Zemach and Friar radii of the proton and neutron from lattice QCD

Abstract

We present the first lattice-QCD result for the Zemach and Friar radii of the proton and neutron. Our calculation includes both quark-connected and -disconnected diagrams and assesses all sources of systematic uncertainties arising from excited-state contributions, finite-volume effects and the continuum extrapolation. At the physical point, we obtain for the proton $r_Z^p=(1.013\pm 0.010(\mathrm{stat})\pm 0.012(\mathrm{syst}))\mathrm{fm}$ and $r_F^p=(1.301\pm 0.012(\mathrm{stat})\pm 0.014(\mathrm{syst}))\mathrm{fm}$. These numbers suggest small values of the Zemach and Friar radii of the proton, but are compatible with most of the experimental studies.

13 pages, 2 figures; v2: significantly extended version including, in addition to the Zemach radius of the proton, results for the Friar radius of the proton as well as for the Zemach and Friar radii of the neutron; v3: typos fixed, matches published version

References in corpus (18)

• Leading hadronic contribution to the muon magnetic moment from lattice QCD
• FLAG Review 2021
• Ab initio calculation of the neutron-proton mass difference
• Simulation of QCD with N_f=2+1 flavors of non-perturbatively improved Wilson fermions
• Dispersion analysis of the nucleon form factors including meson continua
• Model independent extraction of the proton charge radius from electron scattering
• The RMS Charge Radius of the Proton and Zemach Moments
• Parameterization and applications of the low-$Q^2$ nucleon vector form factors
• The two-photon exchange contribution to muonic hydrogen from chiral perturbation theory
• The proton structure in and out of muonic hydrogen
• Remarks on strange-quark simulations with Wilson fermions
• Comprehensive theory of the Lamb shift in light muonic atoms
• Improved information criteria for Bayesian model averaging in lattice field theory
• QED is not endangered by the proton's size
• Precision calculation of the electromagnetic radii of the proton and neutron from lattice QCD
• Electromagnetic form factors of the nucleon from $N_f=2+1$ lattice QCD
• Measurement of the muon transfer rate from muonic hydrogen to oxygen in the range 70-336 K
• Breakdown of the expansion of finite-size corrections to the hydrogen Lamb shift in moments of charge distribution

Cited by in corpus (3)

• FLAG Review 2024
• Laser Excitation of Muonic 1S Hydrogen Hyperfine Transition: Effects of Multi-pass Cell Interference
• Proton and neutron electromagnetic form factors from lattice QCD in the continuum limit