Abstract
A covariant version of the quark–parton model is studied. The dependence of the structure functions and parton distributions on the 3D intrinsic motion of the quarks is discussed. The important role of the orbital momentum of the quark, which is a particular case of intrinsic motion, appears as a direct consequence of the covariant description. The effect of the orbital motion is substantial, especially for polarized structure functions. At the same time, the procedure for obtaining the momentum distributions of polarized quarks from the combination of polarized and unpolarized structure functions is suggested.
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References
E142 Collaboration, P.L. Anthony et al., Phys. Rev. D 54, 6620 (1996)
E154 Collaboration, K. Abe et al., Phys. Rev. Lett. 79, 26 (1997)
HERMES Collaboration, K. Ackerstaff et al., Phys. Lett. B 404, 383 (1997)
HERMES Collaboration, A. Airapetian et al., Phys. Lett. B 442, 484 (1998)
Spin Muon Collaboration, B. Adeva et al., Phys. Rev. D 58, 112001 (1998)
E143 Collaboration, K. Abe et al., Phys. Rev. D 58, 112003 (1998)
E155 Collaboration, P. Anthony et al., Phys. Lett. B 493, 19 (2000)
E155 Collaboration, P. Anthony et al., Phys. Lett. B 553, 18 (2003)
K. Imai et al., (Eds.), Proc. 17th International Spin Physics Symposium – SPIN 2006, Kyoto, Japan, 2–7 October 2006 (American Institute of Physics, New York, 2007)
M. Anselmino, A.V. Efremov, E. Leader, Phys. Rep. 261, 1 (1995)
P. Zavada, Phys. Rev. D 55, 4290 (1997)
P. Zavada, Phys. Rev. D 65, 0054040 (2002)
P. Zavada, Phys. Rev. D 67, 014019 (2003)
A.V. Efremov, O.V. Teryaev, P. Zavada, Phys. Rev. D 70, 054018 (2004) [hep-ph/0512034]
L.M. Sehgal, Phys. Rev. D 10, 1663 (1974)
L.M. Sehgal, Phys. Rev. D 10, 2016 (1974) [Erratum]
P.G. Ratcliffe, Phys. Lett. B 192, 180 (1987)
A. Abbas, J. Phys. G 16, L21 (1990)
A. Abbas, J. Phys. G 15, L73 (1989)
J. Keppler, H.M. Hofmann, Phys. Rev. D 51, 3936 (1995)
M. Casu, L.M. Sehgal, Phys. Rev. D 55, 2644 (1996)
B.-Q. Ma, I. Schmidt, Phys. Rev. D 58, 096008 (1998)
S.J. Brodsky, D.S. Hwang, B.-Q. Ma, I. Schmidt, Nucl. Phys. B 593, 311 (2001)
M. Wakamatsu, T. Watabe, Phys. Rev. D 62, 054009 (2000)
M. Wakamatsu, Y. Nakakoji, Phys. Rev. D 74, 054006 (2006)
X. Song, Int. J. Mod. Phys. A 16, 3673 (2001)
X. Ji, J.-P. Ma, F. Yuan, Nucl. Phys. B 652, 383 (2003)
A.D. Martin, R.G. Roberts, W.J. Stirling, R.S. Thorne, hep-ph/0411040
E. Leader, A.V. Sidorov, D.B. Stamenov, Phys. Rev. D 73, 034023 (2006)
Z. Liang, T. Meng, Z. Phys. A 344, 171 (1992)
L.D. Landau, E.M. Lifshitz et al., Quantum Electrodynamics, Course of Theoretical Physics, vol. 4 (Elsevier Butterworth Heinemann, Oxford, 1982)
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13.60.-r; 13.88.+e; 14.65.-q
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Závada, P. Parton distribution functions and quark orbital motion. Eur. Phys. J. C 52, 121–131 (2007). https://doi.org/10.1140/epjc/s10052-007-0360-1
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DOI: https://doi.org/10.1140/epjc/s10052-007-0360-1