Speaker
Mr
Tobias Schulz
(University of Mainz)
Description
One of the most challenging tasks in lattice calculations of hadronic form factors is the analysis and control of excited-state contaminations. Taking the isovector form factors of the nucleon as an example, a simple calculation in chiral effective field theory shows that the excited-state contributions become dominant when the axial current is spatially distant from the nucleon source location. In this case, the distance of the propagating pions, which have been created at the source (or sink), is comparable to the distance of the equal time pion propagation, which corresponds to the ground state contribution of the form factor including the pion pole. We investigate a method on a $N_f=2+1$ flavor CLS ensemble ($\beta=3.55$, $a=0.064\,$fm) with a pion mass of $m_\pi=200\,$MeV using Wilson fermions to address this issue.
Primary author
Mr
Tobias Schulz
(University of Mainz)
Co-authors
Prof.
Harvey B. Meyer
(Johannes Gutenberg University Mainz)
Dr
Konstantin Ottnad
(University of Mainz)