Electromagnetic form factors of the Ω- In lattice QCD

Abstract

We present results on the omega baryon (Ω-) electromagnetic form factors using Nf=2+1 domain-wall fermion configurations for three pion masses in the range of about 350 to 300 MeV. We compare results obtained using domain-wall fermions with those of a mixed-action (hybrid) approach, which combines domain-wall valence quarks on staggered sea quarks, for a pion mass of about 350 MeV. We pay particular attention in the evaluation of the subdominant electric quadrupole form factor to sufficient accuracy to exclude a zero value, by constructing a sequential source that isolates it from the dominant form factors. The Ω- magnetic moment, μΩ-, and the electric charge and magnetic radius, rE0/M12, are extracted for these pion masses. The electric quadrupole moment is determined for the first time using dynamical quarks. © 2010 The American Physical Society.