1995/08/22 by Susan Gardner, S. Gardner, C. J. Horowitz +1 · 1 citation
Chemistry · Physics and Astronomy · #Advanced NMR Techniques and Applications #Amplitude #Charge (physics) #Isospin #Meson #Nuclear physics #Nuclear physics research studies #Nucleon #Omega #Particle physics #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Quark #Symmetry breaking #Vector meson #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevc.53.1143
published as Phys.Rev.C53:1143-1153,1996 · 20 pages, revtex, 3 uuencoded PostScript figures
arxiv created 1995/08/22 · openalex publication_date 1996/03/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We compute isospin-violating meson-nucleon coupling constants and their consequent charge-symmetry-breaking (CSB) nucleon-nucleon potentials. The couplings result from evaluating matrix elements of quark currents between nucleon states in a nonrelativistic constituent quark model; the isospin violations arise from the difference in the up and down constituent quark masses. We find, in particular, that isospin violation in the omega-meson--nucleon vertex dominates the class IV CSB potential obtained from these considerations. We evaluate the resulting spin-singlet--triplet mixing angles, the quantities germane to the difference of neutron and proton analyzing powers measured in elastic n\ensuremath→-p\ensuremath→ scattering, and find them commensurate to those computed originally using the on-shell value of the \ensuremathρ-\ensuremathω mixing amplitude. The use of the on-shell \ensuremathρ-\ensuremathω mixing amplitude at q2=0 has been called into question; rather, the amplitude is zero in a wide class of models. Our model possesses no contribution from \ensuremathρ-\ensuremathω mixing at q2=0, and we find that omega-meson exchange suffices to explain the measured n-p analyzing power difference at 183 MeV. \textcopyright 1996 The American Physical Society.