forward Compton scattering off the nucleon, extract the electric polarizability \ensuremathαE, the magnetic polarizability \ensuremathβM, and the spin polarizability \ensuremathγ, and compare with available information from experiments and from previous calculations. Concluding with a critical discussion of our results, we point out the necessity of a future O(\ensuremathε4) calculation.