# Nucleon spin structure

${\displaystyle {\frac {1}{2}}={\frac {1}{2}}\Sigma _{q}+\Sigma _{g}+L_{q}+L_{g}.}$
The gluon spin components ${\displaystyle \Sigma _{g}}$ are being measured by many experiments. Quark and gluon angular momenta will be studied by measuring so-called generalized parton distributions (GPD) through deeply virtual compton scattering (DVCS) experiments, conducted at CERN (COMPASS) and at Jefferson Lab, among other laboratories.