English

Mass and isovector matrix elements of the nucleon at zero-momentum transfer

High Energy Physics - Lattice 2022-12-21 v1

Abstract

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+1N_f=2+1 gauge ensembles with Mπ0.130MeV350MeVM_\pi\approx0.130\mathrm{MeV}\ldots 350\mathrm{MeV}, four values of the lattice spacing a=0.05fm0.09fma=0.05\mathrm{fm}\ldots 0.09\mathrm{fm} 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=192×963T\times L^3=192 \times 96^3, Mπ=172MeVM_\pi=172\mathrm{MeV}, a=0.05fma=0.05\mathrm{fm}). 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.

Keywords

Cite

@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