Nπ -state contamination in lattice calculations of the nucleon pseudoscalar form factor
| Autor: | Oliver Bär |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Physics
Quantum chromodynamics Particle physics Chiral perturbation theory High Energy Physics::Lattice High Energy Physics::Phenomenology Nuclear Theory Momentum transfer Computer Science::Digital Libraries Pseudoscalar High Energy Physics - Lattice Lattice (order) Excited state Nuclear Experiment Nucleon |
| Zdroj: | Physical Review |
| ISSN: | 2470-0029 2470-0010 |
| DOI: | 10.1103/physrevd.100.054507 |
| Popis: | The nucleon-pion-state contribution in the QCD 3-point function of the pseudoscalar density is calculated to leading order in chiral perturbation theory. It predicts a nucleon-pion-state contamination in lattice estimates for the pseudoscalar form factor $G_{\rm P}(Q^2)$ determined with the plateau method. Depending on the momentum transfer $Q^2$ the contamination varies between -20% and +50% for a source-sink separation of 2 fm. The nucleon-pion-state contamination also causes violations in the generalized Goldberger-Treiman relation among the pseudoscalar and the axial nucleon form factors, the dominant source being the nucleon-pion-state contamination in the induced pseudoscalar form factor $\tilde{G}_{\rm P}(Q^2)$. Comparing the chiral perturbation theory predictions with lattice results of the PACS collaboration we find reasonable agreement even for source-sink separations as small as 1.3 fm. Comment: 22 pages, 9 figures. Revised version: Minor changes in section III and IV, typos corrected, references added, results and conclusions unchanged. Matches version published in Phys. Rev. D. arXiv admin note: text overlap with arXiv:1812.09191 |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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