Ja n 20 06 Checking the Burkardt sum rule for the Sivers function by model calculations

The Sivers mechanism gives rise to a non-zero average transverse momentum of partons inside a transversely polarized target. According to a sum rule of Burkardt this transverse momentum vanishes when summing over all partons. We explicitly check the Burkardt sum rule by means of one-loop calculations for a quark target in perturbative QCD and for a diquark… (More)

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