# The 39th International Symposium on Lattice Field Theory (Lattice 2022)

Aug 8 – 13, 2022
Hörsaalzentrum Poppelsdorf
Europe/Berlin timezone

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

Aug 9, 2022, 4:30 PM
20m
CP1-HSZ/1st-1.002 - HS6 (CP1-HSZ)

50

### Speaker

Dr Konstantin Ottnad (University of Mainz)

### Description

We present the current status of our analyis 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 $N_f=2+1$ gauge ensembles with $M_\pi\approx 0.130\mathrm{MeV} \ldots 350\mathrm{MeV}$, four values of the lattice spacing $a\approx0.05\mathrm{fm}\ldots0.09\mathrm{fm}$ 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 ($T\times L^3 =192\times 96^3$, $M_\pi=172\mathrm{MeV}$, $a=0.05\mathrm{fm}$). Besides, 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. The physical extrapolation for all observables including the nucleon mass can be carried out in a global fit.

### Primary author

Dr Konstantin Ottnad (University of Mainz)

### Co-authors

Dr Dalibor Djukanovic Georg von Hippel (JGU Mainz) Hartmut Wittig Harvey B. Meyer (Johannes Gutenberg University Mainz)