We present the current status of our analysis of nucleon structure observables including isovector charges and twist-2 matrix elements as well as the nucleon mass. Results are computed on a large set of CLS Nf=2+1 gauge ensembles with Mπ≈0.130MeV…350MeV, four values of the lattice spacing a=0.05fm…0.09fm and covering a large range of physical volumes. Compared to the results presented at last year's conference we have added data on a very fine and large box at small light quark mass (T×L3=192×963, Mπ=172MeV, a=0.05fm). Additional (intermediate) source-sink separations have been computed on the coarser ensembles, further increasing effective statistics and allowing for a more fine-grained control in the treatment of the excited-state contamination. Excited states in the nucleon matrix elements are tamed by a simultaneous, two-state fit ansatz using the summation method.
@article{arxiv.2212.09940,
title = {Mass and isovector matrix elements of the nucleon at zero-momentum transfer},
author = {Konstantin Ottnad and Dalibor Djukanovic and Harvey B. Meyer and Georg von Hippel and Hartmut Wittig},
journal= {arXiv preprint arXiv:2212.09940},
year = {2022}
}
Comments
10 pages, 4 figures, Talk presented at the 39th International Symposium on Lattice Field Theory, 8th-13th August 2022, Bonn, Germany