Computation of the electromagnetic pion form factor from lattice QCD in the epsilon regime

Abstract

We calculate the electromagnetic pion form factor in lattice QCD with 2+1 flavors of the dynamical overlap quarks. Up and down quark masses are set below their physical values so that the system is in the so-called epsilon regime with the small size of our lattice ~ 1.8 fm. The finite volume corrections are generally expected to be ~ 100% in the epsilon regime. We, however, find a way to automatically cancel the dominant part of them. Inserting non-zero momenta and taking appropriate ratios of the two and three point functions, we can eliminate the contribution from the zero-momentum pion mode. Then the remaining finite volume effect is a small perturbation from the non-zero modes. Our lattice data agree with this theoretical prediction and the extracted pion charge radius is consistent with the experiment.

arXiv comment16pages, 5 figures, minor corrections, references added, published by PRD

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Cited by in corpus (15)

• FLAG Review 2019
• FLAG Review 2021
• Timelike pion form factor in lattice QCD
• The Present and Future of QCD
• Pion form factor and charge radius from Lattice QCD at physical point
• Lattice Calculation of Pion Form Factor with Overlap Fermions
• The valence quark, sea, and gluon content of the pion from the parton distribution functions and the electromagnetic form factor
• The size of the pion from full lattice QCD with physical $u$, $d$, $s$ and $c$ quarks
• Light meson electromagnetic form factors from three-flavor lattice QCD with exact chiral symmetry
• The pion vector form factor from Lattice QCD at the physical point
• The scalar, vector and tensor form factors for the pion and kaon from lattice QCD
• QCD Predictions for Meson Electromagnetic Form Factors at High Momenta: Testing Factorization in Exclusive Processes
• Spin-orbit correlation and spatial distributions for spin-0 hadrons
• Extracting the electro-magnetic pion form factor from QCD in a finite volume
• Effective Field Theories and Lattice QCD