Renormalization constants (RCs) of overlap quark bilinear operators on 2 þ 1-flavor domain wall fermion configurations are calculated by using the RI/MOM and RI/SMOM schemes. The scale independent RC for the axial vector current is computed by using a Ward identity. Then the RCs for the quark field and the vector, tensor, scalar, and pseudoscalar operators are calculated in both the RI/MOM and RI/SMOM schemes. The RCs are converted to the MS scheme and we compare the numerical results from using the two intermediate schemes. The lattice size is 48 3 × 96 and the inverse spacing 1=a ¼ 1.730ð4Þ GeV.

No abstract

The ratio of the strange quark momentum fraction hxi sþs to that of light quark u or d in disconnected insertions (DI) is calculated on the lattice with overlap fermions on four domain wall fermion ensembles. These ensembles cover three lattice spacings, three volumes and several pion masses including the physical one, from which a global fitting is carried out. A complete nonperturbative renormalization and the mixing between the quark and glue operators are taken into account. We find the ratio to be hxi sþs =hxi uþū ðDIÞ ¼ 0.795ð79Þð77Þ at μ ¼ 2 GeV in the MS scheme. This ratio can be used as a constraint to better determine the strange parton distribution especially in the small x region in the global fittings of PDFs when the connected and disconnected sea are fitted and evolved separately, demonstrating a new way that connects lattice calculations with global analyses.

No abstract