臺灣博碩士論文加值系統

我們利用ChPT 來探討SU(3)味對稱性破壞對虛純量介子的光軸波函數及其部分子分佈函數的影響， 我們所計算的twist-3 對光軸波函數的貢獻和之前別人算過的twist-2的貢獻有類似的結果，在算到O(p^2)這階, chiral 對數只是影響到光軸波函數的歸一化，夸克質量對波函數的修正都是可解析的，這對於晶格QCD的外插是十分方便的，利用對稱性破壞的修正，我們可以導出一些介子間twist-3光軸波函數的關係式及介子間twist-2部分子分佈函數的關係式，而這些關係式是獨立於模型的。

The SU(3) flavor symmetry breaking in pseudoscaler meson light-cone wave functions (LWF''s) and parton distribution functions (PDF''s) are studied using chiral perturbation theory. Similar to what was found previously to the twist-2 contributions to (LWF''s), at O(p²), the chiral logarithms of the twist-3 effect only contribute to the normalization of the LWF''s - the quark mass corrections to the shape of the LWF''s is purely analytic. This is convenient for chiral extrapolations of the corresponding lattice QCD results. With the symmetry violation correction we derive useful model independent relations between psedoscaler Goldstone boson twist-3 LWF''s and twist-2 PDF''s.

Content
Abstract ii
1 Introduction 1
2 π to vacuum twist-3 matrix elements 3
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2 Calculating π→0 twist-3 matrix elements using ChPT . . . . . . . . . . . 5
2.3 Relation among the π,K, and η twist-3 light-cone wave functions 9
2.4 Relate our results traditional pion decay constants f_{M} and pion masses M_{M}² 12
2.5 Another similar twist-3 operator . . . . . . . . . . . . . . . . . . . . 14

3 Forward twist-2 matrix element for mesons π, K and η 17
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.2 Light-cone twist-2 forward matrix element . . . . . . . . . . . . . . . . 17
3.2.1 ChPT calculation results . . . . . . . . . . . . . . . . . . . . 20
3.2.2 Quark model prediction . . . . . . . . . . . . . . . . . . . . 24
3.3.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Summary 28

A Appendix : Introduction to theoretical background 30
A.1 Light-cone operator product expansion and twist . . . . . . . . . . . . . 30
A.2 Chiral Perturbation Theory (ChPT) . . . . . . . . . . . . . . . . . . 30

Reference 32

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