# Nucleon electromagnetic form factors using lattice simulations at the   physical point

**Authors:** Constantia Alexandrou, Martha Constantinou, Kyriakos Hadjiyiannakou,, Karl Jansen, Christos Kallidonis, Giannis Koutsou, and Alejandro Vaquero, Aviles-Casco

arXiv: 1706.00469 · 2017-09-21

## TL;DR

This paper reports on lattice QCD simulations of nucleon electromagnetic form factors at the physical pion mass, providing insights into their structure and comparison with experimental data.

## Contribution

The study presents new lattice QCD results for nucleon form factors at the physical point, including disconnected contributions and multiple analysis methods for ground-state extraction.

## Key findings

- Disconnected contributions are small, less than 2% of connected parts.
- Extracted nucleon radii and magnetic moments agree with experimental values.
- Results are consistent with recent lattice calculations and experimental data.

## Abstract

We present results for the nucleon electromagnetic form factors using an ensemble of maximally twisted mass clover-improved fermions with pion mass of about 130 MeV. We use multiple sink-source separations and three analysis methods to probe ground-state dominance. We evaluate both the connected and disconnected contributions to the nucleon matrix elements. We find that the disconnected quark loop contributions to the isoscalar matrix elements are small, giving an upper bound of up to 2$\%$ of the connected contribution and smaller than its statistical error. We present results for the isovector and isoscalar electric and magnetic Sachs form factors and the corresponding proton and neutron form factors. By fitting the momentum dependence of the form factors to a dipole form or to the z-expansion we extract the nucleon electric and magnetic radii, as well as, the magnetic moment. We compare our results to experiment as well as to other recent lattice QCD calculations.

## Full text

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## Figures

39 figures with captions in the complete paper: https://tomesphere.com/paper/1706.00469/full.md

## References

58 references — full list in the complete paper: https://tomesphere.com/paper/1706.00469/full.md

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Source: https://tomesphere.com/paper/1706.00469