$N\pi$-states and the projection method for the nucleon axial and pseudoscalar form factors

Abstract

The RQCD collaboration proposed a projection method to remove the excited state contamination in lattice OCD calculations of nuclear form factors. The effectiveness of this method in removing the two-particle nucleon-pion-state contamination is examined using chiral perturbation theory. It is shown that the projection method has practically no impact in the calculation of the axial and induced pseudoscalar form factors. In the pseudoscalar form factor the projection method strongly enhances the nucleon-pion-state contamination. The generalized Goldberger-Treiman relation is satisfied even though large nucleon-pion-state contaminations are present in individual form factors. Therefore, the projection method is not a solution to the excited state problem in nucleon form factor calculations.

arXiv comment17 pages, 5 figures

References in corpus (19)

• Nucleon isovector couplings from $N_f=2$ lattice QCD
• Axial Vector Form Factors of the Nucleon from Lattice QCD
• Axial Vector Form Factors from Lattice QCD that Satisfy the PCAC Relation
• Nucleon form factors on a large volume lattice near the physical point in 2+1 flavor QCD
• Chiral perturbation theory for gradient flow observables
• Lattice QCD and Neutrino-Nucleus Scattering
• $N\pi$-state contamination in lattice calculations of the nucleon axial form factors
• Solving the PCAC puzzle for nucleon axial and pseudoscalar form factors
• Nucleon-pion-state contribution in lattice calculations of the nucleon charges $g_A,g_T$ and $g_S$
• Nucleon-pion-state contribution to nucleon two-point correlation functions
• Nucleon form factors from quenched lattice QCD with domain wall fermions
• $N\pi$-state contamination in lattice calculations of the nucleon pseudoscalar form factor
• Chiral perturbation theory and nucleon-pion-state contaminations in lattice QCD
• Chiral extrapolation of nucleon wave function normalization constants
• Multi-hadron-state contamination in nucleon observables from chiral perturbation theory
• Nucleon-pion-state contribution in lattice calculations of moments of parton distribution functions
• Nucleon Axial and Electromagnetic Form Factors
• Three-particle $N\pi \pi$ state contribution to the nucleon two-point function in lattice QCD
• Nucleon structure from 2+1 flavor lattice QCD near the physical point

Cited by in corpus (10)

• Nucleon axial structure from lattice QCD
• Towards grounding nuclear physics in QCD
• Nucleon axial-vector and pseudoscalar form factors, and PCAC relations
• Toward $N$ to $N\pi$ matrix elements from lattice QCD
• $N\pi$-state contamination in lattice calculations of the nucleon electromagnetic form factors
• Excited states in nucleon structure calculations
• Axial and pseudoscalar form factors from charged current quasielastic neutrino-nucleon scattering
• Detailed analysis of excited state systematics in a lattice QCD calculation of $g_A$
• Investigation of pion-nucleon contributions to nucleon matrix elements
• Elastic Nucleon-Pion scattering amplitudes in the $\Delta$ channel at physical pion mass from Lattice QCD