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

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 $N_f=2+1$ gauge ensembles with $M_{\pi }\approx 0.130\mathrm{M}\mathrm{e}\mathrm{V}\dots 350\mathrm{M}\mathrm{e}\mathrm{V}$, four values of the lattice spacing $a=0.05\mathrm{f}\mathrm{m}\dots 0.09\mathrm{f}\mathrm{m}$ 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 ($T\times L^3=192\times {96}^3$, $M_{\pi }=172\mathrm{M}\mathrm{e}\mathrm{V}$, $a=0.05\mathrm{f}\mathrm{m}$). 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.