6533b827fe1ef96bd1286f7a

RESEARCH PRODUCT

The nucleon sigma terms with $N_f = 2 + 1$ O($a$)-improved Wilson fermions

Andria AgadjanovDalibor DjukanovicGeorg Von HippelHarvey B. MeyerKonstantin OttnadHartmut Wittig

subject

Nuclear Theory (nucl-th)High Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)High Energy Physics - LatticeNuclear TheoryHigh Energy Physics - Lattice (hep-lat)FOS: Physical sciences

description

We present a lattice-QCD based analysis of the nucleon sigma terms using gauge ensembles with $N_f = 2 + 1$ flavors of ${\cal O}(a)$-improved Wilson fermions, with a complete error budget concerning excited-state contaminations, chiral extrapolation as well as finite-size and lattice spacing effects. We compute the sigma terms determined directly from the matrix elements of the scalar currents. For the pion nucleon sigma term, we obtain $\sigma_{\pi N} = (43.6\pm3.8)$ MeV, where the error includes all systematics. The tension with extractions based on dispersion theory persists at the 3-$\sigma$ level. For the strange sigma term, we obtain a non-zero value, $\sigma_s=(27.1\pm9.8)$ MeV.

http://arxiv.org/abs/2303.08741