The isospin breaking effect on baryons with Nf=2 domain wall fermions

Abstract

We study the isospin breaking effect on octet baryons. Using the two-flavor dynamical domain-wall QCD configurations combined with the quenched non-compact QED configurations, the electromagnetic mass splittings between isomultiplets (p, n), (Sigma^+, Sigma^0, Sigma^-), (Xi^0, Xi^-) are investigated. We evaluate the main source of statistical fluctuations in the two-point correlation function, and find that the elimination of O(e) fluctuation (e: the QED charge) is essential to extract the signal. Preliminary results for $m_p - m_n$ as well as other mass splittings are presented. Possible origin of systematic uncertainty is also discussed.

Talk given at 24th International Symposium on Lattice Field Theory (LATTICE 2006), Tucson, Arizona, USA, 23-28 Jul. 2006 (Hadron Spectroscopy), 7pages, 4figures