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arXiv · hep-ph/9803238

Positivity of NLO Spin-Dependent Parton Distributions

C. Bourrely·E. Leader·O. V. Teryaev
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Abstract

We discuss the positivity of the hadron density matrix in QCD. This basic property is shown to be preserved by QCD evolution, provided the relation $|ΔP_{ij}(z)| \leq P_{ij}$ is valid for all kernels for $z < 1$, and the usual "+" prescription is used. We comment on the positivity restrictions for the choice of the NLO factorization scheme for the evolution of the spin-dependent parton distributions.

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C. Bourrely, E. Leader, O. V. Teryaev. 1998-03-04. Positivity of NLO Spin-Dependent Parton Distributions. https://arxiv.org/abs/hep-ph/9803238

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