Nucleon Sigma Terms with $N_f=2+1$ O($a$)-improved Wilson fermions

Abstract

We present a lattice-QCD based analysis of the nucleon sigma terms using gauge ensembles with $N_f=2+1$ flavors of $\mathcal{O}(a)$-improved Wilson fermions, with a complete error budget concerning excited-state contaminations, the chiral interpolation as well as finite-size and lattice spacing effects. We compute the sigma terms determined directly from the matrix elements of the scalar currents. The chiral interpolation is based on SU(3) baryon chiral perturbation theory using the extended on-mass shell renormalization scheme. For the pion nucleon sigma term, we obtain ${\sigma }_{\pi N}=(43.7\pm 3.6)$ MeV, where the error includes our estimate of the aforementioned systematics. The tension with extractions based on dispersion theory persists at the 2.4-$\sigma$ level. For the strange sigma term, we obtain a non-zero value, ${\sigma }_s=(28.6\pm 9.3)$ MeV.

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Cited by in corpus (8)

• FLAG Review 2024
• 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
• Effective theory tower for $\mu \to e$ conversion
• Illustrating the liquid gas transition of nuclear matter in QCD
• The isoscalar octet axial form factor of the nucleon from lattice QCD
• Nucleon mass: trace anomaly and $\sigma$-terms
• Renormalization-Group Invariant Parity-Doublet Model for Nuclear and Neutron-Star Matter