Nucleon to Δ transition form factors with NF=2+1 domain wall fermions

Abstract

We calculate the electromagnetic, axial, and pseudoscalar form factors of the nucleon to Δ(1232) transition using two dynamical light degenerate quarks and a dynamical strange quark simulated with the domain wall fermion action. Results are obtained at lattice spacings a=0.114fm and a=0.084fm, with corresponding pion masses of 330 MeV and 297 MeV, respectively. High statistics measurements are achieved by utilizing the coherent sink technique. The dominant electromagnetic dipole form factor, the axial form factors and the pseudoscalar coupling are extracted to a good accuracy. This allows the investigation of the nondiagonal Goldberger-Treiman relation. Particular emphasis is given on the extraction of the subdominant electromagnetic quadrupole form factors and their ratio to the dominant dipole form factor, REM and RSM, measured in experiment. © 2011 American Physical Society.