Taming the Pion Cloud of the Nucleon

الأصل · EN

We present a light-front determination of the pionic contribution to the nucleon self-energy, Σπ, to second-order in pion-baryon coupling constants that allows the pion-nucleon vertex function to be treated in a model-independent manner constrained by experiment. The pion mass μ dependence of Σπ is consistent with chiral perturbation theory results for small values of μ and is also linearly dependent on μ for larger values, in accord with the results of lattice QCD calculations. The derivative of Σπ with respect to μ² yields the dominant contribution to the pion content, which is consistent with the d-u difference observed experimentally in the violation of the Gottfried sum rule.