Speaker
Dr
Oliver Baer
(Humboldt University Berlin)
Description
The nucleon-pion-state contributions to QCD two- and three-point functions used in the calculation of the nucleon axial charge are studied in chiral perturbation theory. For sufficiently small quark masses and large volumes the nucleon-pion states are expected to have smaller total energy than the single-particle excited states. To leading order in chiral perturbation theory the results do not depend on low-energy constants associated with the interpolating nucleon fields and apply to local as well as smeared interpolators. The nucleon-pion-state contribution is found to be at the few percent level and non-negligible for precise determinations of the axial charge.
Primary author
Dr
Oliver Baer
(Humboldt University Berlin)
