Indico search will be reestablished in the next version upgrade of the software: https://getindico.io/roadmap/

This search is only for public events. Restricted events are not available.

IMPORTANT! Indico has been upgraded. Please let us know as soon as possible if you find any issues and email indico-support@fnal.gov

36th Annual International Symposium on Lattice Field Theory

22-28 July 2018
Kellogg Hotel and Conference Center
EST timezone

Nucleon-pion-state contamination in the lattice determination of the axial form factors of the nucleon

Jul 25, 2018, 2:00 PM
20m
105 (Kellogg Hotel and Conference Center)

105

Kellogg Hotel and Conference Center

219 S Harrison Rd, East Lansing, MI 48824

Speaker

Dr Oliver Baer (Humboldt University Berlin)

Description

The nucleon-pion-state ($N\pi$) contribution to QCD two- and three-point functions used in the calculation of the axial form factors of the nucleon are studied in chiral perturbation theory. For physical quark masses the $N\pi$ states are expected to dominate the excited-state contamination at large euclidean time separations. To leading order in chiral perturbation theory the results depend on two experimentally well-known low-energy constants only and the $N\pi$-state contamination can be reliably estimated. In the axial form factor $G_A(Q^2)$ it amounts to a 5 percent overestimation for source-sink separations of about 2 fm and shows essentially no dependence on the momentum transfer $Q^2$. In contrast, for the induced pseudo-scalar form factor $G_P(Q^2)$ the $N\pi$-state contamination shows a much stronger dependence on $Q^2$ and leads to a 20-40 percent underestimation of $G_P(Q^2)$ at small momentum transfers.

Primary author

Dr Oliver Baer (Humboldt University Berlin)

Presentation Materials

 lattice2018_obaer.key lattice2018_obaer.pdf