頁籤選單縮合
題 名 | Sea Quark or Anomalous Gluon Interpretation for gp₁(x)? |
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作 者 | Cheng,Hai-yang; | 書刊名 | Chinese Journal of Physics |
卷 期 | 35:1 1997.02[民86.02] |
頁 次 | 頁25-34 |
分類號 | 330 |
關鍵詞 | |
語 文 | 英文(English) |
英文摘要 | Contrary to what has been oftern claimed in the literature, we clarify that the hard photon-gluon cross section △σ□hard(x) in polarized deep inelastic scattering calculated in the gauge-invariant factorization scheme does not involve any soft contributions and hence it is genuinely hard. We show that the polarized proton structure function gp₁(x) up to the next-to-leading order of α₅ independent of the factorization conveention, e.g., the gauge-invariant or chira-invariant scheme, chosen in defining △σ□hard(x) and the quark spin density. Thereby, it is not pertinent to keep disputing which factorization prescription is correct or which definition for the spin-dependent quark distribution is superior. The hard-gluonic contribution to Γp₁, the first moment of gp₁ (x), is purely factorizatin dependent. Nevertheless, we stress that even though hard gluons do not contribute to Γp₁ in the gauge-invariant scheme, the gluon spin component in a proton, which is factorization independent, should be large enough to perturbatively generate a negative sea polarization via the axial anomaly. We briefly comment on how to study the Q² evolution of parton spin distributions to the next-to-leading order of QCD in the chiral-invariant factorization scheme. |
本系統中英文摘要資訊取自各篇刊載內容。