English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We present a calculation of the strange and charm quark contributions to thenucleon spin from the anomalous Ward identity (AWI). It is performed withoverlap valence quarks on 2+1-flavor domain-wall fermion gauge configurationson a $24^3 \times 64$ lattice with the light sea mass at $m_{\pi} = 330$ MeV.To satisfy the AWI, the overlap fermion for the pseudoscalar density and theoverlap Dirac operator for the topological density, which do not havemultiplicative renormalization, are used to normalize the form factor of thelocal axial-vector current at finite $q^2$. For the charm quark, we find thatthe negative pseudoscalar term almost cancels the positive topological term.For the strange quark, the pseudoscalar term is less negative than that of thecharm. By imposing the AWI, the strange $g_A(q^2)$ at $q^2 =0$ is obtained by aglobal fit of the pseudoscalar and the topological form factors, together with$g_A(q^2)$ and the induced pseudoscalar form factor $h_A(q^2)$ at finite $q^2$.The chiral extrapolation to the physical pion mass gives $\Delta s + \Delta{\bar{s}} = -0.0403(44)(78)$.

Strange and Charm Quark Spins from Anomalous Ward Identity