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

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

9 Aug 2022, 16:30

20m

CP1-HSZ/1.002 (CP1-HSZ) - HS6 (CP1-HSZ)

Oral Presentation Hadron Structure Hadron Structure

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 $M_{\pi }\approx 0.130\mathrm{MeV}\dots 350\mathrm{MeV}$, four values of the lattice spacing $a\approx 0.05\mathrm{fm}\dots 0.09\mathrm{fm}$ 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 ($T\times L^3=192\times {96}^3$, $M_{\pi }=172\mathrm{MeV}$, $a=0.05\mathrm{fm}$). 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.

Presentation materials

talk_Ottnad.pdf