Angular momentum sum rule for spin one hadronic systems
  We derive a sum rule for the total quark angular momentum of a spin-one hadronic system within a gauge invariant decomposition of the hadron's spin. We show that the total angular momentum can be measured through deeply virtual Compton scattering experiments using transversely polarized deuteron targets. 
Swadhin K. Taneja, Kunal Kathuria, Simonetta Liuti and Gary R.   Goldstein
hep-ph