Disconnected contributions to the spin of the nucleon

  title={Disconnected contributions to the spin of the nucleon},
  author={A. J. Chambers and R. Horsley and Y. Nakamura and Holger Perlt and Dirk Pleiter and P. E. L. Rakow and G. Schierholz and Arwed Schiller and Hinnerk Stuben and Ross D. Young and James Zanotti},
  journal={Physical Review D},
The spin decomposition of the proton is a long-standing topic of much interest in hadronic physics. Lattice QCD has had much success in calculating the connected contributions to the quark spin. However, complete calculations, which necessarily involve gluonic and strange-quark contributions, still present some challenges. These "disconnected" contributions typically involve small signals hidden against large statistical backgrounds and rely on computationally intensive stochastic techniques… 

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  • Phys. Rev. D 90,
  • 2014


  • Rept. 261, 1
  • 1995


  • Lett. B663, 302
  • 2008

I and J


  • Lett. B 704, 89
  • 2011


  • Rev. D 92, 031501
  • 2015


  • Rev. D71, 054506
  • 2005


  • Rev. D 85, 054510
  • 2012


  • Rev. D 89, 094502
  • 2014