Transverse Spin Structure of the Nucleon from Lattice-QCD Simulations

Journal Article · Fri Jun 01 04:00:00 EDT 2007 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.98.222001· OSTI ID:20951444

Goeckeler, M; Schaefer, A ^[1]; Haegler, Ph ^[2]; Horsley, R; Zanotti, J M ^[3]; Nakamura, Y; Pleiter, D ^[4]; Rakow, P E. L. ^[5]; Schierholz, G ^[6]; Stueben, H ^[7]

---

1. Institut fuer Theoretische Physik, Universitaet Regensburg, 93040 Regensburg (Germany)
2. Physik-Department der TU Muenchen, Institut fuer Theoretische Physik T39, James-Franck-Strasse, 85747 Garching (Germany)
3. School of Physics, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom)
4. John von Neumann-Institut fuer Computing NIC/DESY, 15738 Zeuthen (Germany)
5. Theoretical Physics Division, Department of Mathematical Sciences, University of Liverpool, Liverpool L69 3BX (United Kingdom)
6. Deutsches Elektron-Synchrotron DESY, 22603 Hamburg (Germany)
7. Konrad-Zuse-Zentrum fuer Informationstechnik Berlin, 14195 Berlin (Germany)

We present the first calculation in lattice QCD of the lowest two moments of transverse spin densities of quarks in the nucleon. They encode correlations between quark spin and orbital angular momentum. Our dynamical simulations are based on two flavors of clover-improved Wilson fermions and Wilson gluons. We find significant contributions from certain quark helicity flip generalized parton distributions, leading to strongly distorted densities of transversely polarized quarks in the nucleon. In particular, based on our results and recent arguments by Burkardt [Phys. Rev. D 72, 094020 (2005)], we predict that the Boer-Mulders function h{sub 1}{sup perpendicular}, describing correlations of transverse quark spin and intrinsic transverse momentum of quarks, is large and negative for both up and down quarks.

• OSTI ID: 20951444
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 22 Vol. 98; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
D QUARKS
FLAVOR MODEL
GLUONS
HELICITY
ORBITAL ANGULAR MOMENTUM
QUANTUM CHROMODYNAMICS
SIMULATION
SPIN
TRANSVERSE MOMENTUM
U QUARKS